Antibacterial or wound care materials, devices and uses

Abstract

An antimicrobial material which is a composite of a flexible hydrophilic polymer foam or fiber matrix comprising two matrix surfaces providing a release surface and a back surface, or two release surfaces, and a structural matrix framework between them defining a network of cells having a cell network surface and a network of pores or cell openings therein, and a powder charge component comprising an antimicrobial additive or a wound care additive, wherein the powder charge is contained on one or both of the surfaces and / or within the cell network, the composite being an assembly of a preformed matrix component and a powder charge component, and an asymmetric material which is asymmetric in view of the distribution of the powder charge therein, and wherein the powder charge comprises a flow agent and / or a bulking agent and / or a binder, the additive and / or flow agent being disposed together with the bulking agent and / or the binder, a device comprising the composite, a method of manufacture thereof comprising assembling the matrix and the powder charge, and uses thereof.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority to UK Provisional Application No. 1711183.2, filed on July 12, 2017, which is incorporated herein by reference in its entirety.

[0002] This application discloses antibacterial or wound care materials and devices, methods for their manufacture, their use, and methods of treatment therewith. The materials and devices include antibacterial additive powders or wound dressing additive powders loaded thereon or therein, such as being loaded asymmetrically thereon or therein, for effective release rate, release profile, and / or reproducibility of release.

Background Art

[0003] Silver - impregnated antibacterial wound dressings exist as products containing silver salts, particularly silver nitrate, silver sulfadiazine, or silver sulfate, as antibacterial additives, in combination with a porous absorbent matrix such as a woven and non - woven fibrous article or a polyurethane foam that treats exudate from the wound. The silver salts are typically combined with the porous matrix via a liquid phase solution or suspension. This may be during the manufacture of the absorbent matrix itself, for example, during the polymerization reaction of a polyurethane foam, where the silver salt is suspended or dissolved in the aqueous reaction phase or by treating the absorbent matrix in an immersion or reaction bath.

[0004] There is an increasing need for wound dressings that remain in a fixed position for long periods during dressing changes, delivering a sustained release of antibacterial silver ions while still delivering that (up - front or rapid) bolus release. This has led to the use of low - solubility silver salts in wound dressings. However, the low solubility of such silver salts limits the amount of salt that can be introduced by conventional solution - manufacturing routes. The bolus release from such limited amounts of low - solubility salts may not be high enough to inhibit or kill bacteria and may be difficult to control for sustained release.

[0005] Attempts to address these limitations, such as the introduction of a combination of a silver salt and a polyurethane foam dissolved and dispersed during the polymerization reaction, and the introduction of the silver salt into multiple layers of a multilayer wound dressing material including a hydrophilic foam and a film, have met with limited success. SUMMARY OF THE INVENTION

[0006] These needs are met by providing an antibacterial material that is readily available, i.e., has a high effective surface area, is readily accessible within the matrix, and / or contains a low solubility silver salt present at a high concentration, and / or by providing the silver salt at the necessary location within the material with differentiated or engineered availability, i.e., efficient and effective availability for bolus and sustained release, regardless of solubility.

[0007] Provided herein is an antibacterial material comprising a porous absorbent fiber or foam matrix, the matrix comprising a powder charge of an antibacterial release additive loaded in powder form on and / or within a pre-formed matrix. More specifically, provided herein is an antibacterial wound dressing material comprising a porous absorbent foam matrix such as a polyurethane (PU) foam matrix or a porous absorbent fiber matrix, and a powder charge of an antibacterial species release additive, more specifically an iodine release additive or a silver ion release additive. Iodine and silver ions are very effective antibacterial agents.

[0008] Further provided herein is a wound dressing material comprising a porous absorbent fiber or foam matrix, the matrix comprising a powder charge of an additive loaded asymmetrically in powder form within the pre-formed matrix.

[0009] Advantageously, the powder charge is a powder form additive charged to the surface and / or cells of the matrix and is readily available for antibacterial release. The powder charge is dry loaded, i.e., loaded onto or into the matrix by a dry processing route. The powder charge retains its powder form during and after loading. The materials herein are imparted with the additive properties of a powder charge dry loaded thereon and / or therein. For example, the antibacterial materials herein are of an antibacterial release profile such as rapid release and / or high release of antibacterial, characteristics of a powder charge dry loaded antibacterial release additive.

[0010] Advantageously, the additive may be selected regardless of density or water solubility, and may be included in the materials herein in an effective amount, for example, an antibacterial effective amount, even if it is of high density or poorly water soluble. More specifically, the additive can be loaded onto a foam or fiber matrix such as a polyurethane (PU) foam or a natural or synthetic fiber matrix without problems presented by limited solubility or maintenance of a non-sustained suspension of solids in a liquid. Advantageously, the materials herein can be characterized by a highly reproducible additive loading such as symmetric or asymmetric additive loading, regardless of the matrix thickness or absorbency, and / or in a reproducible additive administration.

[0011] In embodiments, herein, A flexible hydrophilic polymer foam or fiber matrix component comprising two matrix surfaces providing a release surface and a back surface, or two release surfaces, and between them, a network of cells having a cell network surface and therein a structural matrix framework defining a network of pores, herein also referred to as cell openings or cell windows, An antibacterial material is provided which is a composite of a powder charge component containing an antibacterial additive, the additive being an antibacterial species release additive, The powder charge is included on one or both of the release surfaces and / or within the cell network.

[0012] The antibacterial species is preferably selected from one or more atomic species and one or more diatomic species and combinations thereof.

[0013] The composite preferably includes a pre-formed matrix and an assembly of pre-formed powdered charge, i.e., each of the matrix and the powdered charge is a pre-formed component to be assembled into the composite as defined herein. More specifically, the composite is an assembly of the matrix in matrix form and the antibacterial additive in powder form.

[0014] The powdered charge preferably does not exist in the structural matrix framework or exists in an incidental or minor amount within the structural matrix framework. The powdered charge that exists in an incidental or minor amount within the structural matrix framework preferably exists locally with respect to the powdered charge contained within the surface or the plurality of surfaces and / or within the cell network.

[0015] The pore network herein may be a meandering pore network having few gaps and / or low-frequency pores or cell openings, or a reticulated pore network having many gaps and / or high-frequency pores or cell openings, i.e., a net-like pore network.

[0016] In an embodiment, the matrix provides a meandering pore network and the material includes a powdered charge whose concentration decreases as the depth within the cell network proximal to the release surface or surfaces and / or within the cell network from one or both of the surfaces increases. For example, the matrix resembles a surface-loaded filter or a depth-loaded filter. In an alternative embodiment, the matrix provides a reticulated pore network and the material includes a powdered charge uniformly loaded across the cell network. For example, the matrix resembles a scaffold.

[0017] In an embodiment, the powder charge is retained on the surface or surfaces and / or within the cells by the action of a binder and / or by its mechanical retention by the meandering of the cell network and / or by the cell size and / or by the intercellular pore size. For example, the interconnectivity of the cells is smaller than the cell size itself, by means of "windows" between the cells that limit the possibility of the loaded powder charge falling out of the cell network and thus out of the matrix. This also leads to large meandering within the matrix, which is advantageous for achieving asymmetry in loading as the powder charge has to navigate a meandering path through the matrix. Examples of meandering cell interconnectivity are, without limitation, in the context of a polyurethane foam, "closed cells" containing small interconnecting windows or pores within the cell walls, or a network with "open cells" or struts defining pores, as illustrated in FIGS. 3a and 3c.

[0018] Furthermore, herein, a flexible hydrophilic polymer foam or fiber matrix comprising a front and a back surface facing the wound, or two surfaces facing the wounds, and between them a network of cells having a cell network surface and a structural matrix framework defining a network of pores or cell openings therein, and a powder charge comprising a wound dressing additive or a combination thereof, is provided, the matrix providing a meandering pore network, the powder charge being contained on the surface facing the wound or the back surface and within the cell network in the cells proximal to the surface, more specifically in decreasing amounts as the depth within the network increases.

[0019] The wound dressing additive or its combination in this specification is preferably selected from wound dressing additives selected from any of the antibacterial species-releasing additives defined above or below, and combinations with antibacterial agents, bacteria, bacteriostatic agents, refractory materials, activated carbon or bentonite for odor control, protein destruction or denaturation, absorption, conduction, structural support, absorbents such as superabsorbent polymers (SAP), color or color masking (fluorescent dyes, antioxidants) such as prevention of yellowing of PU foam, and viscosity modifiers, etc.

[0020] The first advantageous embodiment of the present invention is specific to antibacterial species-releasing additives and facilitates the control of the particle size of additive powders such as silver salts. This is particularly relevant when a specific particle size (e.g., micron particle size) improves the release of antibacterial species such as silver ions. When using liquid phase loading, i.e., wetting treatment, the particle size of the salt or additive of interest can vary greatly depending on temperature, concentration, and solubility. By keeping the powder additive dry during loading onto or into the matrix or the finished antibacterial porous material, in the present invention, changes in particle size during processing are avoided. The advantages herein may further be relevant to materials and methods comprising wound dressing additives that are affected by particle size, or water content or hydration or both.

[0021] The second particularly advantageous embodiment herein comprises a powder charge of an additive such as an antibacterial additive (e.g., silver salt) located on the matrix surface and / or on the cell network, thereby being readily available for contact with the fluid at the site and, for example, for absorption of the fluid or release of antibacterial species. Thus, the dosage of the additive used can potentially be reduced, or loaded with a greater or faster effect, compared to other loading techniques using additives that are not readily available, such as those introduced at the time of manufacture of the porous matrix. This results in an improved safety profile of materials such as wound dressing materials without sacrificing performance, or provides a more effective material such as an antibacterial material that provides a higher log reduction of microorganisms or can kill a wider range of microorganisms.

[0022] A further advantageous embodiment of the present specification is that the basis weight of the porous matrix component does not affect the loading amount, facilitating the control of the recommended dosage. For example, this is in contrast to the way additives are combined at the time of manufacturing the porous matrix.

[0023] An advantageous embodiment of the present specification enables the use of additives with high density or slightly water-soluble, such as silver sulfate, without the need for a liquid phase or wet treatment. The production of the material is simple and cost-effective, eliminating the need for a large amount of solvent, which is accompanied by inherent waste and treatment issues.

[0024] A further advantageous embodiment of the present specification provides a high concentration of additives. For example, the dry-loaded powder can be loaded at any desired concentration, quickly, simply, and effectively. This is in contrast to the prior art wet treatment methods, i.e., solution / dispersion methods. The present invention is not the subject of solubility limits or non-sustainable suspensions, or is not affected by them.

[0025] The composite materials in the present specification can be understood in their ordinary meaning. For example, a composite material can be defined by its theoretical ability to disassemble and restore its components intact by inverting its assembly. The powder charge contained within the matrix surfaces and / or cells of the present specification retains its identity prior to assembly, and ignoring retention by meandering of the pore network or embedding in the cell surface, etc., can be theoretically recovered by dropping it from the surface and from the cell by the pore network. Similarly, the matrix retains its identity prior to assembly, and ignoring the embedding can be theoretically recovered by dropping the powder charge without requiring the destruction of the matrix fibers, i.e., the structural matrix framework.

[0026] The composite antibacterial material retains the characteristics of pre-formed or pre-manufactured components and powder charges, such as powder charge characteristics like flexibility or softness matrix identification, release, absorption, solubility, or surface area, or the hydration or water content of the individual particles or powders that make up the powder charge. The wet treatment generally reduces the flexibility and softness matrix characteristics and particle surface area characteristics.

[0027] Accordingly, the composites herein are different from prior art materials containing powders that are dissolved or dispersed in solution, applied to a matrix and dried in situ or mixed into a reactive foam in subsequent matrix formation, whereby in either case the identity of the starting powder is lost or changed. In the latter case, the identity of the starting matrix can also be lost in the theoretical restoration of additives from the structural matrix network.

[0028] The composites herein can be conveniently defined as the intimate combination of the matrix and the powder charge, such as dry fill, solid phase fill or airborne solid phase fill powder charge.

[0029] The cells and cell networks herein can be any interconnected cells, voids or free spaces and their networks contained within a structural matrix framework, such as within a polymer foam or within a woven or non-woven fabric. The pores and pore networks herein include any pores, cell openings or windows that interconnect adjacent cells, and their networks. The pores and pore networks herein permit the permeation of fluids (liquids and gases) between cells and provide a fluid path. The pore network preferably includes pores of limited gaps and frequency that are not aligned, thereby impeding air permeation in a tortuous fluid path.

[0030] The antimicrobial species-releasing additives herein are additives that can release antimicrobial species, which are defined by being activated by a release event involving contact with a wet or aqueous medium. Therefore, it is preferred that the antimicrobial species-releasing additive or a part thereof is soluble or leachable in water and has a solubility exceeding 0.15 mg / L at 25°C. The materials and matrices defined herein are preferably stored away from a wet or aqueous medium, for example, packaged in a non-permeable package. Thereby, early release of the antimicrobial species is avoided.

[0031] The powders herein can take their ordinary meaning and can be understood as fine dry particles, including agglomeration and coagulation defined as first particles and second particles. The first particles are characterized by particle size or, in the case of a range of particle sizes, by particle size distribution.

[0032] The agglomeration and coagulation of the first particles defined as second particles have a surface area that is the same as or similar to the cumulative surface area of the first particles. Therefore, individual agglomerates, coagulates, or second particles generally have a larger surface area than a single first particle of the corresponding size.

[0033] References herein to powder charges are references to powder charges delivered to and contained within the matrix. The powder charge may be a non-quantitative charge or a quantitative charge. For example, the powder charge delivered to the matrix may be wholly or partly contained within the material.

[0034] The powder charge may be a batch or discontinuous charge or a continuous charge, for example, a charge of the entire powder charge onto or into a discontinuous matrix such as a sheet matrix, or a charge per unit volume or area onto or into a continuous matrix such as a roll or web of the matrix.

[0035] The powder charge of the additive can be variously referred to herein as a powder charge, a powder-loaded additive, or a dry-loaded additive. As used herein, "dry-loaded" or "powder-loaded" is simply understood to indicate the phase of the powder charge and / or its loading method, such as a "solid-phase loaded" additive, an "airborne solid-phase loaded" additive, etc., and is not intended to indicate the ambient water content.

[0036] The powder charge herein may be free-flowing or may be fixed, for example, at least partially embedded within the cell network surface. Importantly, however, the embedding has no or only an incidental effect on the first particle size.

[0037] In an embodiment, the material has an asymmetry in view of the additive, where the powder charge is contained within one surface of the matrix surface, for example, the release surface or the surface facing the wound, or the back surface and / or the cell network proximal thereto, and is not present or is present in an incidental or minor amount within the other surface of the matrix and / or the cell network proximal thereto. The release surface provides more rapid antibacterial release, fluid absorption, etc. than the back surface, such that the release surface can be provided to face the surface facing the microorganism, or the first microorganism, for example, to be disposed facing the wound surface. The surface facing the wound or the back surface can provide more rapid fluid absorption, color masking, or other additive properties defined herein.

[0038] Alternatively, the material has a symmetry in view of the distribution of the additive, where the powder charge is contained within both surfaces and / or the cell network proximal thereto. The material can provide rapid antibacterial release, fluid absorption, color masking, etc. on either or both of the matrix surfaces. Any surface can be provided to face the surface facing the microorganism or the wound, for example, to be disposed towards a site such as the wound surface. Thus, the material can provide a choice of the surface facing the microorganism, the site, or the wound.

[0039] In an embodiment, the powder charge is present on the surface or surfaces, and is not present, or is present in an incidental or minor amount, within the cell network and within the structural matrix framework.

[0040] In an embodiment, the powder charge is present on the surface or surfaces and within the cell network across the matrix.

[0041] The material preferably has an asymmetry in view of the additive, where the powder charge is preferably present on one or both of the surfaces and within the cell network proximal to one of the surfaces. The powder charge is not present, or is present in an incidental or minor amount, within the cell network proximal to the back surface and within the structural matrix framework.

[0042] Alternatively, the powder charge is present on both of the surfaces and within the cell network proximal to each of the surfaces (symmetric).

[0043] In an embodiment, the materials herein present a choice of an antibacterial-releasing surface, a surface facing a wound, etc., i.e., the material is not hand-processed and is adapted to be processed at the site, either directly or within a device, to contact any surface proximal to the site. Alternatively, the materials herein are hand-processed and are adapted to be processed at the site, either directly or within a device, to contact an additive-rich surface proximal to or remote from the site.

[0044] The powder charge herein may be loaded uniformly, asymmetrically, or loaded with a decreasing amount within the cell network as the depth within the matrix increases, e.g., the amount or concentration may decrease as the distance from the surface or each surface increases. The concentration at the surface may be in a continuous profile, or the concentration or amount within the cell network may be in a discontinuous profile having a function of independently manipulating each concentration or amount during its assembly.

[0045] The powder charge may extend from one or each of the matrix surfaces by 5% to 100% (such as 85% or 50%) of the separation between the surfaces, for example, may extend inwardly from the surface or the plurality of surfaces to a diameter of cells with an average size of 2 to 6.

[0046] In an embodiment, the materials herein include a powder charge or a plurality of powder charges that together or individually contain an antibacterial additive and a superabsorbent polymer (SAP).

[0047] In an embodiment, the materials herein include a powder charge or a plurality of powder charges that contain the wound dressing additive as defined above together with an antibacterial additive or SAP. The plurality of powder charges may be contained on the same or different surfaces and / or within the cell network proximal thereto.

[0048] In an embodiment, the matrix herein may contain the same or different antibacterial species-releasing additives impregnated in the same or different additives, for example, the background content or supplementary content within the structural matrix framework of the materials herein, and the background or supplementary content may be contained within a pre-formed matrix, that is, introduced into a pre-formed matrix other than the powder charge. The background additive content remains impregnated, thereby being protected from leaching from the structural matrix framework during the assembly of the matrix and the powder charge components into the materials as defined herein.

[0049] In an embodiment, the powder charge is located or embedded within one or more surfaces of the matrix and / or within the network surface, preferably partially incorporated and protruding therefrom. Positioning or embedding prevents or limits the powder charge from falling off from the matrix surface and / or from the cell network.

[0050] Alternatively or additionally, the materials herein can form a laminate with one or more powder charge retaining fluid permeable nets. The powder charge provided within the cell network defined above can be further retained within the cell network defined above by its meandering or by cell and / or pore size.

[0051] In this embodiment, the materials herein include an adhesive having a solubility of less than 100 g / L (25 °C), more preferably 10 g / L (25 °C). Such additives are preferably present on the surface and / or within the cell network at a concentration exceeding the concentration that can be provided by absorption of the additive from a saturated solution and drying.

[0052] In an embodiment, the powder charges herein included both in the matrix surface and within the cell network are provided at independently differentiated amounts and at concentrations adapted to the required total additive properties such as its release profile. Advantageously, the composite materials herein provide the function of independently differentiating or manipulating the powder charges included in each of the matrix surface and the cell network during its assembly. For example, for a given material, the proportion of the powder charge at the matrix release surface can be greater than, equal to, or less than its proportion within the cell network.

[0053] The matrix herein or a part thereof preferably includes a foam matrix selected from natural and synthetic polymer foams such as polystyrene, styrene copolymers, polyvinyl chloride, polyvinyl alcohol, polyurethane, phenolic polymers, silicone, polyolefins, rubbers and elastomer thermoplastic polymers and combinations and copolymers thereof.

[0054] The matrix of this specification, or a part thereof, preferably comprises a fibrous matrix selected from woven or non-woven fibrous matrices of any natural or synthetic fiber, including absorbents and superabsorbents such as cellulose, alginic acid, chitin, chitosan, rayon, and viscose, and functional derivatives thereof, and mixtures thereof. The matrix may include foams and / or fiber bilayers or multilayers.

[0055] The atomic species or diatomic species of this specification may or may not be loaded. The antibacterial atomic species are preferably antibacterial ions, more preferably antibacterial cations, and most preferably silver cations. The antibacterial diatomic species are preferably not loaded, and more preferably are homonuclear diatomic species such as I2. The antibacterial species release additive defined above may release additional antibacterial species, such as the water-soluble degradation form of iodine.

[0056] The antibacterial atomic release or diatomic release additive is preferably selected from silver element, silver salts, silver complexes, the caged form of silver, and caged iodine and combinations thereof, more preferably from silver salts, silver complexes and their caged forms, and from caged iodine.

[0057] Preferably, therefore, in this specification, a flexible hydrophilic polymer foam or fibrous matrix is provided, including two matrix surfaces that provide a release surface and a back surface, or two release surfaces, and between them, a network of cells having a cell network surface and a structural matrix framework that defines a network of pores or cell openings therein. An antibacterial material is provided which is a composite material with a powder charge containing an antibacterial species release additive, wherein the species is selected from antibacterial atomic species and antibacterial diatomic species. The powder charge is contained on the surface or the plurality of surfaces, and / or within the cell network, and the antibacterial additive is selected from silver element, silver complex, silver salt, the caged form of silver, caged iodine, and combinations thereof.

[0058] The silver complex and silver salt are preferably selected from colloidal silver, silver zeolite, silver sulfadiazine, silver sulfate, silver carbonate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate, and combinations thereof. The caged iodine is preferably selected from cadexomer iodine.

[0059] The SAP herein can be selected from known medical grade superabsorbent polymers such as sodium polyacrylate, cross-linked CMC or cellulose derivatives functionalized with other absorbents (by carboxylation or sulfonation), cross-linked polyethylene oxide, and PVA copolymers.

[0060] The powder formulation herein may additionally contain a flow agent. The flow agent is included in the formulation together with the additive particles and provides improved powder handling. The additive is preferably arranged together with the flow agent.

[0061] The flow agent can reduce or inhibit additive aggregation or agglomeration, aid in the flow or lubrication of the powder formulation, and inhibit caking. The flow agent can facilitate the uniform administration of the additive to the surface and further reduce the waste, cleaning, and maintenance of the treatment equipment. The flow agent may be a high melting point insoluble powder such as stearate, clay, silica, carbon, or graphite. The flow agent may have a first particle size that is the same as or different from the additive herein.

[0062] The material or powder formulation herein may contain a bulking agent included on the matrix surface and / or within the cell network on its surface, together with the powder formulation, as part of the powder formulation, or as a solid melt or partial melt. The additive is preferably arranged together with the bulking agent or its solid melt or its partial melt.

[0063] The bulking agent is a powder diluent that increases the volume of the powder charge. The bulking agent can facilitate the accurate and reproducible administration of the powder charge into and within the matrix of this specification. The bulking agent can be particularly beneficial when dosing accuracy is required. The bulking agent can facilitate directing the powder charge within the cell network and especially at a given depth within the network. The bulking agent may have a smaller particle size than the additives of this specification and be included at a greater depth within the cell network, or may have a larger particle size than the additives and be included at a shallower depth within the cell network.

[0064] The bulking agent is water-permeable. The water permeability allows fluid permeation in the cell network. The bulking agent may be a low softening point or low melting point material such as PEG, PVP, etc. The bulking agent is provided together with the powder charge components in powder form. The bulking agent contained in the molten form of the material can provide binding of the powder charge to the matrix.

[0065] The SAP contained in the powder charge of this specification can provide the material as a final product with a bulking agent function during manufacture in addition to the absorbent function.

[0066] The materials of this specification can contain a binder together with the powder charge on the matrix surface and / or within the cell network. The binder is included as a solid melt or partial melt. The binder is provided in powder form together with the powder charge components and may be the same or a different component from the bulking agent defined above. The additives are arranged together with the solid melt or partial melt binder.

[0067] The binder of this specification is non-adhesive at ambient temperature and softens at elevated temperatures of 20°C to 90°C, for example 30°C to 90°C. The binder adheres to the matrix and the powder charge by transition softening. The material containing the binder retains the fluid permeability characteristics at the matrix surface and fluid absorption through the matrix surface.

[0068] In the embodiments of this specification, Two matrix surfaces providing a release surface and a back surface, or two release surfaces, and therebetween, a network of cells having a cell network surface and a structural matrix framework defining a network of pores or cell openings therein, a flexible hydrophilic polymer foam or fiber matrix, An additive or powder pharmaceutical ingredient, including an additive selected from an antibacterial additive, a wound care additive, and a wound dressing additive, a composite of matrix components is provided, the material or the powder pharmaceutical additionally includes a fluidizing agent and / or a bulking agent and / or a binder, The additive and the fluidizing agent and / or the bulking agent and / or the binder are arranged together, or the powder pharmaceutical ingredient is arranged together on one or both of the release surfaces or in the cell network.

[0069] The additives and fluidizing agents and / or bulking agents and / or binders arranged together can be verified by secondary electrons (topography) and backscattered electrons, as illustrated, for example, in FIGS. 3g and 3h by SEM.

[0070] The additive and / or the fluidizing agent are partially embedded and retained in the surface or surfaces and in the cells by the bulking agent and / or the binder that are melt-softened and arranged together.

[0071] In a further aspect, Providing a flexible hydrophilic polymer foam or fiber matrix component including two matrix surfaces providing a release surface and a back surface, or two release surfaces, and therebetween, a network of cells having a cell network surface and a structural matrix framework defining a network of pores or cell openings therein, Providing a powder pharmaceutical ingredient including an antibacterial additive, the additive being an antibacterial species release additive, Contacting the powder pharmaceutical ingredient with the matrix component, A method for producing an antibacterial material is provided, which includes directing the powder charge towards one or both of the surfaces or the release surface, and / or within the cell network, preferably proximal to the surface or the plurality of surfaces.

[0072] In a further aspect, providing a flexible hydrophilic polymer foam or fiber matrix component including a front and back surface facing a wound, or two surfaces facing wounds, and therebetween a network of cells having a cell network surface and a structural matrix framework defining a network of pores or cell openings therein; providing a powder charge component including a wound dressing additive or a combination thereof, wherein the matrix provides a meandering pore network; contacting the powder charge component with the matrix component; A method for producing a wound care material is provided, which includes directing the powder charge towards the surface facing the wound or the back surface and within the cell network in the cells proximal to the surface, more specifically, decreasing in amount as the depth within the network increases.

[0073] The method is preferably a method for producing an antibacterial material or a wound care material as defined above or below, and more preferably a method for producing a material including assembling a composite of the matrix component and the powder charge as defined above and below.

[0074] The method may include, in a previous, simultaneous, or subsequent step, melting and softening of the matrix, and / or of the fluid-permeable laminated net lay-up on the surface, and / or of the binder provided with the powder charge as defined above. The melting and softening embeds or binds the powder charge at the matrix surface and / or within the cell network. The additive is arranged with the melted and softened binder.

[0075] The degree of softening or net lamination or the amount of binder may determine the depth or degree of embedding or binding.

[0076] Providing the powder charge as defined herein involves the selection of the amounts of each of them provided in the powder charge for contact and orientation as defined, in view of its solubility, and additives in view of any fluidizing agent, extender and binder as defined above, and additive particle size and its required availability.

[0077] The available first additive is available for first contact with fluid at the site and rapid diffusion of the antibacterial species to the site, and rapid absorption of fluid from the site or other wound dressing properties. The available second additive is available for second contact with fluid gradually absorbed into the cell network from the site and diffusion of the antibacterial species to the site, for example, through the cell network.

[0078] In embodiments, providing a matrix component in the methods herein involves providing a matrix having a background content or supplementary content of the same or different additives contained within the structural matrix framework. Such background content additives are available for third contact with fluid gradually absorbed from the site within the cell network and thus within the structural matrix framework, and for diffusion of the antibacterial species to the site through the cell network.

[0079] Preferably, the method comprises providing the matrix component or intermediate surface in a desired orientation, such as horizontally or inclined upwardly or downwardly with respect to the administration surface, with a vertically facing orientation also contemplated, providing the aforementioned powder charge within one or more powder charge containers such as hoppers, canisters, cassettes, nozzles, discharge buckets, drums and such containers, Directing the powder charge either directly onto the matrix surface or indirectly onto the intermediate surface, and then bringing the matrix surface into contact with any such intermediate surface, Administering is selected from dusting, powder spreading, powder spraying, powder injection, incorporation, and deposition onto the surface or surfaces.

[0080] Many forms of containers are known, such as those provided on a carousel or conveyor. Discharge buckets include inverted buckets on an inverted carousel or conveyor, hinged buckets, and hopper buckets.

[0081] The intermediate surface may include a release liner for administration and any transient adhesive powder charge thereon, or a gravure for removably containing the powder charge.

[0082] Directing towards both sides of the matrix surface may be simultaneous or sequential by one or more of the direct or indirect administration methods. The resulting material may be asymmetric or preferably symmetric.

[0083] Administering may be continuous or discontinuous in terms of the volume or weight of the powder charge per matrix surface, or per unit surface area of the matrix surface, or per unit volume of the matrix. Administering includes administering to the surface of a partially formed matrix that is still sticky, or casting the matrix onto an administered release liner.

[0084] In an embodiment, the method includes, in a preceding step, preparing the powder charge including selecting, in view of the additive particle size within the materials of the present specification and its required availability, the additive or combination thereof as defined above, and any fluidizing agent, extender and / or binder, and their respective amounts, combining with any blend or mixture, and providing in the powder charge and any extender and / or binder provided therewith for contacting and orienting as defined.

[0085] In an embodiment, the step of preparing the powder charge further includes subjecting the additive or the powder charge additionally to a particle size selection or reduction process. The particle size selection may include sieving, centrifugal or cyclone mass separation, or separating a desired particle size or mass fraction from commercially available powders. The particle size reduction process may be selected according to the required first or second particle size, or the particle size distribution of the additive or powder charge or its components. The first particle size reduction techniques include known bottom-up techniques for controlled particle size recrystallization and top-down techniques such as grinding or polishing. The second particle size reduction techniques include top-down techniques such as grinding or milling for deagglomerating or disintegrating the additive or powder charge.

[0086] In an embodiment, the method of the present specification includes atomizing the additive or powder charge. Atomization may include, for example, using self-collision or collision with other solid particles, such as high-speed air injection and high-speed nitrogen injection, as further described in co-pending UK Provisional Patent Application No. 1711179.0 filed on July 12, 2017, including high-speed injection of an inert gas into the additive, a comminution medium selected from a gas and a particle medium, and a turbulent bed of, for example, high-density microbeads into which the additive is directed, or use of high-density comminution beads or balls such as microbeads directed at the additive, such as injection of the microbeads, and may include dry powder collisions.

[0087] Examples of known drying and pulverizing apparatuses and methods using a high-speed gas injection pulverizing medium include the Dietrich Engineering Consulting (DEC) Conika drying mill, the IKA Pilotina MC drying mill and MC jet mill, and the Food Pharma Systems (FPS) spiral jet mill.

[0088] Preferably, administering the powder charge as defined above to one of the surfaces and into the cell network, and applying a translational force simultaneously or thereafter, thereby causing at least a portion thereof to translate within the cell network.

[0089] The translational movement can be the distance between the surfaces. Alternatively, the translational movement may extend across the entire matrix including the other surface. The resulting material can be asymmetric or symmetric.

[0090] The translational force includes physical forces directly applied to the powder charge, such as needling, or indirectly applied to the powder charge through the matrix, for example, by mangling or rolling the matrix, thereby displacing the powder charge by translational movement due to gravity or suction.

[0091] Alternatively, the translational force includes a field applied to the entire matrix to which the powder charge is administered or is to be administered, more specifically, a fluidization field that fluidizes the powder charge or is arranged such that the powder charge takes a fluid such as a flow. The field includes an alternating electrostatic field (AC electric field), a sound field, an ultrasonic field, an aeraulic field, an air field, etc.

[0092] The translational force can be adjusted for a given powder charge particle size, matrix porosity, etc. in such a way as to manipulate the depth of translational movement within the cell network.

[0093] In an embodiment, the method of the present specification further comprises, in a further step, differentiating, for each respective first availability and second availability, a part of the powder charge contained in the face and a part of the powder charge contained within the cell network in such a way that their respective amounts and the depth at which the second available part is directed within the cell network and / or towards the back or second release face.

[0094] Applying the administration and translational force may be sequential or simultaneous, for example, air injection of the powder charge onto the matrix face with a certain amount of simultaneous or translational movement thereof within the cell network.

[0095] In a further aspect, an antibacterial material or wound care material obtained or obtainable according to the present specification is provided.

[0096] In a further aspect, there is provided an antibacterial device which is applied to a site and is activated by contact with an aqueous medium provided at the site, the device comprising (a) a site contact surface or layer and / or (b) together with an opposing non-site contact surface or layer, (c) an aqueous medium absorption layer contained between and / or in combination with (a) and / or (b), where (c) contains an antibacterial material as defined herein.

[0097] In a further aspect, there is provided a device comprising a wound dressing or a part thereof which is applied to a wound site, such as wound exudate, and is activated by contact with a fluid at the wound site, the wound dressing comprising (a) a wound contact surface or layer and / or (b) together with an opposing non-wound contact surface or layer, (c) one or more optional fluid absorption layers contained between and / or in combination with one of them between them, where (c) contains an antibacterial material or wound care material as defined herein.

[0098] The layer or surface (a) may be an adhesive or a non - adhesive, for example, a film having a conforming elastic gap.

[0099] The layer or surface (b) may advantageously be a breathable top film that enables fluid and air regulation at the site and provides an antibacterial barrier, and is preferably a continuous vapor - permeable conforming polymer film. The layer (b) may include a boundary around the periphery of the material (c).

[0100] The device may include additional layers selected from a masking layer (b') included between the layer (b) and the layer (c), a superabsorbent layer (b'') included between the layer (b) and the layer (c), etc.

[0101] The layers may be laminated and / or sealed within a pouch formed by the outer layer in a relationship having a continuous and uniform spread.

[0102] The materials or devices herein may be sterilized, terminally sterilized and / or moisture - sealed and / or microbe - impermeable packaging such as a silver foil pouch.

[0103] In a further aspect, a method of manufacturing the device herein is provided.

[0104] In an embodiment, the previously formed individual layers may be formed into a laminate by joining the layers together in one or more lamination processes. Suitable joining methods include heat - sealing or adhesive bonding, and the adhesive layer is vapor - permeable.

[0105] In an alternative embodiment, the foam layer is formed in contact with one or both of the other layer or additional layers. This process can be advantageous as it reduces or eliminates the number of special joining operations.

[0106] In another preferred process, a conforming outer film layer is formed on the foam layer, for example, by spraying a solution of a polymer.

[0107] In a continuous process, the wound dressing may be made in the form of a continuous strip, which is then cut into dressings of appropriate size.

[0108] Typically, joining the layers can be a lamination process.

[0109] In a preferred process for forming a dressing in which a foam layer is produced in contact with an outer layer, it is important to laminate another outer layer onto the foam while the foam is still tacky in order to obtain a good bond. Typically, it is preferred to bring the foam into contact with the other outer layer 2.5 to 5 minutes, for example 3 to 3.5 minutes, after the foam has been cast.

[0110] In a further aspect, there is provided a method of treating a site to make or keep the site free of microorganisms harmful to the health of the site, which comprises bringing the site into contact with an antibacterial material or device as defined herein, thereby enabling antibacterial species to be released to the material and / or the site. Such methods are preferably methods of treating a wound site, thereby enabling antibacterial species to be released to the wound site. Advantageously, the antibacterial materials and devices herein release antibacterial species, particularly silver ions, at high concentrations and at high rates, and the release persists for a required period, for example up to 7, 8, or 10 days or more.

[0111] In a further embodiment, there is provided a method for wound care comprising bringing the wound site into contact with a wound care material or device as defined herein.

[0112] In another aspect, there is provided a method of treating a wound. The method comprises placing a loaded wound dressing layer in or on the wound, the loaded wound dressing layer comprising a porous matrix and a powdered charge of an antibacterial release additive loaded within the matrix, the powdered charge being concentrated at least on the surface of the porous matrix facing the wound, and the antibacterial release additive being activated to release an antibacterial agent from the wound dressing to the wound upon contact with a wet or aqueous medium.

[0113] In some embodiments, the method further comprises releasing the antibacterial agent for longer than one day. In some embodiments, the method further comprises releasing the antibacterial agent releasing agent at a maximum of 1.8 mg / cm per day 2 In some embodiments, the method further comprises contacting the wound exudate-loaded wound dressing layer before releasing at least a portion of the antibacterial agent towards the wound, wherein the antibacterial agent is configured to diffuse into the wound exudate upon contact with the wound exudate. In some embodiments, the method further comprises applying a negative pressure to the wound dressing. The antibacterial release additive may be selected from the group consisting of silver element, silver salts, silver complexes, their cage forms, cage forms of iodine, and combinations thereof. The antibacterial release additive may be selected from the group consisting of silver sulfadiazine, silver zeolite, silver sulfate, silver carbonate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate, cadexomer iodine, copper salts and complexes, zinc salts and complexes, gold salts and complexes, chlorhexidine gluconate, polyhexamethylene biguanide hydrochloride, and combinations thereof. In one embodiment, the antibacterial release additive may be selected from the group consisting of silver sulfadiazine, silver zeolite, silver sulfate, silver carbonate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate, cadexomer iodine, and combinations thereof. The antibacterial agent may contain silver ions and / or iodine. In some embodiments, the powder charge of the antibacterial additive further comprises a superabsorbent polymer. The powder charge of the antibacterial release additive may have a particle size of about 1 micron < D90 < 30 microns and D50 < 10 microns. The powder charge of the antibacterial additive may further comprise a fluidizing agent selected from the group consisting of stearates, clays, silica, carbon, graphite, and combinations thereof, wherein the fluidizing agent has a particle size smaller than that of the antibacterial release additive. In some embodiments, the wound dressing further comprises an absorption layer that absorbs the wound exudate and / or a wound contact layer that is disposed in contact with the wound under the loaded wound dressing layer.

[0114] In some embodiments, the wound dressing may further include, instead of or in addition to the antimicrobial release additive, one or more active ingredients. The active ingredients can include, for example, powdered growth factors and small active organic molecules (useful for debriding agents, such as collagenase, or for promoting the healing response, such as MMP inhibitors), local oxygen delivery compounds (e.g., variants of hemoglobin), and any other organic or inorganic bacteriostatic, antibacterial, preservative, or antimicrobial agent.

[0115] When the disclosed technology is in the form of a slurry, the active ingredients, e.g., the active ingredients in the slurry, may exclude growth factors, MMP inhibitors, collagenase, and hemoglobin variants.

[0116] In another aspect, a wound dressing is provided. The wound dressing is a loaded wound dressing, including a porous matrix including a front face and a back face facing the wound, and a powder charge of an antimicrobial release additive loaded within the matrix, wherein the powder charge decreases in amount as the distance from at least the front face facing the wound increases.

[0117] In some embodiments, the matrix includes a polymer foam, a fibrous matrix, and / or a hydrophilic polymer. The antimicrobial release additive can include elemental silver, silver salts, silver complexes, their caged forms, caged forms of iodine, and combinations thereof. The antimicrobial release additive can be selected from the group consisting of silver sulfadiazine, silver zeolite, silver sulfate, silver carbonate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate, cadexomer iodine, and combinations thereof. The antimicrobial release additive is 1.4 mg / cm 2 ~4 mg / cm 2It can be the amount of. In some embodiments, the wound dressing may further include a wound contact layer under the loaded wound dressing layer, a cover layer over the loaded wound dressing layer, a fluid connector configured to connect the cover layer to a negative pressure source, and / or an absorption layer over the loaded wound dressing layer. The absorption layer may include superabsorbent particles. In some embodiments, the powder charge further includes a superabsorbent polymer. In some embodiments, the powder charge of the antibacterial release additive may have a particle size of about 1 micron < D90 < 30 microns ~ D50 < 10 microns. In some embodiments, the powder charge may further include a lubricant selected from stearates, clays, silica, carbon, graphite, and combinations thereof, where the lubricant has a particle size less than that of the antibacterial release additive. In some embodiments, the matrix includes a plurality of cells, and the antibacterial release additive is at least partially embedded within the cells.

[0118] Variations and modifications of these embodiments may occur to those skilled in the art after reviewing the present disclosure. The foregoing features and aspects may be implemented in any combination and sub-combination (including multiple dependent combinations and sub-combinations) with one or more other features described herein. The various features described or illustrated above, including any of its components, may be combined or integrated into other systems. Additionally, certain features may be omitted or not implemented.

[0119] Further areas of applicability of the devices and methods of the present disclosure will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples, while indicating specific embodiments, are intended for purposes of illustration only and are not intended to limit either the scope of the present disclosure or the scope of the claims that may be pursued.

Brief Description of the Drawings

[0120] The foregoing and other objects and advantages will be more fully understood upon consideration of the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals refer to like parts. It is to be understood that the illustrated embodiments are by way of example and are in no way limiting.

[0121]

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DETAILED DESCRIPTION OF THE INVENTION

[0122] The embodiments disclosed herein relate to devices and methods for treating wounds with or without negative pressure, optionally including a negative pressure source and wound dressing components and devices. Devices and components that include materials for covering and packing wounds may be collectively referred to herein as dressings in some cases.

[0123] The preferred embodiments disclosed herein relate to wound therapy for the human or animal body. Accordingly, any reference to a wound herein can refer to a wound on the human or animal body, and any reference to a body herein can refer to the human or animal body. The term "wound" as used herein, in addition to having its broad ordinary meaning, includes any part of a patient's body that may be treated using negative pressure. The term wound is broadly interpreted and includes open and closed wounds where the skin is lacerated, incised, or perforated, or bruised by trauma, or any other surface or other condition or defect in the patient's skin, or any other that may benefit from negative pressure therapy. Thus, a wound is broadly defined as any area of tissue damage where fluid may or may not be produced. Examples of such wounds include, but are not limited to, abdominal wounds, or other large or incisional wounds as a result of any of surgery, trauma, sternotomy, fasciotomy, or other conditions, laceration wounds, acute wounds, chronic wounds, subacute wounds and laceration wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, stomas, surgical wounds, traumatic ulcers and venous ulcers.

[0124] As used herein, a chronic wound is a wound that does not heal in the predictable time within which most wounds heal in an orderly series of stages, and wounds that do not heal within three months are often considered chronic. For example, chronic wounds can include ulcers such as diabetic ulcers, pressure ulcers (or pressure injuries), or venous ulcers.

[0125] The treatment of such wounds can be carried out using negative pressure wound therapy, and a reduced pressure or negative pressure can be applied to the wound to facilitate and promote wound healing. It will also be understood that the wound dressings and methods disclosed herein may be applied to other parts of the body and are not necessarily limited to the treatment of wounds. Other embodiments do not utilize negative pressure for the treatment of wounds or other parts of the body.

[0126] The materials or matrix components defined herein are fluid absorbents, more specifically, absorbents for aqueous fluids such as body fluids, e.g., wound fluids, and their components. The materials or matrix components are liquid, gas, and vapor permeable, e.g., permeable to the aqueous fluid, moisture, and air. The materials serve to regulate moisture and air circulation at the site when applied to the site. The materials provide a moist environment such as a moist wound environment. Preferred materials or matrix components are hydrocellular, i.e., characterized by their ability to create a moist environment and absorb large amounts of fluid. Hydrocellular wound dressing materials are characterized by their ability to create a moist wound healing environment and absorb large amounts of exudate.

[0127] The materials or matrix components herein are continuous or discontinuous bodies shaped into blocks, layers, slabs, mattresses, sheets, strips, webs, or rolls thereof, etc., of regular or irregular shape, or cast. The materials and matrices herein are non-particulate.

[0128] The flexible materials or matrices herein are mutually compatible and elastically stretchable. The flexible materials or matrices herein can conform, for example, to surfaces shaped irregularly or regularly, statically or movably. For example, the materials or matrices conform to the surface of a body part or a wound surface, etc., and dynamically conform to changes due to movement, frictional resistance, stretching, bending, etc. Such materials or matrices can achieve and retain a shape or profile with or without the use of an adhesive or other restraint.

[0129] The materials herein are preferably selected from microorganisms, yeasts, and fungi, and are therefore used to inhibit or kill microorganisms selected from, among others, antifungal, antibacterial, anti-yeast, and in particular, bactericides, germicides, bacteriostatics, and / or bacteriostatics and combinations. To avoid doubt, the antibacterial species-releasing additives herein are outside the class of antibiotics of antibacterial agents.

[0130] The antimicrobial material is expected to come into contact with an aqueous medium such as an aqueous fluid such as body fluids such as waste liquid, contaminated fluid, and wound fluid at the site. Particularly preferred sites are moist.

[0131] The antimicrobial material can be a medical material such as a wound care material, a dental material, a personal care material, a hygiene or public health material such as a clothing material, a decorative material, a food industry material, a packaging material, etc. The material may be used directly or contained within a device.

[0132] Thus, for example, silver salts and / or wound care additives that are advantageous for wound dressings are combined as a dry powder with a porous matrix useful for wound dressings. The resulting material composite can then be used in the manufacture of wound care devices such as wound dressings for application to wet wound sites that do or do not exude.

[0133] In an embodiment, the material applied to the wound site absorbs exudate and particulate matter from the surface of the granulating wound, and as the material becomes wet, antimicrobial species such as ionic silver or diatomic and ionic iodine species are released. Thus, the material has the dual effect of cleaning the wound and performing an antibacterial action.

[0134] Advantageously, the asymmetric antimicrobial material of the present specification is adapted to bring the site at risk of microbial infection into contact with the matrix release surface, i.e., the side of the material proximal to the site that is rich in the antimicrobial agent, such that the maximum amount of antimicrobial additive is nearby and most readily available where needed.

[0135] Advantageously, the asymmetric wound care material of the present specification is adapted to bring the wound into contact with the side of the material proximal to the wound that is rich in the additive, or the side facing the wound that may be poor in the additive, such that the additive is located where needed.

[0136] Advantageously, the symmetric antimicrobial or wound care material presents a choice of the side facing the site or wound, i.e., the material is not hand-processed and the site is adapted to be processed directly or within a device to contact the release surface or the additive-rich side of the material proximal to the site or wound.

[0137] Figures 1a - 1h and 1j illustrate variations of the symmetric materials of the present specification that contain powder charges on both sides of the matrix surface and within the matrix cell network. The additive may not be present on the surface or surfaces, which may interfere with adhesion within a layered device that includes additional layers or at a site such as a wound. The matrix can be treated to prevent loading of the powder charge on the surface or surfaces, for example, by removing a thin surface layer from the matrix or selecting a slice of the matrix that omits the matrix surface. Variations with or without surface-loaded additives can include: a) a uniform low concentration within the cell network proximal to the surface, e.g., within a few cells from each surface; b) a uniform high concentration within the cell network proximal to the surface, e.g., within a few cells from each surface; c) and d) a concentration that decreases from high to low within the cell network proximal to the surface, e.g., within a few cells from each surface, where in case c) it is a short depth to the intermediate cell network and in case d) it is to an intermediate depth; e) a uniform high concentration within the cell network proximal to the surface up to a short depth to the intermediate matrix from each surface; g) a low concentration throughout the cell network; h) a high concentration throughout the cell network. i) illustrates a symmetric variation that contains powder charges on only both sides. j) and k) illustrate the variations of 3b) and 3i), and the matrix components prior to assembly contain a background content of additives such as the same or different antimicrobial additives contained within the matrix structural framework.

[0138] Figure 2 illustrates cross-sectional SEMs of matrix cells and pore network architectures that a) provide the meandering pore network of the present specification, b) provide the reticulated cell network or pore network of the present specification, and c) provide the meandering pore network of the present specification. Matrix types a) and c) may provide the asymmetric materials of the present specification having powder charges loaded asymmetrically or with reduced concentration within the cell network of the present specification. Matrix type b) may provide the symmetric materials of the present specification having powder charges loaded symmetrically within the cell network of the present specification. Both matrix types may provide symmetric or asymmetric materials loaded on the surface or the plurality of surfaces.

[0139] Figure 3a is a cross-sectional SEM of a conventional polyurethane foam at the time of manufacture containing silver sulfate (bright spots) provided in the aqueous phase of the polymerization reaction and contained across the structural polyurethane framework.

[0140] Figures 3b and 3c illustrate the antibacterial polyurethane foam matrix of the present specification that provides a meandering pore network and contains a powder charge of silver sulfate (bright spots) on the foam surface and within the cell network. It can be seen that the powder charge is concentrated proximal to the matrix surface where the charge is administered. There is penetration of silver sulfate concentrated within the cell network at a maximum depth of 1 mm in the 2 mm thick foam and (3c) foam / fiber laminate. There are some silver salt particles present deep within the structure, which are associated with the concentration proximal to the administration and release surfaces.

[0141] Figures 4a - 4o illustrate the asymmetric material deformations of the present specification. Figures 4a - 4h, j and l illustrate asymmetric deformations including powder charges on one matrix face and within the cell network, where there may be no additives on this face or these faces, in which case this interferes with adhesion in a layered device having additional layers or at a site such as a wound as explained above in the context of Figure 1. Deformations with or without surface - loaded additives are: a) a uniform low concentration from the face to a small cell depth within the cell network proximal to the release face; b) a uniform high concentration from each face to a small cell within the cell network proximal to the face; c) a concentration decreasing from high to low from the face to a small cell within the cell network proximal to the face; d) a uniform low concentration from the face to the matrix intermediate depth within the cell network proximal to the release face; e) a uniform high concentration from the face to the matrix intermediate depth within the cell network proximal to the face; f) a concentration decreasing from high to low from the face to the matrix intermediate depth within the cell network proximal to the face; g) a high concentration to the face within the cell network proximal to the face and a high concentration to the back face from the rest of the entire cell network; h) a high concentration from within the cell network to the matrix intermediate depth and a low concentration from the rest of the entire cell network to the back face. 4) and k) illustrate asymmetric deformations including only powder charges on the face. 4j) and k) illustrate the deformations of 2b) and 2i), and the matrix components before assembly include the background content of additives such as the same or different additives contained within the matrix structural framework. Figure 4l illustrates deformation 4a) including powder charges on both faces of the face and within the cell network proximal to one of the faces.

[0142] The materials of this specification may have powder charges within the cell network proximal to the surface, at any desired depth from the surface, for example, from two average cell diameters to an intermediate matrix depth or a full matrix depth, such as 5% - 50% or 85% or 100% (10% or 20% - 50% or 85% or 100%) of the cell network depth or matrix depth, or at a depth of 1 mm or 2 mm or 3 mm - 6 mm or 7 mm or 1 cm of the material or matrix with a separation of 0.2 mm or 0.3 mm or 0.4 mm or 0.5 mm - 1 mm or 2 mm or 3 mm or 4 mm from each surface, that is, a separation of 1 mm or 2 mm or 3 mm - 6 mm or 7 mm or 1 cm from each surface, or at a depth of 1 cm - 4 cm of the material or matrix with a separation of 0.5 mm or 1 cm - 2 cm, that is, a separation of 1 cm - 4 cm from each surface.

[0143] The materials of this specification may be post - assembly adjusted, such as by drying, equilibration, storage or packaging, sterilization, etc., with no or an incidental effect on the powder charge or additive properties, such as its release profile. Thus, advantageously, the antibacterial materials of this specification may be adjusted, for example, sterilized, using a release profile corresponding to a non - sterilized pre - assembly powder charge. Therefore, when such effects exist, they may be considered when determining the amount of the powder charge, its administration and / or orientation.

[0144] The materials of this specification may be sterile or non - sterile, preferably finally sterile or non - finally sterile, and may be sterilized, for example, by steam, gamma radiation, X - rays or electron beams or ethylene oxide. As shown in Figure 9, the ionic silver release is equivalent in matching samples of a material composite assembled from the same powder charge and the same matrix, where one is sterile and the other is sterilized with ethylene oxide.

[0145] The materials in this specification preferably have a water content of less than 10% (by weight), more preferably less than 8% (by weight), and most preferably less than 5% (by weight). The additives or powder charges in this specification typically have a weight loss on drying of 0.5% by weight or less (such as 0.4% by weight or 0.3% by weight or less) before and after loading into the matrix of this specification when dried in a vacuum oven at 50 °C for 4 hours.

[0146] The matrix component of this specification can have a thickness of 0.5 mm to 20 mm, more preferably 0.8 mm to 15 mm, preferably 1 mm to 12 mm, for example, 2 mm, 3 mm, 4 mm, 5 mm or 6 mm, but can be of a lesser or greater thickness as required.

[0147] The matrix component can have a cell size of 30 microns to 1000 microns (such as 30 microns to 700 microns or 300 microns to 1000 microns). The porous foam matrix component of this specification preferably has a particle size in the range of 50 microns to 500 microns in average diameter, for example, 200 microns to 250 microns.

[0148] The matrix of the present specification can have 20% to 70% of the total surface area of the cells as openings. The matrix can be, for example, about 70% to 90%, a very high free internal volume. The matrix can have a desired cell network and pore network architecture. The microstructure of the polyurethane (PU) foam ranges from a foam having small circular holes at the center of the pore surface, which provides air flow resistance across the foam, as shown in, for example, FIG. 2a, to a reticulated and low-density "open" foam, as shown in, for example, FIG. 2b, in which no pore surface remains, providing free air flow across the foam. The corresponding fiber matrix ranges from a matrix that includes misaligned voids, cells, and misaligned pores interconnecting the voids between the fibers, which provides air flow resistance across the matrix, to a matrix that includes aligned voids between the fibers and aligned pores interconnecting the voids, which provides free air flow across the matrix. The matrix of the present specification can be characterized by the air resistance between its surfaces as a function of elements such as the size of the pores in the cell surface, their orientation and spacing, the cell size, and the proportion of the cell surface that includes pores, including cell network and / or pore network meandering. The air flow resistance of the PU foam is thought to be a function of the area of the largest pores in the cell and the area of the linked paths between the large pores.

[0149] In an embodiment, a material containing an additive on the matrix surface and within its cell network includes high air flow resistance between the surfaces and / or low air permeability and / or a highly meandering pore network, where the material is asymmetric as defined above. The highly meandering polymer foam or fiber matrix of the present specification is preferably selected from hydrocellular polymer foams and fiber matrices intended for use in wound care applications, more preferably selected from polyurethane foams and their combinations, superabsorbent fiber fleeces, cellulose fiber fleeces, etc.

[0150] Such matrix components may be commercially available or may be manufactured by techniques known in the art, and all are commercially available from Smith & Nephew, Inc., including TENCELTM fiber (DurafiberTM), polyurethane foam matrix (AllevynTM and Allevyn AgTM), cellulose matrix (Post-opTM), woven cotton gauze fiber (BactigrasTM), absorbent rayon / polyester matrix (ActicoatTM), and MepilexR and MepilexR Ag available from Moelnlycke Health Care. Fiber matrices such as cellulose superabsorbent airlaid are commercially available (Glatfelter).

[0151] The matrix components may include combinations of fibers and foams, such as combinations of the above commercially available fibers and foam matrices, such as superabsorbent fibers, or commercially available combinations such as MepilexR Border (and Ag) that include a laminated bilayer of polyurethane foam and superabsorbent fibers.

[0152] The polyurethane foam matrix component may be manufactured as disclosed, for example, in EP0059049 and EP1964580, both of which disclose the option of incorporating an antibacterial agent into the original foam prior to polymerization. The polyurethane foam component can be produced by reacting a hydrophilic isocyanate-terminated polyether prepolymer with water, an aqueous liquid or an aqueous surfactant, casting it into a mold or liner such as a molding liner, and optionally drying it. The matrix component may be the final product, or it may be a semi-finished product that is pre-mixed and cast into a mold or liner that is administered the powder charge as defined above in situ in the method of the present specification. The highly tortuous pore network polyurethane foam of the present specification can be produced, for example, by mixing 100 parts by weight of an isocyanate such as Hypol FHP2000, 2001, 3000, 3001, 2002 or 2000HD, 0.3 to 7 parts by weight of a surfactant or a mixture of surfactants, and 30 to 300 parts by weight of water and a foam mixture cast on the surface. A typical foam mixture has a cream time of about 20 seconds, a rise time of about 250 seconds, and a cure time of about 400 seconds.

[0153] The silver ion releasing additive is preferably in an amount of 0.05 mg to 3.5 mg, or 0.05 mg to 4 mg of silver ions / cm of the material as defined herein 2 (0.1 mg to 3.5 mg or 4 mg of silver ions / cm as defined herein 2 or 0.2 mg to 3.5 mg or 4 mg of silver ions / cm as defined herein 2 etc.) and is included in the material of the present specification or assembled with the matrix component of the present specification. The material may contain an additive such as silver sulfate in an amount ranging from 1.75 mg / cm 2 to 3.5 mg / cm 2 , for example in the range of 1.4 mg / cm 2 up to a maximum of 4 mg / cm2 exceeding.

[0154] The antimicrobial additive is preferably characterized by a species release profile, i.e., the amount of the species defined above released over time, such as the release amount in 50 mL of an aqueous medium obtained as mg of material per unit of time known in the art. In an embodiment, the release profile is a rapid start within 24 hours, i.e., a bolus release, followed by a second release in a steady state that lasts for up to 10 days, for example, up to 7 - 8 days.

[0155] The antimicrobial additive can provide the minimum bactericidal concentration (MBC) or minimum inhibitory concentration (MIC) of the antimicrobial agent during the life of the material or at specific time intervals from startup. The MBC is a measure of the concentration of a given antimicrobial species in a given fluid, obtained as mg of species / mL of fluid.

[0156] For example, the MBC can be 0.4 mg - 50 mg of silver ions / 50 mL of wound fluid or simulated wound fluid or aqueous medium, or 0.7 mg - 2 mg of iodine / mL, depending on the microorganism, the selected medium, the test setup, and the ease of killing.

[0157] Release can be obtained with a material containing a silver salt that provides an equivalent antimicrobial material calculated as mg salt / cm for a given material having a given absorption with respect to, for example, thickness, etc. 2 The MBC is preferably reached as quickly as possible and exceeded.

[0158] The method for determining ion release is, for example, by ASTM E2149 (Microbiological Examination) with modifications known in the art. ASTM E2149 enables the evaluation of many different types of materials and devices, and a wide range of microorganisms. The materials and devices are subject to a wide range of physical / chemical stresses or operations, and the test allows for the diversity of testing the effects of contamination caused by hard water, proteins, blood, serum, various chemicals, and other contaminants.

[0159] The powder charge of the present specification is commercially available and may be included as provided in the powder charge, or may be processed, for example, by drying, by reducing the particle size such as the selection of its desired particle size grade, or by methods known in the art, and includes the additives of the present specification.

[0160] In embodiments of the present specification, the powder charge or additive has a loss on drying (L.O.D) of less than 2%.

[0161] The L.O.D is preferably determined in a sample of the powder charge or additive of the present specification as a weight loss of less than 2% (e.g., less than 1%) or less than 0.5% (e.g., less than 0.4%), or less than 0.3% (e.g., less than 0.2% or 0.1%) during 4 hours in a vacuum oven at 50 °C or a non-vacuum oven at 105 °C.

[0162] The defined L.O.D allows for the accurate dosing of the additive or its powder charge without the need for additional or variable water content in the dosed amount.

[0163] The L.O.D can be determined as the powder charge or additive. Alternatively, the L.O.D may be determined as a material containing the additive and includes wet losses from the matrix and from the additive. The material humidity varies depending on atmospheric conditions and can be determined and separated in a suitable manner.

[0164] Preferably, the powder charge contains additives having a particle size and its distribution that are compatible with the matrix components and manufacturing requirements, such as the matrix component cell size, pore size, and dosing requirements. The particle size of highly soluble salts such as silver nitrate may be selected for compatibility with manufacturing requirements such as matrix cell and pore size and dosing, and can be, for example, about 50 - 1000 microns, such as 50 - 200 microns (such as 100 microns), compatible with a 200 - micron cell size matrix. The additives for filling the matrix herein may have a particle size distribution of about 8 microns < D90 < 115 microns, or 4 microns < D50 < 60 microns, or 1 micron < D90 < 30 microns. Certain advantageous additives have a particle size distribution with D50 < 10 microns.

[0165] The additives can be provided with any suitable particle size and particle size distribution by size reduction to a suitable micronization that is commercially available as the supplied additive, or known in the art, or by a novel method disclosed in the unpublished U.S. Provisional Patent Application No. 1711179.0 filed on July 12, 2017, which is concurrently pending and the content of which is incorporated herein by reference.

[0166] The additives are preferably micronized, and the micronization is by a novel method disclosed in the unpublished U.S. Provisional Patent Application No. 1711179.0 filed on July 12, 2017, which is concurrently pending and the content of which is incorporated herein by reference, and includes, for example, the provision of the additive or powder charge, and its micronization by particle collisions selected from collisions with fluidized solid particles such as gas phase self - collisions and contact with gas or particle grinding forces such as high - speed air injection or high - density grinding beads or micro - beads.

[0167] The powder charge may contain a glidant as defined above selected from clays such as fumed silica, stearates, activated carbon, bentonite, montmorillonite, mica, etc. The glidant is medically compatible.

[0168] The flow agent is provided in the powder charge as defined above as a fine particle size powder in the range defined above for the additive. In the case of the low solubility additive defined above, the flow agent has a particle size of about D50 < 10 microns and is included within the powder charge with a low micron size additive having a particle size distribution of, for example, D50 < 10 microns.

[0169] The flow agent may be present in an amount of up to 20 wt% (0.5 - 8 wt% or 0.5 - 4 wt%, for example 2 wt%). The amount is selected depending on the nature of the selected agent and is selected so as not to reduce the matrix porosity and not to affect the flexure / flexibility when softening.

[0170] The flow agent may provide additional functions. For example, carbon functions as an odor control agent, or as a colorant that masks matrix discoloration in the case of light-sensitive silver salts, or as an absorber of colored aqueous media such as wound fluid, blood. The powder charge may contain a bulking agent selected from inert organic polymers such as PEG. The bulking agent may be present in an amount of up to 80 wt% (such as 10 - 80 wt% or 20 - 80 wt%), or 20 - 80 wt% (for example, 25 wt% or 50 wt%), or 75 wt%. The bulking agent helps to ensure a small change in processing accuracy during administration.

[0171] The bulking agent may have a particle size less than, the same as, or greater than the particle size of the additive in the range defined above for the additive. A particularly useful particle size in the case of the low solubility additive defined above is in the range of 50 - 100 microns, for example 80 microns.

[0172] One or more additional additives may be included in the matrix component as defined herein or within the powder charge, for example, selected from the wound dressing additives as defined above.

[0173] The fluid-permeable laminated net inhibits the additive from dropping off from the materials of the present specification. A suitable laminated net can be a porous polymer sheet or net that is generally used to interact and adhere adjacent layers in a wound dressing material. Extruded polymer meshes, non-woven fabrics or melt-blown fabrics are known, such as polyamides, polyesters, or polyethylene, for example DelnetTM, (registered trademark) Delpore(registered trademark), Stratex(registered trademark) and Naltex(registered trademark)(Delstar).

[0174] The fluid-permeable laminated net can be heat-laminated at a high temperature (such as 150-170 °C).

[0175] Methods for directing the additive towards the surface known in the art as defined above include, for example, i) administering the powder charge to the surface of the matrix, or ii) administering the powder charge to a liner such as a silicone surface or a silicone-coated surface, or to a molten polymer layer, preferably by casting a foam matrix mixture or fiber mixture to contact the cast matrix, applying the cast foam or the fiber matrix on its surface to the liner, or applying the liner to the cast foam or fiber matrix surface.

[0176] For example, a liner providing a powder charge "storage part" and a matrix surface "reception part" are joined in a batch or continuous process, whereby the powder charge moves in contact from the liner to the matrix surface. The liner may be a belt having a thin layer of powder charge thereon, or an adhesive or non-adhesive molten polymer film or laminated net that can be heat-laminated on the matrix surface. The matrix may be a matrix belt or layer.

[0177] The liner can be a continuous liner in the form of a closed-loop conveyor belt, which is arranged on the vertical surface under the hopper, canister or storage part of the powder charge, receives the powder charge from the hopper or storage part, and has pockets that exist alternately in an upright and inverted manner for administering it to the matrix arranged thereunder.

[0178] Preferably, the method uses a belt system or a stamp printing system that uses gravure known in the art, for example, to join two surfaces or to perform transfer coating on a surface. Such methods are known, for example, in the context of organic powder coating for the production of durable coatings such as organic dyes or inorganic sintered materials, for example, for a dry powder coating process.

[0179] The matrix can be newly cast and thereby be sticky, or the powder charge can contain a medically acceptable adhesive powder or a soft sticky gel. Thereby, the powder charge can be reliably held on the surface.

[0180] The matrix can be heated simultaneously with or after the administration of the powder charge to cause melting and softening of a binder optionally contained in the matrix surface or the powder charge, or of a commercially available molten polymer liner or a laminated net placed on the surface as described above.

[0181] For example, the method can include applying heat and / or pressure, such as by contact or by a laminating plate, after the administration defined above and below, to fix the molten polymer liner or the laminated net to the matrix surface.

[0182] Administering the powder charge to the matrix surface i) or to the liner ii) is, for example, by air spraying, spreading, or dusting the dry powder onto the liner or matrix surface. The air spraying, spreading or dusting can be from a hopper, canister or storage of the powder charge. The powder charge may be fluidized or be a fluid flow induced by mixing with air injection or flowing or radiating from a storage such as a hopper.

[0183] The powder charge is administered according to ii) and may be loosely held or supported at the matrix release surface for subsequent or simultaneous translational movement within the cell network as defined above and below.

[0184] Methods for translational movement known in the art or described herein include, for example, administration to a surface and translational movement within the cell network by I) physical forces or II) - V) excitation fields / forces defined above.

[0185] I) For example, mangling or needling by known techniques for forming a matrix by interlocking or meshing non-woven fibers. Preferably, mangling includes applying a roller or other translational force to the release surface, optionally with a liner therebetween or to the back surface. Preferably, needling includes inserting and penetrating one or more fine protrusions into the matrix, thereby causing the powder charge to translate within its cell network.

[0186] II) An aeraulic field, such as air injecting the powder charge onto the matrix surface by a certain amount of simultaneous translational movement within the cell network. The air injection is applied to the surface in the direction of the cell network. The air injection may also be from a hopper, a canister, or a storage section of the powder charge. The powder charge is fluidized by mixing it into the air injection. For example, the supply line to the hopper, canister, or storage section mixes the powder charge with air and injects it from one or more spray heads, which may preferably have an adjustable gap, at the matrix surface. The hopper, canister, or supply line may include a measuring device for measuring a predetermined dosage of the powder charge. The spray gun may be operated automatically or by a robot using a mechanism for injecting at a desired rate across the matrix surface. Alternatively, the air spray may be by dry powder technology known, for example, from US2017 / 098818, the entire content of which is incorporated herein by reference. Air spray devices are available, for example, at Nordson.com.

[0187] III) High-intensity air injection using the air injection technique defined above, operated at an air injection velocity and / or with a contact area sufficient to direct the fluidized powder charge into the cell network. The method preferably includes fluidizing the administered powder charge by a plurality of air injections aligned together or by air injection diffuser heads directed towards a matrix surface. The air injection diffuser head may include a diffusion outlet surface area corresponding to the matrix surface area or a part thereof, and the diffusion head may be aligned facing the matrix surface at a right angle or at an angle thereto with a suitable separation of 1 mm to 5 mm or more. The diffusion head may be recessed within a hood located around the matrix surface or the diffuser head, or may be sealed together with the matrix within a powder charge storage means such as a vacuum back. The vacuum can withdraw the powder charge in the matrix in the case of the reticular symmetric loading of the present specification or in surface loading in the case of a meandering pore network that collapses under the application of the vacuum. Advantageous fluidization by the air injection diffuser enables discretionary turbulence and minimal loss of the powder charge.

[0188] The high-intensity air jet may be provided with a hopper, canister or reservoir for the powder charge, whereby dosing and indication within the matrix are possible simultaneously.

[0189] IV) For example, an alternating electric field that is an alternating electric field force applied across the matrix perpendicular to the surface by an impregnation service provided by, optionally, commercially available Fibroline SA. The method operates two opposed planar electrodes connected to an alternating electrostatic high voltage generator, the electrodes being protected by a dielectric material and spaced apart by a distance suitable to allow a matrix to pass between them. The matrix can be either a continuous matrix such as a roll or a discontinuous section or length of matrix conveyed between the electrodes on a suitable carrier device and passes between the electrodes at a rate exceeding from 10 m / min to 300 m / min. Fibroline's D-Preg, S-Preg or T-Preg methods can be selected according to the scale and dimensions of the required material and the amount and concentration of the powder charge provided thereon. The T-Preg method can be selected for the manufacture of materials containing low powder charge concentrations or using low powder charge volumes. The method is disclosed in US2016 / 0228909, the content of which is incorporated herein by reference.

[0190] U.S. Patent No. US2016 / 0228909 discloses optimizations for achieving deep impregnation of a powder charge across a substrate and illustrates uniform impregnation throughout the thickness of a matrix of powder administered to one surface. Referring to FIGS. 3b and 3c, a powder charge containing silver sulfate is shown as the bottom and top layers in each drawing and is administered to the release surface directed towards the cell network closest to the administration surface. There is some penetration of the salt, but most is within the first 1 mm of a 2 mm thick foam. There is some silver sulfate deep within the matrix, but this is an incidental concentration compared to the silver sulfate within the cell network proximal to the administration surface. This is advantageous in the materials of the present specification containing antibacterial species releasing additives.

[0191] V) An alternative excitation field may be the oscillatory excitation field described in US2016 / 0228909, generated by a series of freely rotating bars instead of electrodes, the bars having a polygonal cross-section and having those diameters selected according to the thickness of the matrix and the forward rate of the matrix entering the field through the field. The aforementioned bars apply a variable pressure to the matrix, generate vibrations therein, fluidize the powder charge administered to its surface, whereby the fluidized charge is directed into the matrix cell network.

[0192] In an embodiment, the fluidization may be by powder excitation in a field selected from the alternating electrostatic field (AC electric field), sound field, ultrasonic field, aeraulic field, air field, etc. as defined above. The method preferably includes administering a powder charge to the matrix surface as defined above and exciting the powder charge by applying an excitation field to the surface. The excitation field is preferably applied perpendicular to the surface. The field may be applied continuously or discontinuously. The continuous field may be applied to the matrix by continuously passing the field as a continuous sheet or roll, or as separate portions.

[0193] The excitation field / field forces such as II) - V) above are preferably applied for a period sufficient to fluidize and translate the powder charge within the cell network of the present specification. The fluidization and translation are rapid. Suitable durations are from 3 seconds to 30 seconds, such as less than 1 minute, for example, 5, 10, 15, 20 or 30 seconds. The excitation field is preferably non-turbulent.

[0194] In a preferred embodiment, a flexible hydrophilic polymer foam or fibrous matrix component, including two matrix surfaces and therebetween a structural matrix framework defining a network of cells having a cell network surface and a pore network, and a powder charge as defined above, for producing an asymmetric material is provided. administering the powder charge to the release surface and applying an excitation field to fluidize the powder charge and direct it into the cell network, the powder charge is contained within the cell network proximal to the release surface with a concentration decreasing as the depth within the cell network increases, and the powder charge is present in an amount associated with the back surface and the cell network proximal to the back surface, characterized in that the matrix provides a meandering pore network.

[0195] The matrix component preferably includes a foam matrix having a superabsorbent fiber matrix laminated on the back surface of the foam matrix, and / or the powder charge preferably includes a superabsorbent polymer together with the antibacterial additive.

[0196] The above-described method preferably includes laminating a molten polymer laminate net on the release surface.

[0197] The materials herein are for use selected from the management of the hygiene and sterilization and in-use sterilization of articles including medical and dental articles, the hygiene and sterilization of personal care products and articles such as napkins, diapers, cosmetics, the hygiene and sterilization of foods or fluids including air and water, or systems for their preparation and production such as food preparation or packaging plants, ventilation systems, water management systems, and such uses are particularly beneficial, especially for preventing or defending against microbial infections.

[0198] The materials can be for application to a wound associated with the presence, contamination, or risk of infection by microorganisms harmful to the wound or the health of the subject, particularly selected from bacteria, yeasts, and fungi and combinations thereof.

[0199] Wound management includes superficial granulation wounds, chronic and acute exudative wounds, full and partial thickness wounds, exudative wounds, infected wounds, septic wounds, malignant wounds, surgically debrided wounds, first and second degree injuries, donor sites, fungating wounds, etc. Wounds for which the materials defined above have a specific use include, for example, ulcers and bedsores such as pressure ulcers, leg ulcers and diabetic leg ulcers, surgical wounds, traumatic wounds, partial thickness burns, wounds at skin flap and skin graft donor sites, tunnel and fistula wounds, wounds left for secondary healing, bleeding-prone wounds such as surgically or mechanically debrided wounds, wound cavities, crater wounds, and open wounds.

[0200] The asymmetric materials of the present specification can be readily utilized for release near the location where the maximum amount of antibacterial species is required, or such that the maximum amount of wound dressing additive is proximal or remote from the wound, such as the wound-facing surface or release surface, such as the additive-rich side, or, for example, the additive-poor side rich in silver, or is useful for providing a choice of silver-rich sides for placement facing a site or wound.

[0201] The materials of the present specification are suitable for defending against Gram-positive bacteria and / or Gram-negative bacteria, such as staphylococci such as Staphylococcus aureus, Staphylococcus epidermidis and MRSA, streptococci, enterococci, coryneform bacteria, and Clostridium difficile, also Gram-positive bacteria selected from the genus Peptostreptococcus, the genus Lactobacillus, the genus Propionibacterium, Bifidobacterium, and the genus Actinomyces, and / or proteobacteria such as Enterobacteriaceae, such as Pseudomonas such as Escherichia coli, Salmonella, Shigella, Pseudomonas aeruginosa, Proteus, Klebsiella, also Legionella, Haemophilus, Neisseria, Acinetobacter such as Acinetobacter baumannii, the genus Bacteroides, the genus Prevotella, the genus Fusobacterium, the genus Porphyromonas, and Gram-negative bacteria selected from cyanobacteria and spirochetes.

[0202] The materials of the present specification are particularly useful for defending against one or more microorganisms encountered in a wound environment, such as Gram-negative bacteria such as Pseudomonas spp., Pseudomonas aeruginosa, Gram-positive bacteria such as Staphylococcus aureus, more specifically MRSA also known as ORSA, anaerobic bacteria such as Bacteroides fragilis, yeasts such as Candida albicans, and fungi such as Candida albicans and Aspergillus.

[0203] The device defined above may be a medical or dental sponge or wipe, or alternatively, in combination with additional functional materials, it is a wound dressing.

[0204] In a preferred device of the present specification, layer (a) and / or (b) is independently selected from silicone, polyurethane, etc.

[0205] The device of the present specification may include the same or different antibacterial or wound care materials defined above provided in a plurality of layers. For example, two or three layers of asymmetric materials may provide additive layers within the device.

[0206] In this embodiment, the device may include materials manufactured in the form of a commercially available wound dressing, such as in the form of dressings in the ALLEVYNTM range, dressings such as OPSITETM and OPSITETM POST-Op Visible, PICOTM, Algisite, DurafiberTM, Mepilex, etc.

[0207] Figure 5 illustrates a wound dressing format incorporating the antimicrobial materials of this specification. Figures 5a and 5b illustrate a dressing comprising the above layers (a), (b) and (c). In Figure 5b, the layers are held together by thermally laminating the outer layers (a) and (c) at their boundaries. Figure 5c shows a variant 5b incorporating the above additional layers (b’) and (b’’). Figure 5d illustrates a variant of Figure 5a incorporating a foam and fiber matrix bilayer. The bilayer may constitute a bilayer antimicrobial material as defined herein, which includes a bilayer matrix component containing the powder charge components as defined herein. Alternatively, the bilayer may constitute separate antimicrobial material layers, either or both of which contain a matrix component containing the powder charge components as defined above.

[0208] The packaged devices herein are preferably packaged in a waterproof pouch such as an aluminum foil pouch.

[0209] In a further aspect, the present specification provides a method of manufacturing the devices described herein.

[0210] In embodiments, the previously formed individual layers may be formed into a laminate by joining the layers together in one or more lamination processes. Suitable joining methods include heat sealing or adhesive bonding, and the adhesive layer is water vapor permeable.

[0211] In alternative embodiments, the foam layer is formed in contact with one or both of the other or additional layers. This process may be advantageous as it reduces or eliminates the number of special joining operations.

[0212] In another preferred process, a conforming outer film layer is formed on the foam layer, for example by spraying a solution of the polymer.

[0213] In a continuous process, the wound dressing can be manufactured in the form of a continuous strip which is then cut into dressings of a suitable size.

[0214] Typically, joining layers can be a lamination process.

[0215] In a preferred formation process of the coating material in which the foam layer is formed in contact with the outer layer, it is important to laminate another outer layer to the foam while the foam is still sticky in order to obtain a good bond. Typically, it is preferable to bring the foam into contact with the other outer layer for 2.5 to 5 minutes, for example, 3 to 3.5 minutes after the foam has been cast.

[0216] The treatment method defined above is for treating sites such as wounds. Suitable sites for treatment are wet or contain an aqueous fluid. Release of the antibacterial species is activated within the site or wound when in contact with moisture or an aqueous fluid. Suitable wounds exude.

[0217] The treatment method of the present specification preferably includes additionally fixing the material or device of the present specification in a fixed position in contact with the site or wound. The means for suitable fixation is robust enough to hold the material or device in a fixed position for a required period, for example, 7, 8 or 10 days or more. Fixation is obtained by adhesion to the site such as the skin surrounding the wound, the site contact surface such as the wound contact surface, or the cover layer or a further adhesive layer or strip or the bandage applied on the material or device.

[0218] Embodiments of the present specification are illustrated below with reference to non-limiting examples thereof.

Examples

[0219] Comparative Example 1: Preparation of a PU foam loaded with silver sulfate at the point of manufacture (P.O.M) Example CE1.1: P.O.M. loading (aqueous) A PU foam sample containing silver sulfate (supplied by Alfa Aesar at 40 - 70 microns) was prepared using a modification of the method of Example 8 of EP0059049 in which the aqueous solution of silver sulfadiazine was replaced with an aqueous solution of silver sulfate.

[0220] Silver sulfate (1.5 g) was mixed with Brij 72 emulsion (30 g as a 2.5% aqueous solution) using a high - speed shear mixer.

[0221] The mixed emulsion additive was added to Hypol 2002 (20 g) in a beaker and mixed using a metal spatula and then mechanical stirring until Hypol was uniformly dispersed (approximately 20 seconds), and cast into a shape liner to produce a foam having an equivalent loading dose (TS) of 1.9 mg / cm2. In the SEM images of the resulting material shown in Figures 2a and 2b, silver sulfate (bright spots) was loaded into the pores across the 2 - mm - thick foam (dark gray relative to the gray cross - sectional structural matrix framework or gray cross - sectional cell surface), indicating the loading of particles sedimented from the solution in sub - micron size.

[0222] Example CE1.2: P.O.M. Loading (aqueous suspension) The PU foam contains silver sulfate loaded into the structural matrix framework from a combined solution suspension of silver sulfate combined in the aqueous phase of the polyurethane foam polymerization reaction, as disclosed in European Patent No. EP1964580.

[0223] Comparative Example 2 Preparation of a multilayer coating composition Example CE1.1D (P.O.M. Loading (aqueous)) The foam of Comparative Example CE1.1 was provided together with the corresponding CE1.1D having a breathable upper film layer and an adhesive wound - contact layer in the form of a multilayer coating composite.

[0224] Example CE1.2D (P.O.M. Loading (aqueous suspension)) The commercially available MepilexR Border Ag (Moelnlycke Health Care) is a multilayer dressing CE1.2D (in the form of Figure 5c) that includes a hydrocellular PU foam produced using the method of Example CE1.2 of silver sulfate (P.O.M. loading (aqueous suspension)), an unknown silver sulfate, a superabsorbent fiber layer, a breathable PU top film, and a weak adhesion wound contact layer having an equivalent loading dose (TS) of 1.3 mg / cm2. The silver sulfate is included as particles from a partially precipitated / partially suspended liquid that consists of a single population of 15-micron particles and a second population of fine powder of approximately 1 micron, supplied within the PU foam structure matrix framework at 40 - 70 microns across the depth of the foam.

[0225] Example 1.1 Preparation of atomized additives Very high density silver sulfate with d = 5 (40 - 70 microns, Alfa Aesar) was introduced into the inlet of an air injection milling device (Dietrich Engineering Consulting, Conika dry mill). The settings (injection and milling line gas pressure and silver sulfate feed rate) were adjusted to reduce the median particle size to 1 - 10 microns. Powder charges were obtained in several grades.

[0226] Samples of atomized silver sulfate were measured by a Malvern Mastersizer, for example, after ultrasonic treatment of the dispersion of the powder in methanol as follows. D50 ~ 3 microns, D50 ~ 6 microns, D50 ~ 14 microns.

[0227] Also, the atomized silver sulfate was evaluated for particle size distribution by the method disclosed herein, for example, as follows. Average 1.6 (0.4 - 5.3) microns, Average 1.9 microns (0.7 - 5 microns). Example 1.2 Preparation of powder charges

[0228] The powder charge was prepared from silver sulfate supplied from Example 1.1 or atomized, either alone or in combination with, for example, PEG3350 (bulking agent, 80 microns) and / or fumed silica (flow agent <1 micron) and / or charcoal (secondary additive) as shown in Table 1.

[0229]

Table 1

[0230] Example 2 Preparation of a PU (powder charge) - loaded PU foam composite An ALLEVYN polyurethane foam (2 mm thick) or a *double - layer laminate with superabsorbent fleece was provided to Fibroline SA together with the powder charge from Example 1, which was gravimetrically dosed.

[0231] Fibroline SA, in many samples, In Ex. 2.1 - 2.4, at different equivalent loading doses (TS) of 1.6 mg / cm 2 and (atomized) 0.8 mg / cm 2 , 1.1 mg / cm 2 , 1.4 mg / cm 2 the assembly of the antibacterial material was carried out as follows, using, for example, the proprietary technology described in US Patent No. 2016 / 0229890. The powder charge was dosed onto the release surface of the matrix or into the gravimetrically dosed matrix placed above or below the matrix, and an AC electrostatic field was applied to the matrix to cause the powder charge to penetrate into the cell network of the PU foam proximal to the loaded release surface.

[0232] Samples containing a flow agent and / or a bulking agent leave an acceptable amount (ideally none) on the dosing gravimetric and are accurately loaded onto the foam surface. Samples containing a flow agent are loaded more efficiently than samples without a flow agent.

[0233] ​The material was heated to soften the matrix and / or extender contained in the powder charge, thereby positioning the silver sulfate particles within the cell walls.

[0234] In the SEM images of the resulting material shown in FIGS. 3c, 3d, 3e, 3f, it can be seen that silver sulfate (bright spots) is loaded into the pores (dark gray relative to the gray cross-sectional structural matrix framework or gray cross-sectional cell surface). In FIG. 3c, the meandering of the pore network is illustrated. FIGS. 3d - 3h are SEM images of the material loaded with atomized silver sulfate. In FIGS. 3d, 3e, and 3f, it can be seen that the resulting asymmetric powder charge loading decreases the concentration of silver sulfate as the depth increases and translates to a depth of 1 mm within a 2 mm thick foam. In FIGS. 3g (secondary electrons (topography)) and 3h (backscattered electrons (bright zones = heavy elements, here silver)), both the softened extender and the positioned / incorporated silver sulfate can be seen.

[0235] Example 3 Preparation of Multilayer Coating Compositions The foams of Examples 2.1 - 2.4 were provided as Examples 2.1D - 2.4D corresponding to various commercially available deformations of the multilayer coating compositions illustrated in FIG. 5. ALLEVYN Gentle Border: 5b ALLEVYN Life: FIG. 5C ALLEVYN Gentle: 5b, no border ALLEVYN Life Non - Bordered: 5c, no border

[0236] Example 4 Silver Release Performance For the multilayer compositions CE1.1D, CE1.2D and Examples 2.1D - 2.4D, silver release was determined using the method described herein, i.e., the amount released into 50 mL of an aqueous medium as mg / cm of material per unit time. 2 Release was accumulated for the same medium sampled over 7 days, slowing the saturation of that particular fluid. The results are shown in FIG. 6.

[0237] All three types of multilayer compositions, P.O.M. (aqueous), P.O.M. (aqueous suspension), and composite (powder charge) loading, showed bolus release in the first 6 hours, then reached a steady state, and release continued for over 170 hours. The sample of Example 2D showed a larger bolus and higher sustained release at the lower equivalent loading dosage in Figure 6 as follows. Silver release from the coatings of Example 2.2D and Example 2.3D exceeded the silver release of CE1.2D at a lower loading (TS = total silver element). Silver release from the coating of Example 2.1D exceeded the silver release from CE2.1D at a lower loading (TS).

[0238] Example 5 Daily silver release performance Also, silver release was determined in the same manner as in Example 4, but daily, replenishing the release medium every day. The results shown in Figure 7 indicate that the silver release performance of the coating of Example 2.4D (loaded with micronized composite (powder charge)) exceeded that of CE1.2D (P.O.M. loading (aqueous suspension)) at equivalent loading (TS) up to 4 days, and was equivalent thereafter up to 7 days.

[0239] Examples 4 and 5 show an increased availability of additives in the asymmetric loading within the cell network loaded within the cell and, as further shown in Example 6, proximal to the release surface, close to the required location.

[0240] Also, Example 4 demonstrates excellent release achieved by the increased particle surface area from the micronized particles (Figure 6).

[0241] Example 6 Release surface For experimental purposes only, an asymmetric material was prepared in approximately 3 mg / cm 2 of highly micronized silver sulfate with a TS according to Example 2. The material was assembled into two coatings: Example 6.1D: Silver-rich side proximal to the wound contact layer (i.e., the loading and release surface) Example 6.2D: Silver-deficient surface (i.e., back surface) proximal to the wound contact layer

[0242] Using the method of Example 4, the silver release from the wound contact surfaces of both coatings was measured for 7 days, and the results are shown in Figure 8.

[0243] Coating 6.1D resulted in very high silver release. This demonstrates that, in contrast to prior art materials and methods with limited solubility, the release can be optionally adapted by increasing the loading in the materials and methods of this specification.

[0244] Coating 6.2D showed only slight release from the coating composition, with silver ions being retained within the coating, rendering the coating antibacterial, but with minimal impact on the release site, which is generally the wound bed. This demonstrates that the total silver water content strategically loaded at the wound contact surface in the asymmetric materials using the asymmetric methods of this specification is more readily available for release to the wound bed and can provide improved silver release, or can facilitate the provision of a reduced amount of silver salt within the material or coating.

[0245] Example 7 Sterilization The samples of Example 2 were coated with a silicone wound contact layer, cut into 2×2 cm squares, assembled using the layer according to Figure 5c of this specification, sealed at high temperature for lamination, and each of the three samples was sterilized by an ethylene oxide cycle to determine the ionic silver relative to the corresponding non-sterilized samples. The results shown in Figure 9 indicate that sterilization did not affect the ionic silver.

[0246] Example 8 Coating composition forms with different silver release performance Different multilayer compositions of Example 2D were compared for silver ion release using the method of Example 4. The results shown in Figure 10 demonstrate that bolus and sustained silver ion release are retained in different forms of multilayer compositions.

[0247] The samples were properly tested for Staphylococcus aureus and Pseudomonas aeruginosa.

[0248] Visualization of additive surface enrichment In some embodiments, after administering or loading the powder charge into the matrix described herein, the matrix may exhibit a non-uniform spatial distribution of the powder charge and / or the additive. In some embodiments, for example, as shown in FIG. 4, the maximum enrichment of the powder charge and / or the additive may be present on one or more foam surfaces (e.g., the site contact surface, the wound contact surface), and gradually decreases as the depth below the bulk foam surface increases.

[0249] Surface enrichment of loaded additives such as silver sulfate can be visualized two-dimensionally using backscattered scanning electron microscopy (b-SEM) of a planar cross-section through the depth of the foam, and three-dimensionally using high-resolution (the instrument used must be better than a spatial resolution of 35 microns) microfocus X-ray computed tomography (μ-XCT). The use of both visualization techniques can be beneficial because of the limitations in the spatial resolution of the microfocus X-ray computed tomography instrument. The matrix and the loaded additive can be visualized simultaneously by both SEM and μ-XCT.

[0250] In some embodiments, a two-dimensional visualization method such as microscopic Raman spectroscopy can be used to map the spatial distribution of the loaded additive across the surface of a planar cross-section of the foam. The polyurethane foam and silver sulfate can be mapped simultaneously by microscopic Raman spectroscopy.

[0251] In some embodiments, a two-dimensional visualization method such as micro X-ray fluorescence analyzer (μ-XRF) can be used to map the spatial distribution of silver and sulfur (the elemental components of silver sulfate) across the surface of a planar cross-section of the foam, although such elemental maps are overlaid on a macro optical image of the mapped area (the polyurethane foam cannot be mapped by μ-XRF).

[0252] Quantification of additive surface enrichment Quantification of the degree of additive enrichment can be achieved by image analysis based on gray-scale segmentation of b-SEM images (brightness of backscattered signals). By analyzing target regions located at different foam depths in the cross-sectional image, the 2D area coverage rate of silver sulfate can be obtained (in the b-SEM image, silver sulfate produces a brighter contrast than the polyurethane foam).

[0253] Quantification of the degree of silver sulfate enrichment can be achieved by image analysis based on gray-scale segmentation of μ-XCT images (X-ray opacity). By analyzing target volumes located at different foam depths in the three-dimensional image dataset, the 3D area occupancy of silver sulfate in the deeper volume of the target can be obtained (in the μ-XCT image, silver sulfate produces a higher X-ray opacity than the polyurethane foam).

[0254] Silver distribution in a PU foam having a composite material loaded with Example 9 (powder charge) For experimental purposes only, four other asymmetric materials were prepared by a method similar to Example 2 in the charging of silver sulfate. In these examples, the polyurethane (PU) foam layer was dry-impregnated with silver sulfate powder (about 1 - 2 mg / cm 2 ) as silver. During the impregnation process, a small amount of activated carbon and fumed silica can be added together with a powder binder (e.g., polyethylene glycol, PEG). Further, the silver may be ground to reduce its particle size or used as unground as supplied by the manufacturer.

[0255] Materials such as these samples can be impregnated through the cross-section of the PU foam sample to identify the presence of the binder and the effect of ground or unground silver for the following. · Depth of penetration of silver particles into the foam. · Whether there is segregation of particles during impregnation (PEG particles are larger than silver sulfate particles) that leads to differences in the distribution of silver sulfate across the depth of the foam (e.g., the surface concentration is higher in one case compared to the other).

[0256] The four foam samples were as follows: AD - A polyurethane foam with a thickness of 2 mm, 48 wt% silver sulfate, 48 wt% PEG100k, 3 wt% carbon, and 1 wt% silica. The silver dosage was in the range of 0.76 - 0.88 mg / cm 2 . AC - A polyurethane foam with a thickness of 2 mm, 48 wt% unground silver sulfate, 48 wt% PEG100k, 3 wt% carbon, and 1 wt% silica. The silver dosage was in the range of 0.67 - 0.88 mg / cm 2 . AE - A polyurethane foam with a thickness of 2 mm, 96 wt% dry - ground silver sulfate, 3 wt% carbon, and 1 wt% silica. The silver dosage was in the range of 2.31 - 2.59 mg / cm 2 . AB - A polyurethane foam with a thickness of 2 mm, 96 wt% unground silver sulfate, 3 wt% carbon, and 1 wt% silica. The silver dosage was in the range of 1.68 - 1.96 mg / cm 2 .

[0257] The particle size distribution of the dry - ground silver sulfate was approximately 2 microns < D10 < approximately 5 microns, approximately 5 microns < D50 < approximately 10 microns, and approximately 10 microns < D90 < approximately 18 microns. The particle size distribution of the unground silver sulfate was approximately 10 microns < D10 < approximately 25 microns, approximately 30 microns < D50 < approximately 60 microns, and approximately 50 microns < D90 < approximately 90 microns. In some embodiments, the ground silver sulfate may have particle sizes of 4 microns < D10 < 5 microns, 8 microns < D50 < 11 microns, and 16 microns < D90 < 19 microns, and the unground silver sulfate may have a particle size distribution of 10 microns < D10 < 15 microns, 20 microns < D50 < 40 microns, and 40 microns < D90 < 95 microns.

[0258] In the above samples, the PEG foam samples contain 2.5 - 3.5 times less silver sulfate than the non - PEG foam samples. The samples can be analyzed using SEM images, micro - CT images, or any other suitable technique.

[0259] Figure 4m shows an X-ray transmission image obtained from the above-described dried and impregnated silver sulfate foam sample, where the dark regions indicate silver sulfate. The sample foam sample of crushed silver sulfate had a more defined silver sulfate distribution, which corresponded to the nodes arranged in the checkerboard pattern observed on the supplied foam. In contrast, the uncrushed silver sulfate foam sample had a relatively more random silver sulfate distribution (see the planar transmission image shown in Figure 4m). There is some indication that the uncrushed sample AB has higher silver sulfate at the nodes, but this is not as clear as in the case of the crushed sample. The cross-sectional X-ray transmission image shows the silver sulfate that penetrated into the foam at different depths, as will be discussed below. Thus, in some embodiments, the powder charge may be loaded in a random distribution, and in other embodiments, the powder charge may be loaded to provide a pattern such as a checkerboard pattern.

[0260] Figure 4n illustrates SEM cross-sectional images of each of the asymmetric materials obtained by the method described herein, and Figure 4n illustrates microfocus X-ray computed tomography (μ-XCT) images of each of the asymmetric materials obtained by the method described herein. Cross-sectional images of the pulverized samples were obtained approximately through the center of the nodes. As shown in Figures 4n-4o, in some embodiments, silver sulfate may be impregnated in a plurality of pyramid shapes, the base of the pyramid is on the surface of the node, and the tip of the pyramid is further within the foam (e.g., 0.4 mm to 0.8 mm within the foam). In some embodiments, as shown in the sample of non-pulverized silver sulfate, silver sulfate may be distributed more randomly, in which case the bulk on the non-pulverized silver sulfate appears to be randomly dispersed within the foam at about 0.4 mm to about 0.8 mm. In some embodiments, silver sulfate is throughout the foam but may be dispersed at a much lower concentration than on the filled surface. In some embodiments, more than 50%, 70%, or 80% of the silver sulfate may be present within 0.8 mm from the surface of the foam. As shown in Figure 4o, the bulk of the silver sulfate in the non-PEG foam sample entered to a depth of about 0.8 mm of the foam, whereas, in contrast, the bulk in the PEG foam sample entered to a depth of about 0.4 mm of the foam. For all four foam samples, silver sulfate particles were observed throughout the foam but to a much lesser extent than on the surface of the impregnated foam. Thus, in some embodiments, the powder charge may be loaded with a bulk of particles (or any of the above percentages) provided within a specific distance of the surface of the matrix, e.g., within about 0.4 mm, or about 0.8 mm.

[0261] Negative pressure wound therapy (NPWT) Embodiments of the present disclosure will generally be understood to be applicable for use in a topical negative pressure (“TNP”) treatment system. Briefly, negative pressure wound therapy aids in closing and healing many forms of “difficult to heal” wounds by reducing tissue edema, promoting blood flow and granulation tissue formation, removing excessive exudate, and reducing the bacterial load (and thus the risk of infection). In addition, the treatment can reduce wound discomfort and lead to earlier healing. The TNP therapy system can also assist in the healing of surgically closed wounds by helping to remove fluid and stabilize tissue at the parallel positions of closure. Further beneficial uses of TNP treatment can be found in grafts and flaps where it is important to remove excessive fluid and the graft is required to be in proximity to the tissue to ensure tissue viability.

[0262] As used herein, a negative pressure or vacuum level, such as -X mmHg, represents a pressure level relative to normal ambient atmospheric pressure, which may correspond to 760 mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Thus, a negative pressure value of -X mmHg reflects an absolute pressure that is X mmHg lower than 760 mmHg, or, in other words, an absolute pressure of (760 - X) mmHg. Further, a negative pressure that is “lower” or “less” than X mmHg corresponds to a pressure closer to atmospheric pressure (e.g., -40 mmHg is lower than -60 mmHg). A negative pressure that is “higher” or “greater” than -X mmHg corresponds to a pressure further from atmospheric pressure (e.g., -80 mmHg is higher than -60 mmHg). In some embodiments, local ambient atmospheric pressure is used as a reference point, and such local atmospheric pressure may not necessarily be, for example, 760 mmHg.

[0263] For some embodiments of the present disclosure, the negative pressure range can be about -80 mmHg, or about -20 mmHg to -200 mmHg. It should be noted that these pressures are relative to normal ambient atmospheric pressure, which can be 760 mmHg. Therefore, -200 mmHg would be substantially about 560 mmHg. In some embodiments, the pressure range can be between about -40 mmHg and -150 mmHg. Alternatively, pressure ranges below -75 mmHg, below -80 mmHg, or above -80 mmHg can be used. Also, in other embodiments, pressure ranges below -75 mmHg can be used. As an alternative, a pressure range of approximately -100 mmHg or even above -150 mmHg can be supplied by the negative pressure device.

[0264] In some embodiments of the wound closure device described herein, an increase in wound contraction can lead to an increase in tissue expansion in the surrounding wound tissue. This effect may, in some cases, be enhanced by changing the force applied to the tissue in conjunction with an increase in the tensile force applied to the wound by an embodiment of the wound closure device, for example, by changing the negative pressure applied to the wound over time. In some embodiments, the negative pressure can be changed over time using, for example, a sine wave, a square wave, or in synchronization with one or more physiological indicators of the patient (e.g., heart rate). Examples of such applications, where further disclosure regarding the foregoing can be found, include U.S. Patent No. 8,235,955, entitled "Wound treatment apparatus and method," issued on August 7, 2012, and U.S. Patent No. 7,753,894, entitled "Wound cleansing apparatus with stress," issued on July 13, 2010. The disclosures of both patents are hereby incorporated by reference in their entirety.

[0265] Embodiments of the wound dressings, wound dressing components, wound treatment devices, and methods described herein may also be used in combination with, or in addition to, those described in "APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY", filed as International Application No. PCT / IB2013 / 001469 on May 22, 2013, and published as International Publication No. 2013 / 175306A2 on November 28, 2013, and "WOUND DRESSING", filed as International Application No. PCT / IB2013 / 002060 on July 31, 2013, and published as International Publication No. 2014 / 020440, the disclosures of which are hereby incorporated by reference in their entirety. Embodiments of the wound dressings, wound treatment devices, and methods described herein may also be used in combination with, or in addition to, those described in U.S. Patent No. 9,061,095, titled "WOUND DRESSING AND METHOD OF USE", issued on June 23, 2015, and U.S. Patent Publication No. 2016 / 0339158, titled "FLUIDIC CONNECTOR FOR NEGATIVE PRESSURE WOUND THERAPY", published on November 24, 2016, the disclosures of which are hereby incorporated by reference in their entirety, including further details regarding embodiments of the wound dressings, components and principles of the wound dressings, and materials used in the wound dressings.

[0266] In addition, some embodiments related to TNP wound treatment involving wound dressings in combination with pumps or associated electronics described herein may also be used in combination with, or in addition to, those described in "REDUCED PRESSURE APPARATUSES", published as International Publication No. 2016 / 174048 A1 on November 3, 2016, the entire disclosure of which is hereby incorporated by reference. In some of these embodiments, the pump or associated electronics may be incorporated into the wound dressing to provide a single article that is applied to the wound.

[0267] Multilayer wound dressing Any multilayer wound dressing may incorporate or include the loaded matrix as described above. Such wound dressings may incorporate a loaded matrix layer, composite, or laminate that includes the loaded matrix. For example, as previously described and illustrated in FIGS. 1-10, a loaded foam layer that includes a powder charge / additive loaded polyurethane (PU) material may be incorporated into the multilayer wound dressing. As previously described herein, a powder charge or additive loaded onto a polyurethane (PU) material may be configured to be activated, for example, by contact with a wet or aqueous medium to release chemical species (e.g., antibacterial species). Thus, the loaded matrix may be configured to release antibacterial species, for example, upon contact with a wet or aqueous medium, such as wound exudate. To facilitate the release and diffusion of antibacterial species into the wound, the loaded matrix may be placed proximal to the wound within the wound dressing.

[0268] In some embodiments, a method of treating a wound or site is provided. The method can include placing, across the wound, a multilayer wound dressing having a loaded matrix, such as a fibrous or foam layer, containing the powder charge / additive described herein, such that the wound dressing contacts the wound. Examples of such wound dressings have been described above and are further described below. The wound dressing can be adhered to healthy skin around the wound. The method can further include allowing wound exudate to reach and / or contact the loaded matrix layer. In some embodiments, a negative pressure may be applied to the wound dressing such that wound exudate is drawn into the wound dressing. In some embodiments, wound exudate can diffuse or be wicked into the wound dressing. In some embodiments, any wet or aqueous medium other than wound exudate can be provided to the wound dressing. Upon contact with the wet or aqueous medium, whether provided by wound exudate or not, the loaded matrix layer can release antibacterial species as described above. At least a portion of the released antibacterial species can be released into the wound, for example, by diffusion. In some embodiments, the antibacterial species can be silver ions. In some embodiments, the antibacterial species can be released into the wound for an extended period, for example, up to 1 day, 5 days, 7 days, or 10 days or more. In some embodiments, silver ions can be released at a maximum of 0.1 mg / cm 2 per day, up to 1.2 mg / cm 2 per day, 1.8 mg / cm 2 per day. Multilayer wound dressing for NPWT

[0269] FIG. 11 illustrates one embodiment of a negative pressure wound therapy system 700. The system includes a wound recess 710 covered by a wound dressing 720, which can be a dressing according to any of the examples described herein. The dressing 720 is positioned over or within the wound recess 710 and can further seal the wound recess so that a negative pressure can be maintained within the wound recess. For example, the film layer of the wound dressing 720 can provide a substantially fluid-impermeable seal covering the wound recess 710. In some embodiments, a wound filler such as a foam or gauze layer can be utilized to wrap the wound. The wound filler can include the loaded matrix described above. For example, in a conventional negative pressure wound therapy system that utilizes a foam or gauze, such as the Smith & Nephew negative pressure wound therapy system that utilizes a foam (RENASYS-F) or gauze (RENASYS-G), as described above, the foam or gauze can be replaced or supplemented with a loaded matrix layer, composite, or laminate. When complementing a foam or gauze layer or other wound packing material, the loaded matrix layer, composite, or laminate can be inserted separately into the wound or pre-attached to the wound packing material for insertion into the wound.

[0270] One or more luminal tubes or conduits 740 connect the wound dressing 720 to a negative pressure device 750 configured to supply a reduced pressure. The negative pressure device 750 includes a negative pressure source. The negative pressure device 750 can be a canisterless device (meaning that exudate is collected by the wound dressing and / or transferred through the tube 740 to be collected elsewhere). In some embodiments, the negative pressure device 750 can include or be configured to hold a canister. Further, in any of the embodiments disclosed herein, the negative pressure device 750 can be fully or partially embedded in the wound dressing 720, attached to the wound dressing 720, or held by the wound dressing 720.

[0271] The conduit 740 can be any suitable article configured to provide at least a substantially sealed fluid flow path or passageway between the negative pressure device 750 and the wound recess 710 so as to supply a reduced pressure to the wound recess. The conduit 740 can be formed from polyurethane, PVC, nylon, polyethylene, silicone, or any other suitable rigid or flexible material. In some embodiments, the wound dressing 720 can have a port configured to receive an end of the conduit 740. For example, the port can include a hole within the film layer. In some embodiments, the conduit 740, alternatively, can pass through and / or under the film layer of the wound dressing 720 to supply a reduced pressure to the wound recess 710 so as to maintain a desired level of reduced pressure within the wound recess. In some embodiments, at least a portion of the conduit 740 is integral with or attached to the wound dressing 720.

[0272] Figures 12A-12B illustrate an embodiment of a negative pressure wound therapy system 10 using a wound dressing 100 together with a fluid connector 110. Additional examples related to negative pressure wound therapy involving a wound dressing in combination with a pump described herein may be used in combination with or added to those described in U.S. Patent No. 9,061,095, which is hereby incorporated by reference in its entirety. In the figures, the fluid connector 110 may include an elongated conduit, and more preferably, a bridge 120 having a proximal end 130 and a distal end 140, and an applicator 180 at the distal end 140 of the bridge 120. The system 10 may include a negative pressure source, such as a pump or a negative pressure unit 150 capable of supplying negative pressure. The pump may include a canister or other container for storing wound exudate and other fluids that can be removed from the wound. The canister or container may also be provided separately from the pump. In some embodiments, as illustrated in Figures 12A-12B, the pump 150 may be a pump without a canister, such as a PICO (trademark) pump sold by Smith & Nephew. The pump 150 may be connected to the bridge 120 via a tube 190, or the pump 150 may be directly connected to the bridge 120. In use, the dressing 100 is placed over a suitably prepared wound, which may in some cases be filled with a wound packing material such as the foam or gauze described above. The applicator 180 of the fluid connector 110 has a sealing surface that is placed over a gap in the dressing 100 and sealed to the uppermost surface of the dressing 100. Prior to, during, or after connection of the fluid connector 110 to the dressing 100, the pump 150 is connected to a coupling 160 via a tube 190 or directly to the bridge 120. The pump is then activated, thereby supplying negative pressure to the wound. Application of the negative pressure may be performed until a desired level of wound healing is achieved.

[0273] As shown in FIG. 12C, the fluid connector 110 preferably includes an enlarged distal end or head 140 that is in fluid communication with the dressing 100, as described in further detail below. In one embodiment, the enlarged distal end has a rounded or circular shape. The head 140 is shown in the figure as being located near the end of the dressing 100, but it can be disposed at any location on the dressing. For example, some embodiments can be provided at a central or off-center location that is not at or near the end or corner of the dressing 100. In some embodiments, the dressing 10 may comprise two or more fluid connectors 110, each including one or more heads 140 in fluid communication therewith. In a preferred embodiment, the head 140 can be 30 mm along its widest edge. The head 140 at least partially forms an applicator 180 that is configured to be sealed against the uppermost surface of the wound dressing described above.

[0274] FIG. 12D shows a cross-section of a wound dressing 100 similar to the wound dressing 10 shown in FIG. 12B together with the fluid connector 110, which is described in International Patent Publication WO2013 / 175306A2 and is incorporated by reference in its entirety. Alternatively, the wound dressing 100, which can be any of the wound dressing embodiments disclosed herein or any combination of any number of features of the wound dressing embodiments disclosed herein, can be placed over the wound site to be treated. The dressing 100 can be installed to form a cavity sealed over the wound site. In a preferred embodiment, the dressing 100 includes a backing layer 220 attached to the top layer or cover layer, or any wound contact layer 222, both of which are described in more detail below. These two layers 220, 222 are preferably joined or sealed together to define an internal space or chamber. This internal space or chamber may include additional structures adapted to distribute or transmit negative pressure and store wound exudate and other fluids removed from the wound, and other functions that will be described in more detail below. Examples of such structures described below include a permeable layer 226 and an absorbent layer 221.

[0275] As used herein, the upper layer, top layer or upper layer refers to the layer that is farthest from the skin or the surface of the wound while the covering material is in use and located over the wound. Thus, the bottom layer, lower layer, bottom layer or lower layer refers to the layer that is closest to the skin or the surface of the wound while the covering material is in use and located over the wound.

[0276] As shown in FIG. 12D, the wound contact layer 222 may be a polyurethane layer, a polyethylene layer, or another flexible layer that is perforated, for example, via a hot pin process, a laser ablation process, or an ultrasonic process, or in some other way to allow liquids and gases to permeate. The wound contact layer 222 has a bottom surface 224 and a top surface 223. The perforations 225 preferably include through holes in the wound contact layer 222, thereby allowing fluid to flow through the layer 222. The wound contact layer 222 helps prevent tissue ingrowth into other materials of the wound dressing. The perforations are preferably small enough to meet this requirement while allowing fluid to flow through them. For example, perforations formed as slits or holes having dimensions in the range of 0.025 mm to 1.2 mm are considered small enough to help prevent tissue from growing internally into the wound dressing while allowing wound exudate to flow into the dressing. In some configurations, the wound contact layer 222 may help maintain the integrity of the entire dressing 100 while creating an airtight state around the absorbent pad to maintain negative pressure on the wound.

[0277] Some embodiments of the wound contact layer 222 may also serve as a carrier for any upper and lower adhesive layers (not shown). For example, a lower pressure sensitive adhesive may be provided on the lower surface 224 of the wound dressing 100, while an upper pressure sensitive adhesive layer may be provided on the upper surface 223 of the wound contact layer. A pressure sensitive adhesive, which may be a silicone, hot melt, hydrophilic colloid or acrylic-based adhesive, or other such adhesive, may be formed on both surfaces of the wound contact layer, or optionally on a selected one of the surfaces, or may not be formed on either surface of the wound contact layer. Utilizing a lower pressure sensitive adhesive layer may help to adhere the wound dressing 100 to the skin around the wound site. In some embodiments, the wound contact layer may comprise a perforated polyurethane film. The lower surface of the film may be provided with a silicone pressure sensitive adhesive and the upper surface may be provided with an acrylic pressure sensitive adhesive, thereby helping to maintain the integrity of the dressing. In some embodiments, adhesive layers may be provided on both the upper and lower surfaces of the polyurethane film layer, and all three layers may be perforated together.

[0278] The permeable layer 226 can be placed above the wound contact layer 222. In some embodiments, the permeable layer can be a porous material. As used herein, the permeable layer can be referred to as a spacer layer, and the terms can be used interchangeably to mean the same components described herein. This permeable layer 226 enables fluids, including liquids and gases, to permeate away from the wound site and into the upper layer of the wound dressing. In particular, it is preferred that the permeable layer 226 ensures that the outside air channel is maintained such that, even if the absorption layer absorbs a significant amount of exudate, a negative pressure is transmitted over the wound area. Layer 226 should preferably remain open under the normal pressure that will be applied during negative pressure wound therapy, as described above, so that the entire wound site receives an equal negative pressure. Layer 226 can be formed from a material having a three-dimensional structure. For example, a knitted or woven spacer fabric (e.g., a warp-knitted polyester such as Baltex 7970), or a non-woven fabric can be used. The three-dimensional material can include 3D spacer fabric materials similar to those described in International Patent Publication No. WO2013 / 175306A2 and International Patent Publication No. WO2014 / 020440, the disclosures of which are hereby incorporated by reference in their entirety.

[0279] The wound dressing 100 may incorporate or include a loaded matrix as described herein. For example, as described above herein and as illustrated in FIGS. 1-10, a powder charge / additive loaded polyurethane (PU) material or a fibrous material may be incorporated into the wound dressing 100. In some embodiments, the loaded matrix layer may be provided under the permeable layer 226. In some embodiments, the loaded matrix layer may be provided over the wound contact layer 222. In some embodiments, the loaded matrix layer may be replaced with the permeable layer 226 such that the loaded matrix layer is provided between the absorbent layer 221 (further described below) and the wound contact layer 222. In some embodiments, the loaded matrix layer may complement or replace the absorbent layer 221, or the absorbent layer 221 may be loaded with the powder charge described above. In some embodiments, the wound dressing 100 may not have a wound contact layer 222, and the loaded matrix layer may be the lowermost layer of the wound dressing 100. The loaded matrix may have the same or substantially similar size and shape as the permeable layer 226 and / or the absorbent layer 221.

[0280] The loaded matrix layer may be configured to be flexible yet firm enough to withstand negative pressure such that the loaded matrix does not disintegrate excessively and thereby sufficiently transmits negative pressure to the wound when negative pressure is applied to the wound dressing 100. The loaded matrix layer may be configured to include pores in a sufficient number or size to enable delivery of negative pressure therethrough. Further, the loaded matrix layer may have a thickness suitable for delivering sufficient negative pressure to the wound. For example, the loaded matrix layer may have a thickness of 1 mm to 5 mm, 1.5 mm to 4 mm, or 2 mm to 3 mm. In some embodiments, the loaded foam matrix may have a thickness of approximately 2 mm.

[0281] In some embodiments, a layer 221 of absorbent material is provided above the permeable layer 226. The absorbent material may include a foam or non-woven natural or synthetic material and may optionally include a superabsorbent material, and forms a reservoir for fluids, specifically liquids removed from the wound site. In some embodiments, layer 221 may also help draw fluid toward backing layer 220.

[0282] The material of absorbent layer 221 may also prevent liquid collected within wound dressing 100 from freely flowing within the dressing and preferably acts to contain any liquid collected within the dressing. Absorbent layer 221 also helps distribute fluid across the absorbent layer by a wicking action to draw fluid from the wound site and store it within the absorbent layer. This helps prevent pooling in the area of the absorbent layer. The capacity of the absorbent must be sufficient to manage the rate at which wound exudate flows when negative pressure is applied. During use, the absorbent layer experiences negative pressure, and thus the material of the absorbent layer is selected to absorb liquid under such circumstances. For example, there are several materials, such as superabsorbent materials, that can absorb liquid when under negative pressure. Absorbent layer 221 may typically be made from Freudenberg 114-224-4 of ALLEVYN™ foam or Chem-Posite™ 11C-450. In some embodiments, absorbent layer 221 may include a composite material including superabsorbent powder, fibrous materials such as cellulose, and binder fibers. In a preferred embodiment, the composite material is an airlaid, thermally bonded composite material.

[0283] In some embodiments, the absorbent layer 221 is a layer of non-woven cellulose fibers having a superabsorbent material in the form of dry particles dispersed throughout the layer. The use of cellulose fibers introduces a high-speed wicking element that helps to quickly and evenly distribute the liquid absorbed by the coating material. Aligning a number of twisted-like fibers leads to a strong capillary action of the fiber pad that helps to distribute the liquid. In this way, the liquid is efficiently supplied to the superabsorbent material. Also, the wicking action helps to bring the liquid into contact with the upper cover layer so as to help increase the evaporation rate of the coating material.

[0284] A gap, hole or orifice 227 is preferably provided in the backing layer 220 so as to enable the application of a negative pressure to the dressing 100. The fluid connector 110 is preferably attached or sealed on top of the backing layer 220 over the orifice 227 made in the dressing 100 to convey the negative pressure through the orifice 227. A long tube can be connected to the fluid connector 110 at the first end and to a pump unit (not shown) at the second end so as to enable the pumping of fluid from the dressing. When the fluid connector adheres to the top layer of the wound dressing, the long tube can be connected at the first end of the fluid connector such that the tube or conduit extends away from the fluid connector parallel to, or substantially to, the top surface of the dressing. The fluid connector 110 can be adhered and sealed to the backing layer 220 using an adhesive such as acrylic, cyanoacrylate, epoxy, UV curable or hot melt adhesive. The fluid connector 110 can be formed from a soft polymer such as polyethylene, polyvinyl chloride, silicone or polyurethane having a hardness on the Shore A scale of 30 to 90. In some embodiments, the fluid connector 110 may be made from a soft or conformable material.

[0285] Optionally, the absorbent layer 221 includes at least one through-hole 228 disposed such that it is beneath the fluid connector 110. The through-hole 228 may, in some embodiments, be the same size as the aperture 227 of the backing layer, or may be larger or smaller. As illustrated in FIG. 12D, a single through-hole may be used to provide an opening beneath the fluid connector 110. It will be understood that multiple openings may alternatively be utilized. Additionally, if two or more ports are to be utilized according to a particular embodiment of the present disclosure, one or more openings may be made in the absorbent layer in alignment with each fluid connector. Although not essential to a particular embodiment of the present disclosure, the use of through-holes in the superabsorbent layer can provide an unobstructed fluid flow path, particularly when the absorbent layer is near saturation.

[0286] The gap or through-hole 228 is preferably provided in the absorbent layer 221 below the orifice 227 such that the orifice communicates directly with the permeable layer 226, as shown in FIG. 12D. This allows the negative pressure applied to the fluid connector 110 to be transmitted to the permeable layer 226 without passing through the absorbent layer 221. This ensures that when the absorbent layer absorbs wound exudate, the negative pressure applied to the wound site is not inhibited by the absorbent layer. In other embodiments, the gap may not be provided in the absorbent layer 221, or alternatively, multiple gaps may be provided below the orifice 227. In further alternative embodiments, an additional layer such as another permeable layer, or an obscuring layer as described in and incorporated by reference in its entirety by International Patent Publication No. WO2014 / 020440, as illustrated in FIGS. 16A - 16B, may be provided above the absorbent layer 221 and below the backing layer 220.

[0287] The backing layer 220 preferably does not allow gas to pass through but allows water vapor to pass through, and can extend across the width of the wound dressing 100. For example, the backing layer 220 can be a polyurethane film (e.g., Elastollan SP9109) having a pressure-sensitive adhesive on one side. The backing layer 220 is impermeable to gas, and thus this layer operates to cover the wound and seal the wound cavity on which the wound dressing is placed. In this way, an effective chamber is created between the backing layer 220 and the wound site where negative pressure can be established. The backing layer 220 is sealed to the wound contact layer 222 within the boundary region around the dressing, and it is preferable to prevent air from being sucked into the boundary region, for example, via an adhesion technique or a welding technique. The backing layer 220 protects the wound from external bacterial contamination (bacterial barrier), allows liquid to move from the wound exudate through the layer, and evaporate from the outer surface of the film. The backing layer 220 preferably includes two layers, namely a polyurethane film and an adhesive pattern spread on this film. The polyurethane film is preferably moisture-permeable and can be manufactured from a material with a high water permeation rate when wet. In some embodiments, the moisture permeability of the backing layer increases when the backing layer is wet. The moisture permeability of the wet backing layer can be up to about 10 times that of the dry backing layer.

[0288] The absorption layer 221 may cover a larger area than the permeation layer 226 so as to overlap the edge of the permeation layer 226, thereby ensuring that the permeation layer does not contact the backing layer 220. This provides an outer channel of the absorption layer 221 that is in direct contact with the wound contact layer 222, which helps to more rapidly absorb exudate into the absorption layer. Further, this outer channel ensures that liquid cannot accumulate on the outer periphery of the wound cavity, which otherwise might seep out from the seal around the dressing and lead to leakage. As shown in FIGS. 12C - 12D, the absorption layer 221 may define a perimeter smaller than that around the backing layer 220 such that a boundary line or boundary region is defined between the end of the absorption layer 221 and the end of the backing layer 220.

[0289] As shown in FIG. 12D, one embodiment of the wound dressing 100 includes a gap 228 in the absorbent layer 221 disposed below the fluid connector 110. In use, for example, when negative pressure is applied to the dressing 100, the portion of the fluid connector facing the wound may contact the permeable layer 226 and thus may help transmit negative pressure to the wound site even when the absorbent layer 221 is filled with wound fluid. In some embodiments, the backing layer 220 may be at least partially adhered to the permeable layer 226. In some embodiments, the gap 228 is at least 1-2 mm larger than the diameter of the portion of the fluid connector 11 facing the wound or the orifice 227.

[0290] In particular, in embodiments with a single fluid connector 110 and a through-hole, as shown in FIG. 12C, the fluid connector 110 and the through-hole may preferably be located at an off-center position. In such a location, it may be possible to position the dressing 100 on the patient such that the fluid connector 110 is lifted relative to the remainder of the dressing 100. When arranged in this way, the fluid connector 110 and the filter 214 may be less likely to come into contact with wound fluid that could prematurely occlude the filter 214 to reduce the transmission of negative pressure to the wound site.

[0291] Similar to the embodiments of the wound dressing described above, some wound dressings include a perforated wound contact layer with a silicone adhesive on the skin contact surface and an acrylic adhesive on the back surface. In some embodiments, the wound contact layer can be composed of polyurethane, polyethylene, or polyester. Above this bordered layer is a permeable layer. Above the permeable layer is an absorbent layer. The absorbent layer can include a superabsorbent non-woven (NW) pad. The absorbent layer can contact the permeable layer for approximately 5 mm beyond the perimeter. The absorbent layer can have a gap or through-hole towards one end. The gap can be approximately 10 mm in diameter. Above the permeable layer and the absorbent layer is a backing layer. The backing layer can be a high moisture vapor transmission rate (MVTR) film that is a pattern coated with an acrylic adhesive. The high MVTR film and the wound contact layer enclose the permeable layer and the absorbent layer to create a perimeter boundary of approximately 20 mm. The backing layer can have a 10 mm gap that overlaps the gap in the absorbent layer. Above the hole, a fluid connector can be coupled that includes a liquid-impermeable, gas-permeable semi-permeable membrane (SPM) or filter that overlaps the aperture described above.

[0292] Multilayer dressing for use without negative pressure Figures 13A - 13D show various embodiments of a wound dressing 500 that can be used to heal a wound without negative pressure. Figure 13E shows a cross-sectional view of the wound dressings of Figures 13A - 13D, which is similar to the structure of Figure 5c. As shown in the dressings of Figures 13A - 13E, the wound dressing can have multiple layers similar to the dressings described with reference to Figures 12A - 12D, except that the dressings of Figures 13A - 13E do not include a port or a fluid connector. The wound dressings of Figures 13A - 13E can include a cover layer 501 and an optional wound contact layer 505 as described herein. In some embodiments, the cover layer 501 can be permeable to moisture and / or air. The wound dressing can include various layers located between the wound contact layer 505 and the cover layer 501. For example, the dressing can include one or more absorbent layers or one or more permeable layers as described herein with reference to Figures 12A - 12D.

[0293] As shown in FIGS. 13A - 13E, the dressing 500 includes a wound contact layer 505 and an upper film layer 501. Further components of the wound dressing 500 include a foam layer 504, such as a layer of polyurethane hydrocellular foam of a suitable size that covers the recommended wound dimensions corresponding to a selected specific dressing size. To enable odor control, an optional layer of any activated carbon cloth (not shown) of a size similar to or slightly smaller than that of layer 504 may be provided. An absorbent layer 502, such as a layer of superabsorbent airlaid material that includes cellulose fibers and superabsorbent polyacrylate particles, which is of a size slightly larger than that of layer 504 to allow for overlap of the superabsorbent material and functions as a leak prevention, is provided over layer 504. A masking or shielding layer 503, such as a layer of three - dimensional knitted spacer fibers, is provided over layer 502, enabling partial masking of the uppermost surface of the superabsorbent while providing protection from pressure. In this embodiment, this is of a size smaller (in plan view) than layer 502, allowing visibility of the edge of the absorbent layer and can be used to evaluate whether a clinician needs to replace the dressing.

[0294] The wound dressing 500 may incorporate or include a loaded matrix as described above. For example, as previously described herein and as illustrated in FIGS. 1 - 10, a loaded foam or fiber layer containing a powder charge / additive may be incorporated within the wound dressing 500. In some embodiments, the loaded matrix layer may be provided under the cover layer 501. In some embodiments, the loaded matrix layer may be provided over the wound contact layer 505. In another embodiment, the dressing 500 may not include the wound contact layer 505 such that the loaded matrix layer is the bottom - most layer and is configured to contact the wound surface. In some embodiments, the loaded matrix layer may be provided under the foam layer 504. In some embodiments, the loaded matrix layer may be replaced by the foam layer 504.

[0295] As described above, the loaded matrix, and the loaded foam including, for example, an antibacterial powder charge / additive loaded urethane (PU) material can be incorporated into commercially available dressings such as ALLEVYN™ foam, ALLEVYN™ Life, ALLEVYN™ Adhesive, ALLEVYN™ Gentle Border, ALLEVYN™ Gentle, ALLEVYN™ Ag Gentle Border, ALLEVYN™ Ag Gentle. In some embodiments, the wound dressing 500 can include a cover layer 501 and a loaded foam layer disposed under the cover layer 501 and configured to be disposed over a wound similar to the wound dressing configurations described above in connection with FIG. 5a. The loaded foam can include an adhesive such that the foam layer can be adhered to healthy skin around the wound. In some embodiments, the wound dressing 500 can include a cover layer 501, a wound contact layer 505, and a loaded foam layer sandwiched therebetween, similar to the wound dressing configurations described above in connection with FIG. 5b. In some embodiments, the wound dressing 500 can include a cover layer 501, an absorption layer 502, a loaded foam layer below the absorption layer 502, and a wound contact layer 505, similar to the wound dressing configurations described above in connection with FIG. 5c.

[0296] Further details regarding wound dressings that can be used in combination with or in addition to the embodiments described herein can be found in U.S. Patent No. 9,877,872, issued January 30, 2018, entitled "WOUND DRESSING AND METHOD OF TREATMENT", which disclosure is hereby incorporated by reference in its entirety herein, including further details regarding wound dressing embodiments, wound dressing components and principles, and materials used in wound dressings.

[0297] Multi-layer wound dressing with integrated negative pressure source In some embodiments, some or all of the other components of the TNP system, such as a negative pressure source (e.g., a pump), and a power source, sensors, connectors, user interface components (buttons, switches, speakers, screens, etc.), can be integrated with the wound dressing. Further, some embodiments related to wound treatment including the wound dressings described herein may be used in combination with or in addition to those described in International Application No. WO2016 / 174048 and International Patent Application No. PCT / EP2017 / 055225, entitled "WOUND TREATMENT APPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCE INTEGRATED INTO THE WOUND DRESSING", filed on Mar. 6, 2017, the disclosure of which is hereby incorporated by reference in its entirety and includes details regarding embodiments of the wound dressing, wound dressing components and principles, as well as materials used in the wound dressing and further details regarding the wound dressing components.

[0298] In some embodiments, a pump and / or other electronic components are still part of a single device that will be applied to a patient with the pump and / or other electronics located remotely from the wound site, but the pump and / or other electronic components can be configured to be adjacent to and / or next to the absorber and / or permeable layer of the wound dressing. FIGS. 14A - 14B show a wound dressing incorporating a negative pressure source and / or other electronic components within the wound dressing. FIGS. 14A - 14B illustrate a wound dressing 1200 with the pump and / or other electronics positioned remotely from the wound site. The wound dressing can comprise an electronics area 1261 and an absorption area 1260. The dressing can include a wound contact layer (not shown) and a moisture permeable film, i.e., a cover layer 1213, positioned over the contact layer and other layers of the dressing. The wound dressing layers and the components of the electronics area and absorption area can be covered by a single continuous cover layer 1213 as shown in FIGS. 14A - 14B.

[0299] The electronic device area 1261 may include a negative pressure source (such as a pump) and some or all of the other components of the TNP system that can be integrated with the wound dressing, such as a power supply, a sensor, a connector, user interface components (buttons, switches, speakers, screens, etc.). For example, as shown in FIGS. 14A - 14B, the electronic device area 1261 may include a button or switch 1211. The button or switch 1211 can be used to operate the pump (e.g., turn the pump on / off).

[0300] The absorption area 1260 may include an absorbent material 1212 and can be placed over the wound site. The electronic device area 1261 can be placed away from the wound site, such as by being laterally offset from the absorption area 1260. As shown in FIGS. 14A - 14B, the electronic device area 1261 can be adjacent to the absorption area 1260 or placed next to it in fluid communication with the absorption area 1260. In some embodiments, the electronic device area 1261 and the absorption area 1260 may each be rectangular and can be placed adjacent to each other.

[0301] In some embodiments, an additional layer of the dressing material can be provided within the electronic device area 1261, the absorption area 1260, or both. In some embodiments, the dressing may include one or more spacer or permeable layers and / or one or more absorption layers disposed above the contact layer and below the wound cover layer 1213 of the dressing.

[0302] The covering material may include a wound contact layer (not shown), a permeation layer (not shown), an absorption layer 1212 above the permeation layer, and a moisture-permeable film or cover layer 1213 positioned above the wound contact layer, the permeation layer, the absorption layer, or other layers of the covering material. The wound contact layer may be configured to contact the wound. The wound contact layer may be provided on the side facing the patient to fix the covering material to the surrounding skin with an adhesive, or may be provided on the upper side to fix the wound contact layer to the cover layer or other layers of the covering material. During operation, the wound contact layer may be configured to provide a unidirectional flow to facilitate removal of exudate from the wound while preventing or substantially preventing the exudate from returning to the wound. One or more permeation layers assist in distributing negative pressure over the wound site and facilitating transport of wound exudate and fluid into the wound dressing. In some embodiments, the permeation layer may be at least partially formed from three-dimensional (3D) fibers. Additionally, an absorption layer (such as layer 1212) may be utilized to absorb and retain exudate suctioned from the wound. In some embodiments, a superabsorbent material may be used for the absorption layer 1212. In some embodiments, the absorbent body comprises a shaped superabsorbent layer form. The wound dressing layer and the absorption layer in the electronic device area may be covered by a single continuous cover layer 1213. In some embodiments, the cover layer may comprise a moisture-permeable material that allows passage of gas while preventing passage of exudate of liquid removed from the wound and other liquids.

[0303] FIG. 14C illustrates an embodiment of a layer of a wound dressing in which the pump and electronic components are offset from the absorption area of the dressing. As shown in FIG. 14C, the dressing may comprise a wound contact layer 1310 for placement in contact with the wound. Lower spacer layer or permeable layers 1311 and 1311' are provided above the wound contact layer 1310. In some embodiments, as shown in FIG. 14C, the permeable layer 1311 may be a separate layer from the spacer layer 1311'. The lower permeable layer 1311 and / or 1311' may assist in evenly distributing pressure over the wound surface and / or allowing fluid to escape from the wound. The absorption layer 1322 may be positioned above the lower permeable layer 1311. The dressing layer 1351 may comprise a notch or recess 1328 for embedding the electronic component 1350 within the layer 1351. In some embodiments, the notch or recess 1328 may be sized or shaped to receive the pump 1327, power source 1326, and / or other electronic components. In some embodiments, the layer 1351 may comprise a plurality of spacer layers or permeable layers stacked together. In some embodiments, the layer 1351 may comprise a plurality of spacer layers or permeable layers joined together to surround the electronic component 1350. The upper permeable layer 1317 may be provided above the absorption layer 1322, layer 1351, and / or electronic component 1350.

[0304] The wound dressings 1200, 1300 may incorporate or include the loaded matrix as described above. For example, as previously described herein and illustrated in FIGS. 1-10, a loaded foam or fiber layer containing a powder charge / additive may be incorporated into the wound dressing. In some embodiments, the loaded matrix layer may be provided under the permeable layer 1311. In some embodiments, the loaded matrix layer may be provided under the wound contact layer 1310. In some embodiments, the loaded matrix layer may replace the permeable layers 1311, 1311' such that the loaded matrix layer is provided between the absorbent layer 1322 and the wound contact layer 1310. In some embodiments, the loaded matrix layer may complement or replace the absorbent layers 1212, 1322, or alternatively, the absorbent layers 1212, 1322 may be loaded with a powder charge as described above. In some embodiments, the loaded matrix layer may be the bottommost layer of the wound dressing. The loaded matrix layer may have the same or substantially similar size and shape as the permeable layer and / or absorbent layer described above.

[0305] The loaded matrix layer may be configured to be flexible but stiff enough to withstand negative pressure so that when the loaded foam collapses excessively, thereby applying a negative pressure to the wound dressing 1200, a negative pressure source is sufficiently delivered to the wound. The loaded matrix layer may be configured to include pores in a sufficient number or size to enable the delivery of negative pressure therethrough. Further, the loaded matrix layer may have a thickness suitable for delivering a sufficient negative pressure to the wound. For example, the loaded matrix layer may have a thickness of 1 mm to 5 mm, 1.5 mm to 4 mm, or 2 mm to 3 mm. In some embodiments, the loaded matrix layer may have a thickness of approximately 2 mm.

[0306] The cover layer or backing layer 1313 can be disposed on top of the upper transmission layer 1317. The backing layer 1313 can form a seal with the wound contact layer 1310 in the peripheral region surrounding the transmission layers 1311, 1311', and 1317, the absorption layer 1322, the layer 1351, and the electronic component 1350. In some embodiments, the backing layer 1313 can be a sheet of a flexible material that forms and molds around the dressing component when the dressing component is applied to the wound. In other embodiments, the backing layer 1313 can be a material that is pre-formed or pre-molded to fit around the dressing component, as shown in FIG. 14C.

[0307] Multilayer wound dressing for NPWT wrapped around a transmission layer FIG. 15A illustrates an embodiment of a TNP wound treatment device including a wound dressing. As described above, the wound dressing 400 can be any wound dressing embodiment disclosed herein, or can have any combination of features of any number of wound dressing embodiments disclosed herein. For example, the wound dressing 400 can be similar to the PICO single unit dressing available from Smith & Nephew as described above. The wound dressing 400 and associated systems can also be similar to the systems described above with reference to FIGS. 12A-12D. Embodiments of the wound dressings, wound dressing components, wound treatment devices, and methods described herein with reference to FIGS. 15A-15C can be used in combination with or in addition to International Patent Publication No. WO2017 / 114745A1, entitled "NEGATIVE PRESSURE WOUND THERAPY APPARATUS", published on Jul. 6, 2017, the entire disclosure of which is incorporated herein by reference.

[0308] The dressing 400 may be placed over the wound, and the port 460 may be used to provide negative pressure from a vacuum source to the wound (as described in connection with FIGS. 12A-12D, a fluid connector may be formed with the conduit 401). In the embodiment shown in FIG. 12A, the dressing 400 may comprise at least a portion of the conduit 401 pre-attached to the port 460. For example, the port / conduit combination may be a flexible suction adapter as described herein with reference to FIGS. 12A-12D. In some embodiments, the pre-attached conduit 401 may be connectable to a tube extension, e.g., a tube (not shown). It is preferred that the dressing 400 be provided as a single article with all wound dressing elements (including the port 460 and conduit 401) pre-attached and integrated into a single unit. The wound dressing 400 may then be connected via the conduit 401 and / or a conduit extension to a negative pressure source such as a pump as described with reference to FIGS. 12A-12D.

[0309] The cover layers 430, 320, clearly visible in FIGS. 15B - 15C, may be formed of a substantially fluid - impermeable material such as a film. The cover layers 430, 320 may be similar to the cover layer or backing layer described above with respect to FIGS. 12A - 12D. The film may be transparent so that other layers under the cover layer are also visible from the top view of FIG. 15A. The cover layer may comprise an adhesive for fixing the dressing to the surrounding skin or wound contact layer. The dressing may utilize the wound contact layers 440, 322 and the absorbent layers 450, 321 within the dressing. The wound contact layer and the absorbent layer may be similar to the wound contact layer and the absorbent layer described above with respect to FIGS. 12A - 12D. The wound contact layer may be configured to contact the wound. The wound contact layer may comprise an adhesive on the side facing the patient to fix the dressing to the surrounding skin or on the upper side to fix the wound contact layers 440, 322 to the cover layers 430, 320 or other layers of the dressing. In operation, in some embodiments, the wound contact layer may be configured to provide a one - way flow to facilitate removal of exudate from the wound while preventing or substantially preventing the exudate from returning to the wound. Further, an absorbent layer (such as layers 450, 321, etc.) for absorbing and holding the exudate aspirated from the wound may be utilized. In some embodiments, the absorbent layer can include an absorbent material, such as a superabsorbent material, or other absorbent materials known in the art. In some embodiments, the absorbent body may comprise a shaped superabsorbent layer form having recesses or compartments for a pump, electronics, and associated components. In some embodiments, the wound dressing may include a plurality of absorbent layers.

[0310] The absorbent material 450 shown in FIG. 15A may be a foam or non-woven natural or synthetic material, optionally including or being a superabsorbent material, and forms a reservoir for fluids removed from the wound site, specifically liquids, and draws those fluids towards the cover layer 430. The material of the absorbent layer may be similar to the absorbent materials described with reference to FIGS. 12A-12D. The material of the absorbent layer also prevents the liquid collected in the wound dressing from flowing in a sloshing manner. The absorbent layer 450 also helps distribute the fluid throughout the layer by a sucking action so as to draw the fluid from the wound site and store it across the absorbent layer, thereby assisting in preventing agglomeration in the area of the absorbent layer.

[0311] In some embodiments, the absorbent layer 450 is a layer of non-woven cellulose fibers having a superabsorbent material in the form of dry particles dispersed across the layer. The use of cellulose fibers introduces a high-speed sucking element that helps quickly and evenly distribute the liquid absorbed by the dressing. Aligning a number of twisted-like fibers leads to a strong capillary action of the fiber pad that helps distribute the liquid, thus efficiently supplying the liquid to the superabsorbent material and providing the liquid to all areas of the absorbent layer.

[0312] Also, the sucking action helps to bring the liquid into contact with the upper cover layer so as to help increase the transpiration rate of the dressing.

[0313] The sucking action also helps deliver the liquid downward towards the wound bed when exudation slows or stops. This delivery process helps maintain a permeable layer or lower spacer layer and the lower wound bed area, which prevents crust formation in the dressing (which can lead to occlusion) and helps maintain an environment optimized for wound healing.

[0314] In some embodiments, the absorbent layer 450 may be an airlaid material. Thermoplastic fibers may optionally be used to help hold the structure of the pad together. Of course, according to certain embodiments of the present invention, superabsorbent fibers can be utilized rather than, or in addition to, the use of superabsorbent particles. An example of a suitable material is Product Chem-Posite™ 11C available from Emerging Technologies Inc (ETi) in the United States.

[0315] Optionally, according to certain embodiments of the present invention, the absorbent layer 450 may include synthetic staple fibers and / or bicomponent staple fibers and / or natural staple fibers and / or superabsorbent fibers. The fibers within the absorbent layer may be secured together by latex bonding or thermal bonding or hydrogen bonding or any combination of bonding techniques or other fixing mechanisms. In some embodiments, the absorbent layer is formed by fibers that act to lock superabsorbent particles within the absorbent layer. This helps ensure that the superabsorbent particles do not migrate towards the wound bed outside and beneath the absorbent layer. When negative pressure is applied, the absorbent pad tends to collapse downward, and this action is particularly useful because, if not locked by the fibrous structure of the absorbent layer, the superabsorbent particulate material is pushed in the direction towards the wound bed.

[0316] The absorbent layer 450 may include a plurality of fiber layers. The fibers are strand-like and are preferably made from cellulose, polyester, viscose or the like. The dry absorbent particles are preferably distributed across the absorbent layer ready for use. In some embodiments, the absorbent layer includes a pad of cellulose fibers and a plurality of superabsorbent particles. In a further embodiment, the absorbent layer is a non-woven layer of randomly oriented cellulose fibers.

[0317] The superabsorbent particles / fibers may be, for example, sodium polyacrylate or carboxymethy cellulose materials, or any material having the ability to absorb many times its own weight in a liquid. In some embodiments, the material can absorb five times or more its own weight of 0.9% W / W physiological saline or the like. In some embodiments, the material can absorb 15 times or more its own weight of 0.9% W / W physiological saline or the like. In some embodiments, the material has the ability to absorb 20 times or more its own weight of 0.9% W / W physiological saline or the like. Preferably, the material has the ability to absorb 30 times or more its own weight of 0.9% W / W physiological saline or the like.

[0318] Preferably, the superabsorbent particles are very hydrophilic, grab the fluid when entering the coating material, and expand when contacted. An equilibrium is established within the coating core, whereby moisture passes from the superabsorbent to the dryer surrounding area, and when hitting the upper film, the film switches and fluid vapor begins to be generated. A moisture gradient is established within the coating material to continuously remove fluid from the wound bed and prevent the coating material from becoming heavy with exudate.

[0319] The absorbent layer 450 may include at least one through-hole. The through-hole can be positioned to be under the suction port described with reference to FIG. 12D. A single through-hole can be used to create an opening under the port 460 (not shown in FIG. 15B). It will be understood that a plurality of openings can alternatively be utilized. In addition, if two or more ports are to be utilized according to a particular embodiment of the present invention, one or more openings may be made in the superabsorbent layer in alignment with each port. Although not essential to a particular embodiment of the present invention, the use of through-holes in the superabsorbent layer provides a fluid flow path that is not particularly obstructed, which is useful in certain situations.

[0320] Using one or more through-holes in the absorbent layer also has the advantage that, when the absorbent layer 450 contains a gel-forming material such as a superabsorbent during use, no barrier generally forms that prevents further movement of liquid and movement of fluid when the material swells to absorb liquid. In this way, each opening in the absorbent layer provides a fluid path to the surface of the filter facing the wound between the lower permeable layer or spacer layer and the upper permeable layer or spacer layer, and then proceeds into the interior of the port.

[0321] These layers can be covered with a single-layer film or cover layer 430. The cover layer can include a filter that can be positioned over the absorbent layer, or the filter may be incorporated into the port 460, and is hereby incorporated by reference in its entirety as described in International Application Publication No. WO 2013 / 175306 A2, U.S. Publication No. US2011 / 0282309, and U.S. Publication No. 2016 / 0339158. As shown in FIG. 7A, the cover layer 430, which is gas-impermeable but moisture-permeable, extends across the width of the wound dressing. The cover layer may be similar to the cover layer or backing layer described with reference to FIGS. 12A-12D. For example, it may be a polyurethane film (e.g., Elastollan SP9109) having a pressure-sensitive adhesive on one side. The cover layer 430 is impermeable to gas and thus operates to cover the wound and seal the wound cavity in which the wound dressing is placed on top. In this way, an effective chamber is created between the cover layer and the wound site where negative pressure can be established. The cover layer 430 is sealed to the wound contact layer 440 within the boundary region 410 around the dressing, for example via an adhesive technique or a welding technique, to prevent air from being drawn into the boundary region. The cover layer 430 protects the wound from external bacterial contamination (bacterial barrier), allows liquid to move from the wound exudate through the layer, and evaporate from the outer surface of the film. The cover layer 430 typically includes two layers, namely a polyurethane film and an adhesive pattern spread over this film. The polyurethane film may be moisture-permeable and made of a material that has a high water permeability when wet.

[0322] The cover layer may include a gap within the cover layer to provide fluid communication with a negative pressure source or a pump. The filter may be disposed in communication with the gap of the wound cover 4430. The gap of the wound cover 430 may be covered by a port 460. In some embodiments, the port 460 is connected to a conduit for communicating with a negative pressure source or a pump. The port 460 may include a filter 420 provided to cover the gap of the cover layer 430. In some embodiments, the filter 420 may be integral with the port 460. The filter 420 may include a hydrophobic material for protecting the pump and / or other components from liquid exudate. The filter 420 may block fluid while allowing gas permeation. In some embodiments, the filter may be similar to the filters or filter systems described above with respect to FIGS. 12A-12D. In some embodiments, the gaps of the cover layer 430 and the port 460 provide fluid communication between the wound dressing and the pump. In some embodiments, the pump, electronics, switch, and battery can be located at a remote location from the dressing. In some embodiments, the pump, electronics, switch, and battery can be positioned on top of the first cover layer, and a second filter and a second cover layer can be used alternatively or additionally. For example, the second filter can be composed of an antibacterial and / or antimicrobial material so that the pump can discharge gas into the atmosphere. Also, the second filter can help reduce the noise generated by the pump.

[0323] If there is remaining free absorbent capacity in the dressing, the negative pressure may be lost at the wound bed. This can occur because some or all of the pores in the filter are blocked with liquid or particles. In some embodiments, a solution is utilized that allows the full capacity of the dressing absorbent layer to be utilized while maintaining an air pathway between the negative pressure source and the wound bed.

[0324] In a dressing embodiment that directly utilizes a cover layer over the absorbent layer, the dressing has voids under a filter that can be filled with liquid, thereby plugging the filter pores and preventing airflow to the wound bed. A spacer layer or a permeable layer 490 can be used to provide a fluid flow path above the absorbent layer 450 and prevent occlusion of the port 460. In some embodiments, the permeable layer 490 of the dressing can be provided both above and below the absorbent layer. The permeable layer is non-compressible and can maintain a path for fluid flow between the negative pressure source and the wound bed through the filter. In some embodiments, the permeable layer can enclose the absorbent layer or wrap around the absorbent layer, as shown in FIGS. 15A and 15B. The wrapped permeable layer can provide a continuous length of permeable material from the filter 420 to the wound bed. The permeable layer can cross the length of the topmost surface of the absorbent layer, wrap around at least one side of the absorbent layer, and cross the length of the bottom surface (the surface facing the wound) of the absorbent layer. In some embodiments, the permeable layer can wrap around two sides of the absorbent layer, as shown in FIG. 15A.

[0325] In some embodiments, the permeable layer can be utilized to distribute negative pressure over the wound site and assist in facilitating the transport of wound exudate and fluid into the wound dressing.

[0326] The lower portion of the permeable layer 490 of the porous material is located above the wound contact layer and below the absorbent layer and can wrap around the edge of the absorbent layer. When the permeable layer is wrapped around at least one edge of the absorbent layer, the permeable layer has an upper portion that can be positioned between the cover layer and the absorbent layer. As used herein, the edge of the absorbent layer or the dressing refers to the side surface of the material that is substantially perpendicular to the wound surface and extends along the height of the material.

[0327] In some embodiments, the permeable layer can be a porous layer. This spacer layer or permeable layer 490 allows a fluid containing liquid and gas to permeate away from the wound site and into the upper layer of the wound dressing, as described with reference to FIG. 12D. In particular, the permeable layer 490 ensures that the external air channel can be maintained to transmit negative pressure across the entire wound area, even when the absorbent layer has absorbed a significant amount of exudate. The layer should remain open under the normal pressure applied during negative pressure wound therapy, as described above, so that the entire wound site receives an equal negative pressure. The permeable layer 490 may be formed from a material having a three-dimensional structure. For example, a knitted or woven spacer fabric (e.g., a warp-knitted polyester such as Baltex 7970), or a non-woven fabric may be used. Other materials such as those described hereinabove can of course be utilized.

[0328] The wound dressing 400 may incorporate or include a loaded matrix as described above. For example, a loaded foam or fiber layer containing a powder charge / additive, as described and illustrated herein in FIGS. 1 - 10, may be incorporated within the wound dressing 400. In some embodiments, the loaded matrix layer may be provided under the permeable layer 490. In some embodiments, the loaded matrix layer may be provided over the wound contact layer 440. In some embodiments, the loaded matrix layer may replace all or part of the permeable layer 490, for example, such that the loaded matrix layer is wrapped around the edges of the absorbent layer 450 (described further below) and the wound contact layer 440. In some embodiments, the loaded matrix layer may complement or replace the absorbent layer 450, or alternatively, the absorbent layer 450 may be loaded with a powder charge as described above.

[0329] The loaded matrix layer can be configured to be flexible yet firm enough to withstand negative pressure so that the loaded matrix does not collapse excessively and thereby sufficiently transmits the negative pressure to the wound when the negative pressure is applied to the wound dressing 400. The loaded matrix layer can be configured to include pores in a sufficient number or size to allow for delivery of negative pressure therethrough. Further, the loaded matrix layer can have a thickness suitable for delivering sufficient negative pressure to the wound. For example, the loaded foam layer can have a thickness of 1 mm to 5 mm, 1.5 mm to 4 mm, or 2 mm to 3 mm. In some embodiments, the loaded matrix layer can have a thickness of approximately 2 mm.

[0330] By providing a permeable layer between the port and the absorbent layer, it is possible to prevent fluid or exudate removed from the wound from clogging the port and / or the filter within the port. There may be some free particles in the pores of the absorbent layer located below the filter. The free particles in the pores can gel and potentially clog the pores and / or the filter area. Thus, the upper permeable layer can keep the superabsorbent particles out of the filter and allow the dressing to be fully filled. In some embodiments, the permeable layer wound around the absorbent layer allows the port to be placed anywhere with respect to gravity. The permeable layer positioned above the absorbent layer can eliminate the concern that fluid or exudate removed from the wound will clog the port and / or the filter within the port of the section of the absorbent layer that is initially filled.

[0331] As shown in FIG. 15C, the wound dressing 300 may include a wound contact layer 322. The wound contact layer 322 may be similar to the wound contact layer 225 described with reference to FIG. 12D. In some embodiments, the wound contact layer 322 may be a double-sided coated (silicone-acrylic) perforated adhesive wound contact layer. The permeable layer 326a and the absorbent layer 321 may be provided in the same manner as the dressing described with reference to FIG. 12D, but the permeable layer 326a is on top of the absorbent layer. The wound dressing 300 may include a second permeable layer 326b between the absorbent layer and the backing layer on top of the absorbent layer. The first and second permeable layers 326a and 326b may contact the absorbent layer more than 5 mm around. This can be the reverse of the cut shape of the dressing as described above. In some embodiments, there are no through holes or gaps in the absorbent layer 321 or the second permeable layer 326b. In some embodiments, the holes in the absorbent layer are filled with superabsorbent particles or other materials, which may be disadvantageous because they may block the filter of the standard material dressing. The backing layer 320 is located on top of the second permeable layer 326b, and the backing layer includes an orifice 327 that allows connection of the fluid connector and can transmit negative pressure to the dressing. In some embodiments, the first and second permeable layers 326a, 326b may include a 3D fabric.

[0332] As described above, the wound dressing 300 may incorporate or include a loaded matrix. For example, as described hereinbefore and illustrated in FIGS. 1-10, a loaded foam or fiber layer containing a powder charge / additive may be incorporated within the wound dressing 300. In some embodiments, the loaded matrix layer may be provided under the first permeable layer 326a. In some embodiments, the loaded matrix layer may be provided on top of the wound contact layer 322. In some embodiments, the loaded matrix layer may be replaced by the first permeable layer 326a. In some embodiments, the loaded matrix layer may complement or replace the absorbent layer 321, or alternatively, the absorbent layer 321 may be loaded with a powder charge as described above.

[0333] The loaded matrix layer can be configured to be flexible yet firm enough to withstand negative pressure so that the loaded matrix does not collapse excessively and thereby sufficiently transmit negative pressure to the wound when negative pressure is applied to the wound dressing 300. The loaded matrix layer can be configured to include pores in a sufficient number or size to allow delivery of negative pressure therethrough. Further, the loaded matrix layer can have a thickness suitable for delivering sufficient negative pressure to the wound. For example, the loaded matrix layer can have a thickness of 1 mm to 5 mm, 1.5 mm to 4 mm, or 2 mm to 3 mm. In some embodiments, the loaded matrix layer can have a thickness of approximately 2 mm.

[0334] Multilayer wound dressing for NPWT including a shielding layer FIG. 16A illustrates a cross-section through a wound dressing 2100 similar to the wound dressings of FIGS. 12A-12D according to an embodiment of the present disclosure. Alternatively, the wound dressing 2100 can be any of the wound dressing embodiments disclosed herein, including but not limited to the wound dressing 110, or any combination of any number of features of the wound dressing embodiments disclosed herein, and can be placed over the wound site to be treated. The dressing 2100 can be arranged to form a sealed cavity over the wound site. In a preferred embodiment, the dressing 2100 includes a backing layer 2140 attached to a wound contact layer 2102 similar to the cover layer and wound contact layer described with reference to FIGS. 12A-12D. These two layers 2140, 2102 are preferably joined or sealed together to define an internal space or chamber. This internal space or chamber may be adapted to distribute or transmit negative pressure and store wound exudate and other fluids removed from the wound, and may include additional structures and other functions described herein. Examples of the following structures include a permeable layer 2105 and an absorbent layer 2110 similar to the permeable layer and absorbent layer described with reference to FIGS. 12A-12D.

[0335] The layer 2105 of the porous material can be placed above the wound contact layer 2102. This porous layer or permeable layer 2105 enables fluids, including liquids and gases, to permeate away from the wound site and into the upper layer of the wound dressing. In particular, it is preferred that the permeable layer 2105 ensures the maintenance of an external air channel such that a negative pressure is transmitted over the wound area even when the absorbent layer absorbs a significant amount of exudate. The layer 2105 should preferably remain open under the normal pressure that will be applied during negative pressure wound therapy, as described above, so that the entire wound site receives an equal negative pressure.

[0336] In some embodiments, the layer 2105 can be formed from a material having a three-dimensional structure. For example, knitted or woven spacer fabrics (e.g., cross-knitted polyester of Baltex 7970), or non-woven fabrics can be used.

[0337] The layer 2110 of the absorbent material is provided above the permeable layer 2105. An absorbent, which includes a foam or a natural or synthetic non-woven material and optionally a superabsorbent material, forms a reservoir for fluids, specifically the liquids removed from the wound site. In some embodiments, the layer 2100 may also help draw the fluid towards the backing layer 2140.

[0338] Referring to FIG. 16A, the masking layer or shielding layer 2107 can be positioned under at least a portion of the backing layer 2140. In some embodiments, the shielding layer 2107 can have any of the same features, materials, or other details of other embodiments of the shielding layers disclosed herein, including but not limited to having any visual windows or apertures. Examples of wound dressings having a shielding layer and a visual window are described in International Patent Publication No. WO2014 / 020440, which is incorporated herein by reference in its entirety. Further, the shielding layer 2107 can be positioned adjacent to the backing layer or adjacent to any other desired dressing layer. In some embodiments, the shielding layer 2107 can be adhered to the backing layer or formed integrally with the backing layer. The shielding layer 2107 preferably has substantially the same size and shape as the absorbent layer 2110 and is configured to cover it. Thus, in these embodiments, the shielding layer 2107 is a smaller area than the backing layer 2140.

[0339] The material of the absorbent layer 2110 can also prevent the liquid collected within the wound dressing 2100 from freely flowing within the dressing and preferably acts to contain any collected liquid within the absorbent layer 2110. The absorbent layer 2110 also helps to distribute the fluid throughout the layer by a suctioning action so as to draw the fluid from the wound site and store it across the absorbent layer. This aids in preventing agglomeration in the area of the absorbent layer. The capacity of the absorbent must be sufficient to manage the rate at which wound exudate flows when a negative pressure is applied. In use, the absorbent layer experiences a negative pressure, and thus the material of the absorbent layer is chosen to absorb liquid under such circumstances. For example, there are several materials, such as superabsorbent materials, that can absorb liquid when under a negative pressure. The absorbent layer 2110 may typically be manufactured from Freudenberg 114 - 224 - 4 of ALLEVYN™ foam and / or Chem-Posite™ 11C - 450. In some embodiments, the absorbent layer 2110 may include a composite material including superabsorbent powder, fibrous materials such as cellulose, and binder fibers. In a preferred embodiment, the composite material is an airlaid, thermally bonded composite material.

[0340] The orifice 2144 is preferably provided in the backing layer 2140 to enable application of a negative pressure to the covering material 2100. The suction port 2150 is preferably attached to or sealed over the orifice 2144 made in the covering material 2100 at the topmost part of the backing layer 2140 to transmit the negative pressure through the orifice 2144. A long tube may be connected to the suction port 2150 at the first end and to a pump unit (not shown) at the second end so as to enable pumping fluid from the covering material. The port may be adhered and sealed to the backing layer 2140 using an adhesive such as acrylic, cyanoacrylate, epoxy, UV curable or hot melt adhesive. The port 2150 is formed of a soft polymer such as polyethylene, polyvinyl chloride, silicone or polyurethane having a hardness of 30 to 90 on the Shore A scale. In some embodiments, the port 2150 may be made of a soft or conforming material.

[0341] Preferably, the absorbent layer 2110 and the shielding layer 2107 include at least one through-hole 2145 arranged to be under the port 2150. Of course, the respective holes through these various layers 2107, 2140, and 2110 may be of different sizes relative to each other. As shown in FIG. 16A, a single through-hole may be used to provide an opening under the port 2150. It will be understood that multiple openings may alternatively be utilized. Additionally, if two or more ports are to be utilized according to a particular embodiment of the present disclosure, one or more openings may be made in the absorbent and shielding layers in alignment with each port. Although not essential to a particular embodiment of the present disclosure, using through-holes in the superabsorbent layer may provide an unblocked fluid flow path, particularly when the absorbent layer 2110 is near saturation.

[0342] The gap or through-hole 2144 is preferably provided in the absorption layer 2110 and the shielding layer 2107 below the orifice 2144 such that the orifice is directly connected to the permeable layer 2105. Thereby, the negative pressure applied to the port 2150 can be transmitted to the permeable layer 2105 without passing through the absorption layer 2110. This ensures that when the absorption layer absorbs wound exudate, the negative pressure applied to the wound site is not inhibited by the absorption layer. In other embodiments, it may not be necessary to provide a gap in the absorption layer 2110 and / or the shielding layer 2107, or alternatively, a plurality of openings may be provided under the orifice 2144.

[0343] The backing layer 2140 preferably does not allow gas to pass through but allows water vapor to pass through and can extend across the width of the wound dressing 2100. For example, the backing layer 2140, which can be a polyurethane film (e.g., Elastollan SP9109) having a pressure-sensitive adhesive on one side, is impermeable to gas and thus serves to cover the wound and seal the wound cavity in which the wound dressing is placed on top. In this way, an effective chamber is created between the backing layer 2140 and the wound site where negative pressure can be established. The backing layer 2140 is preferably sealed to the wound contact layer 2102 within the boundary region 2200 around the dressing, for example, via an adhesion technique or a welding technique, so that air is not sucked into the boundary region. The backing layer 2140 protects the wound from external bacterial contamination (bacterial barrier), allows liquid from the wound exudate to move through the layer and evaporate from the outer surface of the film. The backing layer 2140 preferably comprises two layers, namely a polyurethane film and an adhesive pattern spread on this film. The polyurethane film is preferably moisture-permeable and can be manufactured from a material that has a high water permeation rate when wet.

[0344] In some embodiments, the absorbent layer 2110 may have an area larger than that of the permeable layer 2105 such that the absorbent layer overlaps the edge of the permeable layer 2105, thereby ensuring that the permeable layer does not contact the backing layer 2140. Thereby, an outer channel 2115 of the absorbent layer 2110 that directly contacts the wound contact layer 2102 is provided, which helps in more rapid absorption of exudate into the absorbent layer. Further, this outer channel 2115 ensures that liquid cannot be retained at the outer periphery of the wound cavity, which otherwise may seep out from the seal around the dressing and lead to the formation of leakage.

[0345] The wound dressing 2100 may incorporate or include a matrix as described above. For example, as previously described herein and illustrated in FIGS. 1 - 10, a loaded foam or fibrous layer containing powder charge / additives may be incorporated within the wound dressing 2100. In some embodiments, the loaded matrix layer may be provided under the permeable layer 2105. In some embodiments, the loaded matrix layer may be provided over the wound contact layer 2102. In some embodiments, the loaded matrix layer may be replaced with the permeable layer 2105 such that the loaded matrix layer is provided between the absorbent layer 2110 (described further below) and the wound contact layer 2102. In some embodiments, the loaded matrix layer may be the bottommost layer of the wound dressing 2100. The loaded matrix may have the same or substantially similar size and shape as the permeable layer 2105 and / or the absorbent layer 2110. In some embodiments, the loaded matrix layer may complement or replace the absorbent layer 2110, or the absorbent layer 2110 may be loaded with powder charge as described above.

[0346] The loaded matrix layer can be configured to be flexible yet rigid enough to withstand negative pressure so that the loaded matrix does not collapse excessively and thereby sufficiently transmit negative pressure to the wound dressing 2100 when negative pressure is applied to the wound. The loaded matrix layer can be configured to include pores in a sufficient number or size to allow for delivery of negative pressure therethrough. Further, the loaded matrix layer can have an appropriate thickness to transmit sufficient negative pressure to the wound. For example, the loaded matrix layer can have a thickness of 1 mm to 5 mm, 1.5 mm to 4 mm, or 2 mm to 3 mm. In some embodiments, the loaded matrix layer can have a thickness of approximately 2 mm.

[0347] FIG. 16B illustrates an embodiment of a wound dressing having a constricted portion, a shielding layer, and a viewing window. FIG. 16B shows a perspective view of an embodiment of the wound dressing 1400. The wound dressing 1400 preferably includes a port 1406. The port 1406 is preferably configured to be in fluid communication with a pump and can include a tube or conduit pre-attached to the port. Alternatively, negative pressure can be supplied to the wound dressing via other suitable fluid connectors including, but not limited to, the types of fluid connectors described hereinafter with reference to FIGS. 12A-12D.

[0348] The wound dressing 1400 may be configured similar to the embodiment of FIG. 16A above and may include an absorbent material 1402 below or within the backing layer 1405. Optionally, as described above with reference to FIG. 16A, the wound contact layer and the permeable layer may be provided as part of the wound dressing 1400. The absorbent material 1402 can include a narrowed central portion or constricted portion 1408 to improve the flexibility and conformability of the wound dressing to the skin surface. The backing layer 1405 may have a border region 1401 that extends beyond the perimeter of the absorbent material 1402. The backing layer 1405 may be a semi-transparent or transparent backing layer, and as a result, the border region 1401 created from the backing layer 1405 can be semi-transparent or transparent. The area of the interfacial region 1401 of the backing layer 405 can be made substantially equal around the entire dressing, except that the central portion is narrowed where the area of the border region is larger. It will be appreciated that the size of the border region 1401 depends on the overall dimensions of the dressing and other design choices.

[0349] As shown in FIG. 16B, a shielding layer 1404 having one or more viewing windows 1403 can be provided, optionally over or covering at least the absorbent layer 1402 and under the backing layer 1405. The shielding layer 1404 can partially or completely shield the contents (such as fluids) contained within the wound dressing 1400 and / or the absorbent material (i.e., within the absorbent material 1402 or under the backing layer 1405). The shielding layer can be a colored portion of the absorbent material or a separate layer covering the absorbent material. In some embodiments, the absorbent material 1402 can be hidden (partially or completely), colored, or tinted via the shielding layer 1404 to provide cosmetic and / or aesthetic improvements in a manner similar to that described above. Although other configurations are possible, the shielding layer is preferably provided between the top backing layer 1405 and the absorbent material 1402. The cross-sectional view of FIG. 16A illustrates this arrangement with respect to the masking or shielding layer 2107. Other layers and other wound dressing components can be incorporated into the dressing as described herein.

[0350] The shielding layer 1404 can be positioned at least partially over the absorbent material 1402. In some embodiments, the shielding layer 1404 may be positioned adjacent to the backing layer or adjacent to any other desired coating layer. In some embodiments, the shielding layer 1404 can be adhered to or integrally formed with the backing layer and / or the absorbent material.

[0351] As shown in FIG. 16B, the shielding layer 1404 can have a peripheral shape and size that is substantially the same as that of the absorbent material 1402. The shielding layer 1404 and the absorbent material 1402 can be of equal size such that the entire absorbent material 1402 can be shielded by the shielding layer 1404. The shielding layer 1404 can be capable of blocking wound exudate, blood, or other substances released from the wound. Further, the shielding layer 1404 can be completely or partially opaque while having a cut-out viewing window or perforations.

[0352] In some embodiments, the shielding layer 1404 can help reduce the unappealing appearance of the coating during use by using a material that adds partial shielding or masking of the coating surface. The shielding layer 1404 in one embodiment only partially shields the coating, allowing the clinician to access the required information by observing the spread of exudate across the coating surface. Due to the partial masking nature of this embodiment of the shielding layer, a skilled clinician can perceive the different colors caused by exudate, blood, by-products, etc. of the coating, enabling visual assessment and monitoring of the extent of spread across the entire coating. However, since the color change of the coating from its clean state to a state containing exudate is minimal, the patient is less likely to notice the aesthetic difference. Reducing or eliminating the visual indicator of wound exudate from the patient's wound is likely to have a positive effect on the patient's health, for example leading to a reduction in stress.

[0353] In some embodiments, the shielding layer can be formed from a non-woven fabric (e.g., polypropylene) and can be thermally bonded using a diamond pattern having a bonding area of 19%. In various embodiments, the shielding layer can be hydrophobic or hydrophilic. Depending on the application, in some embodiments, the hydrophilic shielding layer can further provide moisture permeability. However, in some embodiments, the hydrophobic shielding layer can still allow for better retention of dyes or colors within the shielding layer while providing sufficient moisture permeability (i.e., appropriate material selection, shielding layer thickness). In this way, the dye or color can be confined under the shielding layer. In some embodiments, this can enable the shielding layer to be colored a lighter color or white. In a preferred embodiment, the shielding layer is hydrophobic. In some embodiments, the shielding layer material can be sterilized using ethylene oxide. Other embodiments can be sterilized using gamma irradiation, electron beam, steam, or other alternative sterilization methods. Further, in various embodiments, the shielding layer can be colored or tinted, for example, in a medical blue color. The shielding layer can also be composed of multiple layers, including a colored layer laminated or fused to a stronger uncolored layer. Preferably, the shielding layer is odorless and exhibits minimal fiber shedding.

[0354] However, in some embodiments, the absorbent layer 1402 itself may be colored or dyed, such that a shielding layer is not necessary. The covering material may optionally include means for partially shielding the top surface. This can also be achieved using a textile (woven, knitted, or non-woven) layer without openings, if fluid evaporation from the absorbent structure is still to be enabled. Also, appropriate inks or color pad components (woven yarns, sewing threads, coatings) can be used respectively to print a shielding pattern on the top surface of the upper film or the topmost pad component. Another way to achieve this is to have a completely opaque top surface, which can be temporarily opened by a clinician to inspect the covering material state (e.g., through a window) and then closed again without compromising the wound environment. Further, FIG. 16B illustrates an embodiment of a wound dressing that includes one or more viewing windows 1403. The one or more viewing windows 1403 preferably extend through the shielding layer 1404. These viewing windows 1403 may enable visualization of wound exudate in the absorbent material under the shielding layer by a clinician or a patient. FIG. 16B illustrates an arrangement of dots (e.g., in one or more parallel rows) that can serve as viewing windows 1403 in the shielding layer 1404 of the wound dressing. In a preferred embodiment, two or more viewing windows 1403 may be parallel to one or more sides of the dressing 1400. In some embodiments, the one or more viewing windows can be measured in the range of 0.1 mm to 20 mm, preferably 0.4 mm to 10 mm, and even more preferably 1 mm to 4 mm. The viewing windows 1403 may be cut out through the shielding layer 1404 or may be part of an uncolored region of the shielding layer 1404, and thus may enable visualization of the absorbent material 1402. The one or more viewing windows 1403 may be arranged in a repeating pattern across the shielding layer 1404 or may be arranged randomly across the shielding layer. Further, the one or more viewing windows can be circular in shape or dots.Preferably, one or more visual inspection windows 1403 are configured to allow not only the degree of saturation but also the progression or diffusion of the fluid to the fluid port 1406 of the fluid. In some embodiments, the performance of the coating material may be adversely affected when the fluid level saturates the fluid near the port 1406. In some embodiments, the "star" arrangement of the visual inspection windows 1403 that appears around the port 1406 may be suitable for indicating this progression, although of course other configurations are possible. In some embodiments, the visual inspection window 1403 corresponds to the area of the absorbent material 1402 that is not covered by the shielding layer 1404. Therefore, the absorbent material 1402 is directly adjacent to the backing layer 1405 in this region. Since the shielding layer 1404 functions as a partial shielding layer, the visual inspection window 1403 can be used by a clinician or other trained user to evaluate the diffusion of wound exudate across the entire coating material. In some embodiments, the visual inspection window 1403 can include an array of dots or a crescent cutout. For example, the array of dots as the visual inspection window 1403 is illustrated in FIG. 16B, and the array of dots is arranged in a 5×2 array. Further, in some embodiments, the dot pattern can be evenly distributed across the entire shielding layer and across the entire surface or substantially the entire surface of the shielding layer. In some embodiments, the visual inspection window 1403 can be randomly distributed through the shielding layer. The area of the shielding layer 1404 not covered by one or more visual inspection windows 1403 preferably strikes a balance to minimize the appearance of exudate while allowing inspection of the coating material 1400 and / or the absorbent material 1402. In some embodiments, the area exposed by one or more visual inspection windows 1403 does not exceed 20%, preferably 10%, and even more preferably 5% of the area of the shielding layer 1404.

[0355] The viewing window 1403 can take several configurations. In some embodiments, the viewing window 1403 may include an array of uncolored dots (holes) made at regular intervals in the shielding layer 1404. Although the dots shown here are in a particular pattern, the dots may be arranged in different configurations or randomly. The viewing window 1403 is preferably configured to enable a patient or caregiver to check the state of the absorption layer, in particular to be able to determine its saturation level and the color of the exudate (e.g., whether there is excessive blood). By having one or more viewing windows, the state of the absorption layer can be determined in a non-aesthetically unpleasant and unobtrusive manner for the patient. Since most of the absorption layer may be shielded, the total amount of exudate may be hidden. Thus, the state and saturation level of the absorption layer 1402 can present a less obtrusive appearance so as to reduce the patient's embarrassment and visibility, thereby enhancing the patient's comfort. In some configurations, one or more viewing windows 1403 can be used to provide a numerical assessment of the saturation of the covering material 1400. This may be done electronically (e.g., via digital photo evaluation) or manually. For example, the saturation can be monitored by counting the number of viewing windows 1403 that can be blocked or colored by exudate or other wound fluids.

[0356] In some embodiments, the absorption layer 1402, or the shielding layer 1404, in particular the colored portion of the absorption layer, may include the presence of an auxiliary compound (or be colored thereby). The auxiliary compound may be activated carbon in some embodiments, which can act to absorb odors. The use of antibacterial, antifungal, anti-inflammatory, and other such therapeutic compounds is also possible. In some embodiments, the color may change as a function of time (e.g., to indicate that the covering material needs to be changed) when the covering material is saturated or when the covering material has absorbed a certain amount of harmful substances (e.g., to indicate the presence of infectious pathogens). In some embodiments, one or more viewing windows 1403 may be monitored electronically and used in conjunction with a computer program or system to alert the patient or physician of the saturation level of the covering material 1400.

[0357] Multi-layer wound dressing containing a retention layer Figure 17 shows an embodiment of a multi-layer wound dressing 3100. The wound dressing 3100 includes a liquid-impermeable film layer 3102 located at the top of the wound dressing 3100. In use, the film layer 3102 is the top layer of the wound dressing 3100 that is the most distal from the wound site. The film layer 3102 is also gas and vapor permeable and serves to allow evaporation of liquid or wound exudate from the wound dressing 3100 to prevent maceration of the wound. In this example, the film layer 3102 is formed from a polyurethane mixture, although other suitable materials may include other polymeric materials such as polyethylene or polypropylene.

[0358] The absorption layer 3108 is below the film layer 3102. The absorption layer 3108 has a fibrous structure for absorbing exudate from the wound site. In this example, the absorption layer 3108 includes superabsorbent fibers. The absorption layer 3108 also includes other fibers. In this example, the absorption layer includes superabsorbent fibers, viscose fibers, and polyester fibers. In this example, the absorption layer 3108 includes approximately 40% superabsorbent fibers, 40% viscose fibers, and 20% polyester fibers. In other embodiments, the absorption layer may include from about 0 to 50% superabsorbent fibers, 0 to 100% viscose fibers, and 0 to 50% polyester fibers. Suitable superabsorbent fibers include cross-linked acrylate copolymer fibers partially neutralized with sodium salts, although other superabsorbent fibers are also available. The absorption layer 3108 can be manufactured using a needling process in which the fibers are mechanically entangled together. In other embodiments, the absorption layer 3108 may include other ratios of superabsorbent fibers, viscose fibers, and polyester fibers. For example, the absorption layer may include approximately 50% superabsorbent fibers, 35% viscose fibers, and 20% polyester fibers. Alternatively, the absorption layer may include 40% superabsorbent fibers and 60% viscose fibers. The film layer 3102 is located on top of the absorption layer 3108 such that wound exudate collected within the absorption layer 3108 can evaporate from the wound dressing 3100 through the film layer 3102.

[0359] The retention layer 3106 is positioned between the film layer 3102 and the absorption layer 3108. The retention layer 3106 reinforces the structure of the absorption layer 3108, thereby helping to reduce the shrinkage of the wound dressing 3100. The retention layer 3102 also provides additional mechanical strength to the film layer 3102 and helps to reduce or prevent wrinkles in the film layer 3102 over time. The mechanical strength also reduces the likelihood that dressing deformation or roll-up will cause pressure points. Suitably, the retention layer 3106 is configured to have a tensile strength of 0.05 - 0.06 Nm and to provide mechanical strength to the surrounding layers (e.g., the film layer 3102 and the absorption layer 3108) without compromising the flexibility of the wound dressing 3100. The retention layer 3106 can have a thickness of 50 - 150 μm. Suitably, the retention layer 3106 can have a thickness of about 100 - 110 μm.

[0360] The wound dressing 3100 may incorporate or include a loaded matrix as described above. For example, as previously described herein and illustrated in FIGS. 1 - 10, a loaded foam or fibrous layer containing a powder charge / additive may be incorporated into the wound dressing 3100. In some embodiments, the loaded matrix layer may be provided under the cover layer 3102. In some embodiments, the loaded matrix layer may be provided under the absorption layer 3108. In some embodiments, the loaded matrix layer may be the bottommost layer of the wound dressing 3100. The loaded foam may have the same or substantially similar size or shape as the cover layer 3102 and / or the absorption layer 3108. In some embodiments, the loaded matrix layer may complement or replace the absorption layer 3108, or alternatively, the absorption layer 3108 may be loaded with a powder charge as described above.

[0361] Referring to FIG. 18, the retention layer 3106 includes a net 3200 configured to reduce the shrinkage of the wound dressing 3100. Suitably, the net 3200 is configured to reduce the shrinkage of the absorbent layer 3108 and / or the film layer 3102 and help reduce the wrinkles in the film layer 3102. In this example, the net 3200 has a substantially hexagonal (or honeycomb) structure 3204 that includes a plurality of substantially triangular-shaped gaps 3202 extending therethrough. The hexagonal structure 3204 is formed from a plurality of dots (or protrusions) 3206 joined by polymer strands 3208. The dots 3206 are substantially evenly spaced from each other via gaps. Each dot forms a vertex of a hexagonal pattern within the structure 3204. Each dot 3206 is joined by polymer strands 3208 to the six surrounding dots 3206. That is, six polymer strands 3208 extend from each dot 3206, each connecting to its respective surrounding dot 3206 to form a hexagonal structure 3204 having triangular gaps 3202 between the polymer strands 3208. Each of the triangular gaps 3202 may have an area A of from 0.005 to 0.32 mm2. This allows fluid and gas to pass freely through the gaps from the wound while providing sufficient strength to the retention layer 3106. The structure 3204 can also be said to be a structure that includes a plurality of strands or struts that form a plurality of triangles when joined. In this example, the triangles are arranged in a mosaic pattern. The strands or struts can be arranged in other forms, such as squares, diamonds, or rectangles of different geometric shapes and thus different open areas.

[0362] In this example, the retention layer 3106 is positioned directly adjacent to the absorbent layer 3108. Thus, the retention layer 3106 can effectively provide additional mechanical strength to the fibers at the top surface of the absorbent layer 3108. This can help prevent movement of the fibers and reduce shrinkage of the absorbent layer 3108. Appropriately, the retention layer 3106 is bonded to the fibers at the top surface of the absorbent layer 3108. This can help lock the fibers in place and prevent or reduce movement. In this example, the retention layer 3106 further includes a bonding layer for heat laminating the net 3200 to the absorbent layer 3108. Thus, the retention layer 3106 is heat laminated to the fibers of the absorbent layer 108 via the bonding layer.

[0363] The bonding layer contained within the net has a melting temperature lower than that of the net 3200 such that the retention layer 3106 can be heat laminated to the absorbent layer 3108 while maintaining the structure of the net 3200. The bonding layer may be formed from a low melting point polymer, such as low melting point ethylene vinyl acetate, and the net 3200 may be formed from high density polyethylene that melts at a higher temperature than the bonding layer. Other polymers having a melting point lower than that of the net 3200 may also be suitable. For example, the bonding layer may be a separate layer or, alternatively, may include an ethylene acrylate or thermoplastic polyurethane based adhesive. The net 3200 and the adhesive layer may be coextruded to form the retention layer 3106. Appropriately, the bonding layer is extruded in a similar structural shape to the net 3200 such that the gaps 3202 within the net 3200 are not blocked by the bonding layer. This helps ensure that exudate from the absorbent layer 3108 passes through the retention layer and evaporates from the wound dressing 3100 through the film layer 3102.

[0364] Figures 19A - 19B show another example of the multilayer wound dressing 3300. The wound dressing 3300 includes a film layer 3302, a holding layer 3306, and an absorption layer 3308, which are the same as the film layer 3102, the holding layer 3106, and the absorption layer 3108 described in relation to FIG. 17. Also, the wound dressing 3300 includes a first adhesive layer 3304 located between the film layer 3302 and the holding layer 3306 to attach the film layer 3302 to the holding layer 3306. The first adhesive layer 3304 is a hot melt adhesive applied to the wound-facing surface (lower side) of the film layer 3302. Appropriately, the first adhesive layer 3304 is pattern-coated on the film layer 3302 to include pores so that gas and liquid-vapor can pass through the pores in the first adhesive layer 3304. In other examples, the film layer 3302 may be directly laminated (e.g., heat-laminated) on the holding layer 3306 without the need for an adhesive layer 3304 therebetween. In this example, the wound dressing 3300 also includes a foam layer 3312 that is a fluid transport layer. The foam layer 3312 is located under the absorption layer 3306. The foam layer 3312 serves to draw fluid from the wound site and transport the fluid to the absorption layer 3308. The foam layer may be formed from open-cell polyurethane foam, as recognized by those skilled in the art, and other methods are also possible.

[0365] The adhesive web layer 3310 is located between the foam layer 3312 and the absorption layer 3108 and adheres the foam layer 3312 to the absorption layer 3308. The adhesive web layer can be formed from a two-component polypropylene / polyethylene fiber. Such two-component fibers are known in the art and will not be described in detail for the sake of brevity. The adhesive web layer 3310 includes a plurality of gaps extending therethrough, thereby allowing the passage of exudate from the foam layer 3312 to the absorption layer 3108.

[0366] The wound dressing 3300 also includes a wound contact layer 3320 that includes a perforated film 3316. The perforated film 3316 is located under the foam layer 3312 and helps prevent the wound dressing 3100 from adhering to the wound as the wound heals. For example, if the wound dressing 3300 includes a foam layer 3112, the perforated film 316 may prevent new tissue from growing within the foam layer 3312. In other examples, there may be no foam layer 3312, but the perforated film 3316 may help prevent the absorbent layer 3308 from being embedded within the wound. The perforations in the perforated film 3316 are preferably of a suitable size that is substantially uniformly distributed and allows exudate to pass through to the wound dressing 3300, for example, having holes with a diameter of 1 to 2.5 mm. Suitably, the perforated film 3316 is formed from polyurethane. Also, the wound contact layer 3320 may include an adhesive 3318 located under the perforated film 3316 (i.e., on the surface of the perforated film 3316 facing the wound) to adhere the wound dressing 3300 to the skin. In this case, the adhesive is silicone 3318 and preferably spreads over the underside of the perforated film having a coat weight of about 30 to 200 g / m 2 In some other embodiments, additional attachment elements such as, for example, a bandage, a strip of tape, or a compression bandage may be used to secure the wound dressing 3300 to the patient.

[0367] The upper side of the perforated film 3316 (i.e., the distal side from the wound) may be coated with a further adhesive layer 3314. The further adhesive layer 3314 adheres the wound contact layer 3320 to the foam layer 3312. Suitably, the further adhesive layer 3314 may be an acrylic adhesive, although other suitable adhesives may also be used. In other examples, the wound contact layer 3320 may be directly laminated (e.g., heat laminated) to the foam layer 3312 without the need for a further adhesive layer 3314 therebetween.

[0368] The wound dressing 3300 may incorporate or contain the loaded matrix as described above. For example, as previously described herein and as shown in FIGS. 1-10, a loaded foam or fiber layer containing a powder charge / additive may be incorporated within the wound dressing 3300. In some embodiments, the loaded matrix layer may be provided under the cover layer 3302. In some embodiments, the loaded matrix layer may be provided between the absorbent layer 3308 and the wound adhesive layer 3320. In some embodiments, the loaded matrix layer is provided between the foam layer 3312 and the wound contact layer 3320 and may thus be adhered to the contact layer 3314. In some embodiments, the loaded matrix layer may be supplemented or replaced by the absorbent layer 3308 and / or the foam layer 3312, or the absorbent layer 3308 and / or the foam layer 3312 may be loaded with a powder charge as described above. The loaded matrix may have the same or substantially similar size and shape as the cover layer 3302 and / or the absorbent layer 3308.

[0369] In another example, as shown in FIG. 20, the film layer 3502 may have a larger surface area than the remainder of the wound dressing 3500 so as to extend further outwardly than the other layers of the wound dressing. The wound-facing surface (underside) of the film layer may be coated with a pressure-sensitive adhesive 3504 (or other suitable adhesive) for attaching the dressing to the patient around the perimeter of the wound. The pressure-sensitive adhesive 3504 may also adhere the film layer 3502 to the retention layer 3506 of the wound dressing 3500. Also, the wound dressing may include an absorbent layer 3508, an adhesive web layer 3510, a foam layer 3512, a further adhesive layer 3514, and a wound contact layer 3520. Each layer of this example may be similar to the corresponding layer described above in connection with FIGS. 19A and 19B and thus, for the sake of brevity, will not be described in detail repeatedly.

[0370] In a further example, as shown in FIG. 21, both the wound contact layer 3620 and the film layer 3602 may extend beyond the remaining layers of the wound dressing 3600. The wound contact layer 3620 and the film layer may be adhesively bonded together around the periphery such that the remaining layers of the wound dressing are sandwiched between the wound contact layer 3620 and the film layer 3602 (e.g., via the adhesive layer 3604). In other words, the retention layer 3606, the absorbent layer 3608, the adhesive web layer 3610, and the foam layer 3612 may be encapsulated within the recess 3622 between the film layer 3602 and the wound contact layer 3620. In this example, an additional adhesive layer 3614 bonds the foam layer 3612 to the wound contact layer 3620, although in other embodiments the additional adhesive layer 614 may not be required. Each layer of this example may be similar to the corresponding layer described above in connection with FIGS. 19A and 19B and, thus, for the sake of brevity, will not be described in detail again.

[0371] The wound dressing 3600 of this example may be manufactured in the same manner as the wound dressing 3300, except that the film layer 3602 and the wound contact layer 3620 are laminated together around the periphery (e.g., via the adhesive layer 3604), sandwiching the remaining layers between the film layer 3602 and the wound contact layer 620. Alternatively, the film layer 3602 may be directly laminated (e.g., heat laminated) around the periphery to the wound contact layer 3620 without the need for an additional adhesive layer 3604.

[0372] In a manner similar to the wound dressing 3300 described in connection with FIGS. 19A-19B, the wound dressings 3500 and 3600 may incorporate or include a loaded matrix as described above. For example, as previously described herein and as illustrated in FIGS. 1-10, a loaded foam or fibrous layer containing a powder charge / additive may be incorporated within the wound dressings 3500 and 3600. For example, a loaded matrix layer may be provided between an absorbent layer and a wound adhesive layer. In some embodiments, the loaded matrix layer is provided between a foam layer and a wound contact layer and may thus be adhered to the contact layer. In some embodiments, the loaded matrix layer may be supplemented or replaced by the absorbent layer 3508 and / or the foam layer 3512, or alternatively, the absorbent layer 3508 and / or the foam layer 3512 may be loaded with a powder charge as described above. The loaded foam may have the same or substantially similar size and shape as the cover layer, the absorbent layer, and / or the foam layer 3312.

[0373] The wound dressings 3300, 3500, 3600 are described as having several adhesive layers, although one or more of these layers may be absent. For example, the perforated film itself may be formed from a hot melt adhesive material such that it can be heat laminated onto the foam layer, in which case no additional adhesive layer may be required. In another example, the adhesive web layer may be absent where the foam and absorbent layers are adhered together in another way. For example, the foam and absorbent layers may be directly chemically bonded together. Similarly, the first adhesive layer may not be necessary. For example, where the retention layer contains an adhesive material, or where the film layer itself is formed from a hot melt adhesive, the film layer and the retention layer may be directly adhered together.

[0374] In another example, the wound dressing may be provided without a foam layer. The foam layer serves to move exudate away from the wound. However, in some cases, depending on the severity of the wound, the absorbent layer may be able to sufficiently draw exudate from the wound without the need for a foam layer.

[0375] In the above-described embodiments, the retention layer is thermally laminated to the absorbent layer via the bonding layer, although other lamination techniques may be appropriate. For example, the bonding layer may include a pressure-sensitive adhesive. In this case, heat may not be required to laminate the retention layer and the adhesive layer together.

[0376] In the above example, the net layer is described as having a substantially hexagonal structure, although other geometric structures may be appropriate. Also, in other geometric structures, the gaps may have different geometric shapes.

[0377] In another embodiment, the wound dressing may include a plurality of retention layers to provide retention to other layers in the wound dressing. For example, a first retention layer may be located between the liquid-impermeable film layer and the absorbent layer, and a further retention layer may be located between the absorbent layer and the fluid transport layer (foam layer). This can help hold the absorbent layer from both sides and further reduce shrinkage of the absorbent layer.

[0378] Any of the examples described herein may be adapted for use in a negative pressure system (also referred to as a vacuum-assisted closure system) that includes a negative pressure source such as a negative pressure pump. For example, the film layer may include a negative pressure interface such as a port to which a negative pressure supply tube can be connected. The supply tube can be connected to the negative pressure source such that, in use, the negative pressure source applies a negative pressure to the wound dressing between the film layer and the wound to help draw wound exudate from the wound into the absorbent layer of the dressing.

[0379] The term Depending on the embodiment, any particular operation, action, event, or function of any of the processes described herein may be performed in a different order and, overall, may be added, incorporated, or excluded (e.g., not all are necessary for the practice of the process). Further, in certain embodiments, operations, actions, functions, or events may be performed simultaneously rather than sequentially, for example, through multi-threaded processing, interrupt processing, or across multiple processors or processor cores, or on other parallel architectures.

[0380] The processing of the various components of the illustrated system can be distributed across multiple machines, networks, and other computing resources. Further, two or more components of the system can be combined into fewer components. The various components of the illustrated system can be implemented in one or more virtual machines rather than in dedicated computer hardware systems and / or computing devices. Similarly, the illustrated data repositories can represent physical and / or logical data storage, including, for example, a storage area network or other distributed storage system. Further, in some embodiments, the connections between the shown components indicate the path of data flow rather than the actual connections between hardware. Further, in some embodiments, the connections between the illustrated components represent possible paths of data flow rather than actual connections between hardware.

[0381] Although some examples of possible connections are shown, any of the subsets of the illustrated components can communicate with any other subset of the components of the various implementations. The above patents and applications and other references, including those that may be described in the accompanying application documents, are incorporated herein by reference.

[0382] Features, substances, characteristics, or groups described in connection with a particular aspect, embodiment, or example are to be understood as applicable to any other aspect, embodiment, or example described herein, unless they are incompatible therewith. All features disclosed in this specification (including any appended claims, abstract, and drawings), or similarly all steps of any method or process disclosed, may be combined in any combination, except combinations where at least some of such features or steps are mutually exclusive. What the present invention protects is not limited to the details of any of the foregoing embodiments. What is protected extends to any novel one of the features disclosed in this specification (including any appended claims, abstract, and drawings), or any novel combination thereof, or similarly to any novel one of the steps of any method or process disclosed, or any novel combination thereof.

[0383] Although specific embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of protection. In fact, the novel methods and systems described herein may be embodied in various other forms. Further, various omissions, substitutions, and modifications may be made in the forms of the methods and systems described herein. Those skilled in the art will recognize that, depending on the embodiment, the actual steps performed in the illustrated or disclosed process may differ from the steps shown in the figures. Depending on the embodiment, certain of the steps described above may be removed and others may be added. For example, the actual steps or the order of steps performed in the disclosed process may differ from that shown in the figures. Depending on the embodiment, certain of the steps described above may be removed and others may be added. Further, the features and characteristics of the specific embodiments disclosed above may be combined in various ways to form additional embodiments, all of which will fall within the scope of the present disclosure.

[0384] This disclosure includes specific embodiments, examples, and applications, but the disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments or uses and their obvious modifications and their equivalents, and includes embodiments that do not necessarily provide all of the features and advantages described herein, as will be understood by those skilled in the art. Accordingly, the scope of the disclosure is not intended to be limited by the embodiments, but may be defined by the claims presented herein or hereafter presented.

[0385] Unless otherwise specifically recited or otherwise construed within the context of its use, conditional language such as “can,” “could,” “might,” or “may” is generally intended to convey that a particular embodiment includes a particular feature, element, or step while other embodiments do not. Thus, such conditional language is not necessarily intended to imply that a feature, element, or step is required in any way for one or more embodiments, or that logic for determining whether such a feature, element, or step is included in or should be performed in a particular embodiment, with or without user input or instruction, is necessarily included in one or more embodiments. Terms such as “comprising,” “including,” and “having” are synonyms and are used in an inclusive, non - limiting fashion and do not exclude additional elements, features, acts, and operations, etc. Also, the term “or” is used in an inclusive sense (and not an exclusive sense) such that when used, for example, to connect a list of elements, it means one, some, or all of the recited elements. Similarly, the term “and / or” with respect to the listing of two or more items encompasses all of the following interpretations of the words: any one of the items in the listing, all of the items in the listing, and any combination of the items in the listing. Further, the term “each,” as used herein, in addition to having its ordinary meaning, can also mean any subset of a series of elements to which the term “each” applies. Additionally, as used herein, “herein,” “above,” “below,” and similar words, when used in this application, mean the entire specification and not a particular portion of the specification.

[0386] Conjunctive phrases such as the phrase "at least one of X, Y, and Z" are to be interpreted separately, along with the context in which they are commonly used to convey that an item, term, etc. can be either X, Y, or Z, unless specifically stated otherwise. Thus, such conjunctive phrases do not normally imply that a particular embodiment requires it to include at least one of X, at least one of Y, and at least one of Z.

[0387] Expressions indicating the degree used herein, such as the terms "about", "approximately", "generally", and "substantially" used herein, represent values, amounts, or characteristics that are close to a predetermined value, amount, or characteristic that still performs the desired function or yields the desired result. For example, the terms "about", "approximately", "generally", and "substantially" can mean amounts within less than 10%, less than 5%, less than 1%, less than 0.1%, and less than 0.01% of a predetermined amount. As another example, in certain embodiments, the terms "generally parallel" and "substantially parallel" mean values, amounts, or characteristics that deviate from a perfectly parallel state by 15 degrees or less, 10 degrees or less, 5 degrees or less, 3 degrees or less, 1 degree or less, or 0.1 degree or less.

[0388] Any of the embodiments described herein can be used with or without a canister. Any of the coating material embodiments described herein can absorb and retain wound exudate.

[0389] The scope of the present disclosure is not intended to be limited by the description of specific embodiments and may be defined by the claims. The language of the claims should be interpreted in a broad sense based on the language used in the claims and is not limited to the examples described herein or the examples described during the prosecution of this application, and those examples should be construed as non-exclusive. [Additional Note 1] A material that is a wound care material, including a flexible hydrophilic polymer foam or fiber matrix having a network of cells with a cell network surface facing the wound surface and the back surface, or two surfaces facing the wound, and a structural matrix framework defining a network of pores or cell openings therein; and a powder charge containing a wound dressing additive or a combination thereof, wherein the matrix provides a meandering pore network, and the powder charge is contained on the surface facing the wound or the back surface and in the cell network in the cells proximal to the surface, more specifically, in an amount that decreases as the depth in the network increases. [Additional Note 2] The material according to Additional Note 1, wherein the wound dressing additive or a combination thereof is selected from any of the antibacterial species-releasing additives defined above or below, and antibacterial agents, bacteria, bacteriostatic agents, refractory materials, odor control such as activated carbon or bentonite, protein destruction or denaturation, absorption, conduction, structural support, absorbents such as superabsorbent polymers (SAP), color or color masking such as prevention of yellowing of PU foam (fluorescent dyes, antioxidants). [Additional Note 3] The material according to Additional Note 1 or 2, wherein the powder charge is present on one or both of the surfaces and is not present in the cell network and the structural matrix framework, or is present in an incidental or small amount. [Additional Note 4] The material according to any one of Additional Notes 1 to 3, wherein the powder charge is present on one or both of the surfaces and in the cell network proximal to the surface or the plurality of surfaces, and is not present in the structural framework, or is present in an incidental or small amount. [Additional Note 5] The powder charge is present (asymmetrically) in both of the surfaces and in the cell network proximal to one of the release surfaces, and is not present or is present in an incidental amount in the cell network proximal to the back surface and the structural framework, the material according to any one of dependent claims 1 to 2 and 4. [Dependent claim 6] The powder charge is loaded asymmetrically or is loaded with a decreasing amount as the depth in the matrix increases, the material according to any one of dependent claims 1 to 2 and 4 to 5. [Dependent claim 7] The powder charge is at 5% to 50% of the separation between the surfaces from the release surface or each of the release surfaces, for example, extending inward from the surface or the plurality of surfaces to a diameter of cells with an average size of 2 to 6, the material according to any one of dependent claims 1 to 2 and 4 to 6. [Dependent claim 8] The material according to any one of dependent claims 1 to 7, comprising a powder charge or a plurality of powder charges, which together or individually contain an antibacterial additive and a superabsorbent polymer (SAP). [Dependent claim 9] The material according to any one of dependent claims 1 to 8, comprising a powder charge or a plurality of powder charges, which contain an antibacterial additive or SAP together with a wound dressing additive as defined in claim 3, and the plurality of powder charges are contained in the same or different surfaces and / or in the cell network proximal thereto. [Dependent claim 10] The matrix contains the same or different additives impregnated with a background content or supplementary content in the structural matrix framework, the background content or supplementary content being contained in the preformed matrix, the material according to any one of dependent claims 1 to 9. [Dependent claim 11] The material according to any one of dependent claims 1 to 10, formed as a laminate with one or more powder charge holding fluid-permeable nets. [Dependent claim 12] The matrix or a part thereof contains a foam matrix selected from natural and synthetic polymer foams such as polystyrene, styrene-based copolymers, polyvinyl chloride, polyvinyl alcohol, polyurethane, phenolic polymers, silicone, polyolefins, rubber and elastomer thermoplastic polymers and combinations and copolymers thereof, the material according to any one of dependent claims 1 to 11. [Dependent claim 13] The material according to any one of appended claims 1 to 12, wherein the matrix or a part thereof comprises a fiber matrix selected from woven and non-woven fiber matrices of cellulose, alginic acid, chitin, chitosan, rayon and viscose and their functional derivatives, and mixtures thereof. [Appended claim 14] The material according to any one of appended claims 1 to 13, wherein the antibacterial atomic species releasing additive is selected from silver element, silver salts, silver complexes and their cage forms, and combinations thereof. [Appended claim 15] The material according to any one of appended claims 1 to 14, wherein the antibacterial atomic species releasing additive is selected from silver sulfadiazine, silver zeolite, silver sulfate, silver carbonate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate and combinations thereof. [Appended claim 16] The material according to any one of appended claims 1 to 15, wherein the two atomic species comprise iodine, such as caged iodine like cadexomer iodine. [Appended claim 17] The material according to any one of appended claims 1 to 16, wherein the superabsorbent polymer is selected from sodium polyacrylate, cross-linked CMC or cellulose derivatives functionalized with other absorbents (by carboxylation or sulfonation), cross-linked polyethylene oxide and PVA copolymers. [Appended claim 18] The material according to any one of appended claims 1 to 17, comprising an additive having a particle size of about 1 micron < D90 < 30 microns ~ D50 < 10 microns. [Appended claim 19] The material according to any one of appended claims 1 to 18, wherein the powder charge is selected from stearates, clays, silica, carbon or graphite and combinations thereof, and comprises a fluidizing agent having a particle size less than the additive particle size. [Appended claim 20] On the matrix surface and / or within the cell network, together with the powder charge, as part of the powder charge, or in solid melt or partial melt, a water permeability enhancer and / or binder selected from PEG, PVP and superabsorbent polymers as defined in appended claim 18, the material according to any one of appended claims 1 to 19. [Appended claim 21] A material which is a composite of matrix components, A flexible hydrophilic polymer foam or fiber matrix comprising two matrix surfaces providing a wound front and back surface, or two release surfaces, and between them a structural matrix framework defining a network of cells having a cell network surface and a network of pores or cell openings therein. An additive or powder pharmaceutical ingredient comprising an additive selected from an antibacterial additive, a wound care additive, and a wound dressing additive, wherein the material or the powder pharmaceutical further comprises a lubricant and / or a bulking agent and / or a binder, wherein the additive and the lubricant and / or the bulking agent and / or the binder are disposed together, or the powder pharmaceutical ingredient is disposed together on one or both of the release surfaces or the surfaces and / or within the cell network, preferably, the additive and / or the lubricant are partially embedded and held within the surface or the plurality of surfaces and the cells by the melted and softened bulking agent and / or binder disposed together, a material. [Article 22] A method for manufacturing the material according to any one of Articles 1 to 21. [Article 23] A flexible hydrophilic polymer foam or fiber matrix component comprising two matrix surfaces providing a release surface and a back surface, or two release surfaces, and between them, a network of cells having a cell network surface and a structural matrix framework defining a network of pores or cell openings therein, A powder pharmaceutical ingredient comprising an antibacterial species-releasing additive, wherein the species is selected from one or more antibacterial atomic species and one or more antibacterial diatomic species, a method for manufacturing a material comprising the same, wherein the method comprises providing the matrix component, providing the powder pharmaceutical ingredient, contacting the powder pharmaceutical ingredient with the matrix component, wherein the contacting comprises directing the powder pharmaceutical onto one or both of the release surfaces and / or into the cell network proximal to the surface or the plurality of surfaces, a method. [Article 24] A flexible hydrophilic polymer foam or fiber matrix component comprising a surface facing a wound and a back surface, or two surfaces facing a wound, and between them, a network of cells having a cell network surface and a structural matrix framework defining a network of pores or cell openings therein, A powder pharmaceutical ingredient comprising a wound dressing additive or a combination thereof, wherein the matrix provides a meandering pore network, a method for manufacturing a wound care material comprising the same, wherein the method comprises providing the matrix component, providing said powder charge component; contacting said powder charge component with said matrix component; directing said powder charge onto the face facing the wound or the back face and in said cell network in cells proximal to said face, in an amount decreasing as the depth within said network increases; a method comprising. [Claim 25] [Claim 23 or 24] A method according to claim 23 or 24, comprising melting and softening a binder provided with the matrix and / or with the fluid permeable laminated net lay-up on said face and / or with said powder charge as defined in any of claims 1 to 22 in a preceding, simultaneous or subsequent step, thereby embedding or binding said powder charge in said matrix face and / or in said cell network. [Claim 26] providing said matrix component or intermediate surface in a desired orientation, e.g. horizontal or inclined relative to the administration face, upwardly or downwardly; providing said powder charge in one or more hoppers, canisters, cassettes, nozzles or discharge buckets; directing said powder charge by administering it directly onto said matrix face or indirectly onto said intermediate surface and then contacting said matrix face with any such intermediate surface; a method according to any of claims 23 to 25, wherein administering comprises selecting from dusting, powder spreading, powder spraying, powder injection or deposition. [Claim 27] [Claim 23 to 26] A method according to any of claims 23 to 26, comprising preparing said powder charge, including selecting an additive, and any fluidizing agent, extender and / or binder, and their respective amounts, in view of the additive particle size and its required availability, and combining with any blend or mixture and providing in said powder charge for contacting and directing as claimed, said step additionally comprising subjecting said additive or said powder charge to a particle size selection process including sieving or mass separation or a particle size reduction process including atomization. [Claim 28] On one of said surfaces and into said cell network, directly or indirectly administering a powder charge and applying a translational force simultaneously or thereafter, thereby causing at least a part thereof to translate within said cell network, the method according to any one of appended claims 23 to 27. [Appended claim 29] The translational force includes a physical force directly applied to the powder charge such as needling, or indirectly applied to the powder charge through the matrix by, for example, mangling or rolling the matrix, thereby displacing the powder charge by translational movement such as by gravity or suction, the method according to any one of appended claims 23 to 28. [Appended claim 30] The translational force is applied to the entire matrix to which the powder charge has been administered or is to be administered, includes a field that fluidizes the powder charge or in which the powder charge is arranged to take a fluid such as a flow, and the field is selected from an alternating electrostatic field (AC electric field), a sound field, an ultrasonic field, an aeraulic field, an air field, etc., the method according to any one of appended claims 23 to 29. [Appended claim 31] In a further step, differentiating the powder charge portion on the surface and the powder charge portion within the cell network for each first availability and second availability so as to manipulate the respective amounts thereof and the distance that the second available portion is directed into said cell network and / or towards said back surface or second release surface, the method according to any one of appended claims 23 to 30. [Appended claim 32] A material obtained or obtainable by the method according to any one of appended claims 22 to 31. [Appended claim 33] An apparatus applied to a site and activated by contact with an aqueous medium provided at the site, the apparatus comprising (a) a site contact surface or layer and / or (b) an opposing non-site contact surface or layer, together with (c) an aqueous medium absorption layer included between or in combination with (a) and / or (b), (c) comprising a material according to any one of appended claims 1 to 21 or 32. [Appended claim 34] An apparatus including a wound dressing or a part thereof, applied to a wound site such as wound exudate and activated by contact with a fluid at the wound site, (a) a wound contact surface or layer and / or (b) an opposing non-wound contact surface or layer, together with (c) includes one or more optional fluid absorption layers included between them, or in combination with one of them, An apparatus, wherein (c) includes the antibacterial material or wound care material according to any one of claims 1 to 24 or 35. [Claim 35] The antibacterial apparatus according to any one of claims 33 and 34, wherein layer or surface (a) is an adhesive or a conformable non-adhesive film having elastic gaps. [Claim 36] The antibacterial apparatus according to any one of claims 33 to 35, wherein layer or surface (b) is a preferably conformable continuous vapor permeable polymer film that enables fluid and air regulation at the site and provides an antibacterial barrier. [Claim 37] The antibacterial apparatus according to any one of claims 33 to 36, including an additional layer selected from a masking layer (b') included between layer (b) and layer (c), and a superabsorbent layer (b'') included between layer (b) and layer (c). [Claim 38] The antibacterial material or apparatus according to any one of claims 1 to 21 and 32, or 33 to 37, which is sterilized, terminally sterilized and / or moisture-sealed and / or microbe-impermeable packaging. [Claim 39] A method for manufacturing the apparatus according to any one of claims 33 to 38. [Claim 40] A method of treating a site to make or keep the site free of microorganisms harmful to the health of the site, the method including contacting the site with the antibacterial material or apparatus according to any one of claims 1 to 22 and 32 or 33 to 38, thereby enabling the release of antibacterial species to the material and / or the site. [Claim 41] The method according to claim 40, which enables the treatment of a wound site and thereby the release of antibacterial species at a high concentration and at a high speed to the wound site with its continuous release for a required period. [Claim 42] A method for wound care, including contacting a wound site with the wound care material or apparatus according to any one of claims 1 to 22 and 32 or 33 to 38. [Claim 43] For use selected from the management of wounds, hygiene and sterilization of articles including medical and dental articles and in-use sterilization, hygiene and sterilization of personal care articles such as napkins, diapers, cosmetics and articles, hygiene and sterilization of food or fluids including air and water, or systems for their preparation and production such as food preparation or packaging plants, ventilation systems, water management systems, and in particular such use for preventing or defending against microbial infections is particularly beneficial, a material or device according to any of appended claims 1 to 22 and 32 or 33 to 38. [Appended claim 44] A method of treating a wound, comprising placing a wound dressing comprising a loaded wound dressing layer into or onto the wound, the loaded wound dressing layer comprising a porous matrix and a powder charge of an antibacterial release additive loaded within the matrix, the powder charge being concentrated at least on the surface of the porous matrix facing the wound, wherein the antibacterial release additive is activated to release an antibacterial agent from the wound dressing to the wound upon contact with a wet or aqueous medium. [Appended claim 45] The method according to appended claim 44, further comprising releasing the antibacterial agent for longer than one day. [Appended claim 46] The method according to appended claim 44 or 45, further comprising releasing the antibacterial agent releasing agent in an amount of up to 1.8 mg / cm 2 per day. [Appended claim 47] The method according to any of appended claims 44 to 46, further comprising contacting wound exudate with the loaded wound dressing layer before at least a portion of the antibacterial agent is released towards the wound, the antibacterial agent being configured to diffuse into the wound exudate upon contact with the wound exudate. [Appended claim 48] The method according to any of appended claims 44 to 47, further comprising applying a negative pressure to the wound dressing. [Appended claim 49] The method according to any of appended claims 44 to 48, wherein the antibacterial release additive is selected from the group consisting of silver element, silver salts, silver complexes, their cage forms, cage forms of iodine, and combinations thereof. [Appended claim 50] The method according to any of appended claims 44 to 49, wherein the antibacterial release additive is selected from the group consisting of silver sulfadiazine, silver zeolite, silver carbonate, silver sulfate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate, cadexomer iodine, and combinations thereof. [Appended claim 51] The method according to any one of appended claims 44 to 46, wherein the antibacterial agent contains silver ions. [Appended claim 52] The method according to any one of appended claims 44 to 46, wherein the antibacterial agent contains iodine. [Appended claim 53] The method according to any one of appended claims 44 to 52, wherein the powder charge of the antibacterial additive further contains a superabsorbent polymer. [Appended claim 54] The method according to any one of appended claims 44 to 53, wherein the powder charge of the antibacterial release additive has a particle size of about 1 micron < D90 < 30 microns ~ D50 < 10 microns. [Appended claim 55] The method according to any one of appended claims 44 to 54, wherein the powder charge of the antibacterial additive further contains a fluidizing agent selected from the group consisting of stearates, clays, silica, carbon, graphite and combinations thereof, and the fluidizing agent has a particle size smaller than that of the antibacterial release additive. [Appended claim 56] The method according to any one of appended claims 44 to 55, wherein the wound dressing further comprises an absorption layer for absorbing wound exudate. [Appended claim 57] The method according to any one of appended claims 44 to 56, wherein the wound dressing further comprises a wound contact layer disposed in contact with the wound under the loaded wound dressing layer. [Appended claim 58] A wound dressing comprising: A porous matrix including a front surface and a back surface facing the wound; A powder charge of an antibacterial release additive loaded in the matrix, and a loaded wound dressing layer, wherein the amount of the powder charge decreases as the distance from at least the front surface facing the wound increases. [Appended claim 59] The wound dressing according to claim 58, wherein the matrix comprises a polymer foam. [Appended claim 60] The wound dressing according to claim 58, wherein the matrix comprises a fiber matrix. [Appended claim 61] The wound dressing according to any one of claims 58 to 60, wherein the matrix comprises a hydrophilic polymer. [Appended claim 62] The wound dressing according to any one of claims 58 to 61, wherein the antibacterial release additive contains silver element, silver salt, silver complex, its caged form, caged form of iodine and combinations thereof. [Appended claim 63] The wound dressing according to any one of claims 58 to 61, wherein the antibacterial release additive is selected from the group consisting of silver sulfadiazine, silver zeolite, silver sulfate, silver carbonate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate, cadexomer iodine, and combinations thereof. [Appended claim 64] The antibacterial release additive is 1.4 mg / cm 2 ~ 4 mg / cm 2 The wound dressing according to any one of appended claims 58 to 63, which is in the amount of [Appended claim 65] The wound dressing according to any one of appended claims 58 to 64, further comprising a wound contact layer under the loaded wound dressing layer. [Appended claim 66] The wound dressing according to any one of appended claims 58 to 65, further comprising a cover layer on the loaded wound dressing layer. [Appended claim 67] The wound dressing according to any one of appended claims 58 to 66, further comprising a fluid connector configured to connect the cover layer to a negative pressure source. [Appended claim 68] The wound dressing according to any one of appended claims 58 to 67, further comprising an absorption layer on the loaded wound dressing layer. [Appended claim 69] The wound dressing according to claim 68, wherein the absorption layer contains superabsorbent particles. [Appended claim 70] The wound dressing according to any one of appended claims 58 to 69, wherein the powder charge further comprises a superabsorbent polymer. [Appended claim 71] The wound dressing according to any one of appended claims 58 to 70, wherein the powder charge of the antibacterial release additive has a particle size of about 1 micron < D90 < 30 microns and D50 < 10 microns. [Appended claim 72] The wound dressing according to any one of appended claims 58 to 71, wherein the powder charge further comprises a flow agent selected from stearates, clays, silica, carbon, graphite, and combinations thereof, and the flow agent has a particle size smaller than that of the antibacterial release additive. [Appended claim 73] The wound dressing according to any one of appended claims 58 to 72, wherein the matrix contains a plurality of cells, and the antibacterial release additive is at least partially embedded in the cells.

Claims

1. A wound dressing comprising a loaded wound dressing layer, wherein the loaded wound dressing layer has a front surface and a back surface facing the wound, and between them, a porous matrix including a network of cells having a cell network surface and a structural matrix framework defining a network of pores or cell openings therein, a powder charge of an antibacterial release additive loaded in the porous matrix, and wherein the amount of the powder charge decreases as the distance from at least the front surface facing the wound increases, the powder charge further includes a lubricant selected from stearates, clays, silica, carbon, graphite, and combinations thereof, the powder charge is present on one or both of the front surface and the back surface facing the wound, and is not present or is present in an incidental or minor amount in the cell network and in the structural matrix framework, a wound dressing.

2. The wound dressing according to claim 1, wherein the porous matrix includes a polymer foam.

3. The wound dressing according to claim 1, wherein the porous matrix includes a fiber matrix.

4. The wound dressing according to any one of claims 1 to 3, wherein the porous matrix includes a hydrophilic polymer.

5. The wound dressing according to any one of claims 1 to 4, wherein the antibacterial release additive includes silver element, silver salts, silver complexes, their caged forms, caged forms of iodine, and combinations thereof.

6. The wound dressing according to any one of claims 1 to 4, wherein the antibacterial release additive is selected from the group consisting of silver sulfadiazine, silver zeolite, silver sulfate, silver carbonate, silver chloride, silver nitrate, silver oxide, silver phosphate, silver citrate, silver acetate, silver lactate, cadexomer iodine, and combinations thereof.

7. The antimicrobial release additive is in an amount of 1.4 mg / cm ２ to 4 mg / cm ２ on the surface facing the wound, and the wound dressing according to any one of claims 1 to 6.

8. The wound dressing according to any one of claims 1 to 7, further including a wound contact layer under the loaded wound dressing layer.

9. The wound dressing according to any one of claims 1 to 8, further including a cover layer on the loaded wound dressing layer.

10. The wound dressing according to claim 9, further including a fluid connector configured to connect the cover layer to a negative pressure source.

11. The wound dressing according to any one of claims 1 to 10, further including an absorption layer on the loaded wound dressing layer.

12. The wound dressing according to claim 11, wherein the absorption layer includes superabsorbent particles.

13. The wound dressing according to any one of claims 1 to 12, wherein the powder charge further comprises a superabsorbent polymer.

14. The wound dressing according to any one of claims 1 to 13, wherein the powder charge of the antibacterial release additive has a particle size of about 1 micron < D90 < about 30 microns to D50 < about 10 microns.

15. The wound dressing according to any one of claims 1 to 14, wherein the fluidizing agent has a particle size smaller than that of the antibacterial release additive.

16. The wound dressing according to any one of claims 1 to 15, wherein the porous matrix includes a plurality of cells, and the antibacterial release additive is at least partially embedded in the cells.

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