Cuttable wound treatment product stabilized under pressure for necrotic ulcers

Abstract

The invention relates to a cuttable wound treatment product comprising a liquid-permeable layer with a nonwoven, a protective layer with a nonwoven and a swelling layer. The swelling layer comprises an aqueous salt solution and superabsorbing fibers. The superabsorbing fibers are present in the form of a textile composite together with at least one type of auxiliary fibers. Optionally, the wound treatment product can have a backing portion at the top side and a silicone-containing non-traumatic wound contact layer at the bottom side. The wound treatment product can be realized without seams and is impressive due to the outstanding pressure stability.

Description

Technical Field

[0001] This invention relates to a textile-based multilayer wound treatment product suitable for treating various wounds, particularly ulcers and especially plantar ulcers. Through its special construction, this wound treatment product is capable of performing physical-autolytic debridement, thereby gently removing necrotic tissue from the wound and thus inducing wound closure. Background Technology

[0002] Wound dressings used for wet wound treatment are basically those known in the prior art.

[0003] For example, a variant is described in WO 2011 / 141454 A1. This involves a wound-lining or dressing-type wound dressing that can be applied to a wound or used for packing deeper wounds. The product consists of an aspirator / sweeper with a surrounding weld seam and a saline solution applied at the manufacturer's end, resulting in a superabsorbent material that swells and transforms into a gel state. In the case of wounds with significant exudation, this gives the aspirator / sweeper a dual function: wound secretions (including components such as bacteria contained therein) are actively absorbed and fixed within the aspirator / sweeper, which releases the saline solution into the wound upon replacement, thus creating or supporting a moist wound environment. This supports wound cleanliness and favorable wound condition regulation, thereby advantageously influencing healing. This is known as interactive moist therapy, which is particularly suitable for poorly healing wounds, clinically apparent infected wounds, or chronic wounds with different origins, preferably such as diabetic gangrene, pressure ulcers, or lower extremity ulcers. However, this type of wound dressing has the following drawbacks: they cannot be (after manufacturing) designed to fit (e.g., cut to) the size of the wound. This is because, during cutting, the external barrier (including the weld seam) breaks and the gel subsequently swells out. Cutting in a dry state and subsequently adding liquid is also impractical, as the superabsorbent particles fall out from the inside after cutting and, in the worst case, remain in the wound. Even without cutting the product, it is possible that under greater pressure the weld seam tears and the gel or particles formed by the superabsorbent polymer (SAP) leak out. Therefore, such products from the prior art are unsuitable for treating plantar ulcers (as often occurs in diabetic patients) or should only be used if the patient avoids preventing plantar ulcers, for example, by lying down or elevating the thigh involved. In other cases, the wound dressing is at risk of bursting once the patient supports their weight on the foot being treated. Lying down or using a cane is a burden for the patient. Prolonged lying down increases the risk of blood clots, and canes are considered too much of a burden, especially for older patients.

[0004] The content shown in WO 2011 / 141454 A1 applies in almost identical manner to the wound dressing in WO 2016 / 156619 A1. This wound dressing is also designed for wet wound treatment and is provided as a flat material consisting of multiple layers joined together only at the edges by welds. In other cases, these layers may, for example, slide relative to each other during body movement, resulting in a flexible arrangement. This wound dressing is also not cut and is not suitable for application to the soles of the feet.

[0005] While the aforementioned products can be used to treat ulcers, such as open wounds on the leg, there are generally several problems: because these products cannot be cut to the size of the wound, they inevitably extend beyond the wound's surface, and because they are applied in a wet form, the healthy skin around the wound swells with prolonged application. In medical terminology, this undesirable effect is called maceration and, in the worst cases, can lead to wound enlargement.

[0006] Therefore, there is a need for wound dressings that are suitable for treating various wounds (especially ulcers, and more specifically, plantar ulcers), can be cut to remove necrotic tissue, and create a moist wound environment to facilitate wound closure, and more specifically, to ensure that the patient's freedom of movement is not restricted during treatment. Additionally, maceration of the wound edges should be avoided. Summary of the Invention

[0007] The above objective is achieved by providing a wound treatment product comprising the following components: a) A liquid-permeable layer of nonwoven fabric laid proximal to the side. b) A protective layer with a non-woven fabric lining on the distal side. c) A swollen layer in the form of a nonwoven fabric containing polymer-containing superabsorbent fibers, laid between the proximal, liquid-permeable layer and the distal, protective layer, wherein the superabsorbent fibers are present in the form of a felt together with at least one other type of fiber. d) An aqueous salt solution stored in the swollen layer, having a pH < 7.0 in its stored state, and capable of being released to the wound during wound treatment. The proximal, liquid-permeable layer, the swelling layer, and the distal, protective layer have identical cuts and adhere to each other without any protrusions, and the wound treatment product is designed to be seamless.

[0008] Alternatively, the wound treatment product may consist of the components mentioned above.

[0009] With the above-described construction, the wound dressing according to the invention can be cut to the size of the wound and, when configured for application to the sole of the foot, allows the patient to remain mobile during treatment. It also prevents the wound dressing from extending beyond the sole of the foot, thus allowing for, for example, wearing shoes. When weight is shifted onto the wound dressing, the wound is more thoroughly cleansed by the saline solution, and upon subsequent removal of the load (to the other leg), most of the solution is reabsorbed by the wound dressing. This results in repeated physical-autolytic debridement, which removes cellular debris, pus, and especially necrotic surfaces. Simultaneously, in the case of wound infection, pathogens are washed out of the wound and absorbed by the wound dressing, which retains the pathogens within the dressing. This, along with the moist wound environment, creates optimal conditions that particularly stimulate healing of chronic wounds and improve the quality of life for the patients involved. Detailed Implementation

[0010] The term "cuttable" means that a product or material can be specifically reduced to a user-defined size using commercially available mechanical tools such as scissors before application, without compromising the functionality of the product or material or causing undesirable (partial or complete) disintegration of the product or material.

[0011] The term "medically acceptable material" in the sense of this invention refers to a non-toxic, lint-free, and durable substance that does not decompose in polar or non-polar substances under normal conditions and is not significantly degraded by the secretions of animal and bacterial cells.

[0012] The term "non-invasive" means that the wound care product is not firmly attached to the wound, i.e., it does not dry or grow into the wound, and the product can be removed painlessly without interfering with the healing process.

[0013] The statement "configured for placement flat on a wound" can be understood as meaning that the wound treatment product is designed to be placed flat on a wound for therapeutic purposes.

[0014] "Ringer's solution" is understood to be an aqueous solution of sodium chloride, potassium chloride, and calcium chloride that is substantially isotonic (osmotic concentration of approximately 308 mOsm / L) (specifically, 8.6 g NaCl, 0.3 g KCl, and 0.33 g CaCl2 per liter of water). Ringer's solution is generally sterilized before use.

[0015] In the context of this invention, "proximal" refers to a position within a wound treatment product such that it is positioned within the product toward the wound during application. This is, for example, in the case of a wound contact layer.

[0016] In the context of this invention, "distal" means a material or substance occupying a position within a wound treatment product such that it is positioned away from the wound arrangement within the product during application to wound treatment, for example, in the case of a backing (the final support layer).

[0017] "SAF" is an abbreviation for superabsorbent fiber. These fibers can absorb polar liquids several times their own weight and can be processed with other fibers into stable fiber complexes.

[0018] "Additional fibers" refers to fibers that are different from superabsorbent fibers (SAF) and are therefore not SAFs themselves.

[0019] "Wet vapor transmission rate" or "MVTR" refers to the rate at which water vapor can pass through a material, expressed in g / m³. 2 The MVTR is the measurement value of the 24h meter. It can be determined with the aid of standard DIN EN 13726-2 (June 2002).

[0020] The wound treatment product of this invention consists of at least three layers: a proximal, liquid-permeable layer, a swelling layer, and a distal, protective layer. All three layers have identical cuts, allowing them to adhere seamlessly to each other without protrusions. However, minor deviations (tolerances) due to manufacturing processes are possible without limiting functionality. Here, one or two layers may extend beyond another layer or multiple layers by up to 5 mm.

[0021] A proximal, liquid-permeable layer can be used as a wound contact layer. Alternatively, the wound treatment product can be equipped with an additional silicone-containing layer, which then functions as a wound contact layer and provides outstanding non-invasive properties. The corresponding working principle will be explained in detail elsewhere.

[0022] The distal protective layer covers the swollen layer in the distal direction, protecting it from external influences and making the wound treatment product easier to handle by improving tactile properties. The effectiveness of the protective layer can be further enhanced by additionally applying a backing layer, which will be explained in detail elsewhere.

[0023] The pressure resistance is imparted by the product's construction, in which the composition of the swelling layer (including a felt formed from SAF and additional fibers) and the resulting elimination of weld seams play a decisive role. "Seamless" specifically means that the product has no weld seams. The desired pressure resistance value can be achieved in this way. Accordingly, the wound treatment product responds to mechanical pressure solely through elastic deformation, and thus reversible deformation. It can therefore be preferably proposed that the wound treatment product has a pressure resistance of at least 8 kg / 100 cm. 2 Preferred weight: 20 kg / 100 cm2 Preferably at least 50 kg / 100 cm 2 And the optimal weight is 120 kg / 100 cm. 2 Pressure tolerance. Pressure tolerance should be understood in terms of the force distributed over the entire (distal or proximal) area of ​​the wound treatment product (whole-surface pressure tolerance).

[0024] The following methods can be used to test stress tolerance: 1) Provide wound care products that are treated with aqueous saline solution, and the disinfection has been carried out within the last 14 days. 2) Place the (unpackaged) product in a commercially available clear ZIP bag. 3) Generate the gravity to be tested within one second. 4) Hold this gravity for one second. 5) Release the gravitational force within two seconds. 6) Repeat steps 3 to 5, applying the gravity a total of ten times. 7) Remove the product from the bag. 8) Visually inspect the product and the inside of the bag for any separated fibers or leaking gel. When no separated fibers or leaked gel are visible on the product itself or inside the bag, the test is considered passed for the corresponding gravity.

[0025] The wound treatment product is preferably designed so that, due to its elastic properties and pressure resistance, it can be coiled or folded 90°, more preferably 180°, along the actual or (in the case of an asymmetrical construction) imaginary centerline, more precisely without plastic deformation.

[0026] In addition to the aforementioned nonwoven fabric, the proximal, liquid-permeable layer and the protective layer may also include other components, such as other fiber arrangements, provided that these fiber arrangements do not disintegrate after the cutting process. The liquid-permeable layer and the protective layer are preferably composed entirely of nonwoven fabric, because nonwoven fabrics have particularly high tolerance to fiber separation, more specifically after the material has been cut.

[0027] The swelling layer comprises superabsorbent fibers (SAF), particularly superabsorbent fibers comprising a superabsorbent polymer. The superabsorbent polymer preferably comprises an acrylate-containing polymer or an acrylate copolymer. The SAF can have a fiber diameter of, for example, 50 to 500 µm. A fiber diameter of 100 to 200 µm is preferred because an ideal water-to-fiber ratio can be achieved at this diameter. This allows a large amount (e.g., 15 ml) of aqueous saline solution to be released from the swelling layer into the wound, but it can also be reabsorbed. This mechanism is based, on the one hand, on a chemical-physical process such as diffusion, in which the clean saline solution migrates towards the wound while the washed wound exudate migrates towards the swelling layer. On the other hand, the saline solution is partially extruded under mechanical pressure and reabsorbed by the swelling layer upon release of pressure. The possibilities for providing and adapting SAFs are explained in detail elsewhere.

[0028] The wound treatment product is preferably planar, meaning it has a flat distal top surface and an equally flat proximal bottom surface, making it particularly suitable for covering wounds and terminating flush with the wound edges. "Flat" means that the corresponding layers have no noticeable bumps or depressions. The already mentioned protective layer can be used as the top surface. Similarly, the already mentioned proximal liquid-permeable layer can be used as the bottom surface. This allows the product to cover the wound well. The flat bottom surface contributes to its non-invasive properties and reduces wound irritation.

[0029] The wound treatment product is also preferably (in top view) circular or oval. Compared to a rectangular shape, its advantage is that this product, in its uncut state, already approximates the shape of most chronic wounds, which (unlike, for example, cuts) generally have a nearly circular appearance. Furthermore, it has been shown that circular or oval shapes provide better and more durable fixation to the sole of the foot and cause less interference with the substrate compared to other shapes, such as rectangular designs with rounded corners (as often used in the case of abrasions). In addition, rectangular designs have the disadvantage that under sustained mechanical stress (e.g., while walking), they rapidly begin to peel off from the skin in the corner areas. At this point, the corners tend to curl up, resulting in undesirable bulges and potentially causing tenderness in the sole area.

[0030] To lay flat on or cover the wound, the protective layer is preferably overlaid in the distal direction by means of an additional backing layer that counteracts the evaporation of the saline solution, allowing for continuous, non-replacement wet wound treatment over several days. This backing layer or liner also provides supportive properties that simplify the wrinkle-free application or adhesion of the wound treatment product. Advantageously, SAF exhibits outstanding water-retaining properties within this swelling layer. The felt material of the swelling layer further absorbs and retains substances and harmful organisms (such as bacteria) washed from the wound until it is discarded at the next bandage change.

[0031] The wound treatment product according to the invention comprises a swollen layer in the form of a nonwoven fabric containing polymer-containing superabsorbent fibers, wherein these superabsorbent fibers are present as a fiber complex in a felt with at least one other type of fiber (additional fiber). The purpose of these additional fibers is to impart sufficient tear and tensile strength and shape stability to the swollen layer in a wet state. Since the SAF is present as a felt together with the additional fibers, they form a stable fiber complex.

[0032] Regarding the swelling layer, the additional fiber (the extra fiber) can be of synthetic, natural, or semi-synthetic origin, with SAF explicitly excluded. Examples of suitable synthetic-origin fibers are polyolefin-based fibers, such as polyesters and polyamides. Polyethylene terephthalate is particularly preferred within the group of polyesters. Examples of suitable natural-origin fibers are, for example, cotton and linen. Examples of semi-synthetic-origin fibers are dissolving fibers. Natural and semi-synthetic fibers generally form the group of cellulose-containing fibers, provided that it contains a cellulose portion.

[0033] The additional fiber exists together with the SAF in the form of a felt, preferably a needle-punched felt. That is, the two types of fibers are felted together. The felt can be made into a wet felt or a dry felt. Making it into a dry felt is preferred because this avoids the SAF from drying out again. The dry felt can be provided as a needle-punched felt, an adhesive felt, or a thermosetting melt felt. In the case of a needle-punched felt, the additional fiber and the SAF are mechanically needle-punched together to form a felt. Here, the additional fiber (the additional fiber) is needle-punched with a polymer-containing superabsorbent fiber, so that it exists in the form of a needle-punched felt. In the case of an adhesive felt, the two fibers are joined together by incorporating an adhesive (mainly through chemical interaction). The adhesive used should not be water-soluble after curing, as otherwise it may disintegrate due to the action of an aqueous salt solution. In the case of a melt felt, the additional fiber is selected from the range of melt fibers and is joined together with the SAF (which has inherent melt fiber properties) by using heat. The fibers of the swollen layer are preferably present as a needle-punched felt or present in the needle-punched felt. The swollen layer in the form of needle-punched felt offers the following advantages: it is compatible with all sterilization methods because it exhibits outstanding resistance to heat, pressure, water vapor, radiation, and ethylene oxide. Furthermore, the needle-punched felt form allows for greater freedom in fiber selection and provides a very long shelf life even under long-term storage conditions.

[0034] The swollen layer constructed in this way can be cut without problems, without causing the SAF to detach from the additional fibers, and without causing superabsorbent particles, as commonly used in absorbent wound dressings, to fall out of the swollen layer from the cut area. Furthermore, durable adhesion can be achieved at other layers of the wound treatment product. Thus, for example, the swollen layer can be bonded to other materials on its distal and proximal sides. Examples of how such laminates can be obtained will be illustrated in the embodiments.

[0035] The wound treatment product according to the invention is particularly suitable for use in wet wound therapy. Here, "suitable for use in wet wound therapy" or "for use in wet wound therapy" means that the product can be used without any other preparation or modification, such that wet wound therapy can be initiated directly by applying the product. Furthermore, the wound treatment product can be stored in a moist state between preparation and use without affecting its structural integrity.

[0036] The salt solution contained within the swollen layer washes the wound, thereby dissolving surface components (such as fibrin), aiding in the autocatalytic decomposition of necrotic tissue, and removing microorganisms. Excess metalloproteinase matrix is ​​washed out of the wound, restarting the stalled healing process. A moist environment generally also accelerates wound closure.

[0037] When applied to the sole of the foot, the product stimulates venous blood flow during movement, which is particularly significant in cases of chronic wounds attributed to venous stasis (such as lower extremity ulcers, also known as "open wounds of the leg"). Because the product's shape can be tailored to fit the wound, it avoids extending beyond the wound's boundaries and thus prevents maceration of the surrounding skin, even in cases of moist wound care. Furthermore, the product can be worn significantly more comfortably under compression bandages or stockings, as in cases of pressure sores, to relieve pathological venous stasis.

[0038] The wound treatment products according to the invention are particularly suitable for the treatment of slow-healing or non-healing and chronic wounds, especially wet wound treatment. These include, in particular, the following wound types: diabetic foot lesions, lower extremity venous ulcers, lower extremity arterial ulcers, lower extremity arteriovenous ulcers, and pressure sores. These wounds are unique in that they often have a surface (e.g., a fibrinous surface) and necrotic tissue. Furthermore, the hindered healing process is accompanied by an imbalance of messenger substances, enzymes (e.g., matrix metalloproteinases), and molecular inhibitors required in the wound. In wet wound treatment, the previously dominant chemical imbalance is overcome by cleaning the wound, and the environment necessary for wound healing can be established. In this way, previously hindered healing is put back on track. As already mentioned, the wound treatment products according to the invention can, in the most general case, be combined with pressure therapy to overcome venous blockage, which is a causal problem triggering ulcers.

[0039] According to one embodiment of the invention, the wound treatment product includes a backing layer (support layer) laid distally relative to the protective layer. This backing layer can be designed in the form of a foil or a film. The backing layer is preferably present as a film. It is also preferred that the backing layer comprises polyurethane (PU) or, in particular, a composition thereof. PU offers the advantage that it (depending on the processing) is less noisy or even noiseless; conversely, other synthetic materials often produce a harder and more rattling impression and are therefore perceived as uncomfortable by some patients.

[0040] Alternatively, the backing layer can be composed of polyolefins such as polyethylene (PE) or polyvinyl chloride (PVC) or polyester. The evaporation from the swollen layer can be significantly reduced by using a backing layer in the form of a film or foil. This allows for a longer residence time of the product on the wound without limiting its functionality in the sense of wet wound care or in the suction-washing mechanism characteristic of the product.

[0041] The backing layer can be transparent. This allows for visual control to assess whether the swelling layer has absorbed the maximum possible amount of wound exudate and thus established a stable fluid balance between the wound and the wound treatment product. If so, a decision to replace the bandage can be made. The used wound treatment product can then be disposed of along with the absorbed wound fluid, irritants, dissolved surfaces, and other components bonded thereto. After applying a new wound treatment product according to the invention, the wound is continued to be cleansed with fresh saline solution. Furthermore, the transparent backing layer allows for estimation of whether bacterial infection of the wound has occurred, as this is often accompanied by a change in the color of the exudate.

[0042] According to a preferred embodiment, the backing layer should substantially have an extension of the protective layer. According to another embodiment of the wound treatment product, the backing layer extends beyond the protective layer and thus forms a surrounding adhesive edge. This is particularly effective in preventing clothing layers or therapeutic textiles (e.g., compression stockings or bandages) supported on the wound area from becoming wetted by saline solution or wound exudate, and allows the portion of the aqueous saline solution released into the wound to be reabsorbed back into the swelling layer particularly efficiently.

[0043] Particularly suitable devices for securing the wound treatment product according to the invention at the wound site are secondary bandages, such as adhesive foil, gauze, bandages, and plaster strips. Adhesive foil is preferred among these devices because, like the wound treatment product itself, it can be cut without impairing or losing its function. Additionally, adhesive foil reduces evaporation and does not hinder patient walking, even when applied to the sole of the foot. Furthermore, the adhesive foil can be designed to be watertight, thereby protecting the wound treatment product from unwanted external forces (e.g., during showering).

[0044] The backing or backing layer is particularly preferably elastic and / or printable and / or impermeable to water and water vapor. In this sense, materials that are impermeable to water and water vapor with a wet vapor transmission rate (MVTR) of less than 1000 g / m³ should be understood as such. 2 / 24h, preferably below 800 g / m 2 / 24h, still better below 600 g / m 2 / 24h and optimally below 100 g / m 2 / 24h. It can also be stated that the backing is watertight against water columns of 800 mm, preferably 1300 mm, and most preferably 2000 mm. These values ​​can be achieved, for example, by the backing or backing layer comprising or consisting of PU or PET. Where applicable, thicker foil provides a lower MVTR value. Here, the backing layer can, for example, have a thickness of 0.2 mm to 1 mm or 0.3 mm to 0.8 mm (corresponding to height in the side view of the finished product). The actual adhesive coating is still not considered in the measurements here. Generally, a layer thickness of 0.2 mm is sufficient to achieve below 1000 g / m³. 2 / 24h MVTR. The given MVTR values ​​relate to aqueous salt solutions, preferably isotonic salt solutions, and particularly preferably isotonic Ringer's solutions.

[0045] The backing layer can be secured to the support layer by means of an adhesive. The adhesive can be applied across the entire surface, but it is preferred to apply it in a patterned manner because the untreated gaps allow for better gas exchange. Acrylic adhesives have been shown to result in particularly stable and durable fastenings, making them the preferred adhesive.

[0046] The nonwoven fabric with a proximal, liquid-permeable layer and / or protective layer can contain thermosetting fibers. This improves bond strength and simultaneously produces a lighter nonwoven fabric, resulting in material savings. Meanwhile, water permeability remains unchanged. Thermosetting nonwoven fabrics can contain thermoplastic fibers. Examples include polypropylene (PP), polyvinyl chloride (PVC), polyethylene (PE), polyester (PET), polyacrylic acid (PC), polyacrylonitrile (PAN), polyamide (PA), polyurethane (PU), viscose fiber (CV), and mixtures of two or more of these types of fibers. Additionally, thermoplastic additives can be included. An example of a thermoplastic additive is PET.

[0047] To prepare suitable thermosetting nonwoven fabrics, fibers laid out in loose nonwoven fabric can be heated to their melting point, thereby connecting them together.

[0048] For use, calendering curing (also known as thermal bonding) or hot air curing (also known as thermal fusion) can be performed, with calendering curing proving particularly useful in the case of PP fibers.

[0049] When using fibers that are not suitable for heat curing in their pure form, adhesive fibers can be incorporated to allow heat curing to still be achieved in this manner. Thus, in addition to thermoplastic fibers and thermoplastic additives, heat-cured nonwovens can also contain other types of fibers, such as cotton or viscose fibers. These fibers are preferably naturally derived or partially synthetic fibers such as viscose fibers.

[0050] Heat transfer for thermosetting can be achieved through conduction, convection, or radiation. Calendering and hot air methods are particularly suitable. This type of curing can transform loose fibrous nonwoven fabric into a strong and durable nonwoven fabric. This significantly reduces the risk of fibers detaching and entering wounds.

[0051] The SAF in the swelling layer may comprise a polymer containing acrylates or be composed of polymers. This polymer may be polyacrylamide or a polyacrylamide derivative, or an acrylamide copolymer. According to a preferred embodiment of the invention, the SAF in the swelling layer of the wound treatment product comprises a laterally crosslinkable polymer. Examples of laterally crosslinkable polymers that can be used to obtain SAF or can form components of SAF are acrylate-containing polymers or acrylate copolymers.

[0052] The SAF in the swelling layer of this wound treatment product preferably comprises a laterally crosslinked polymer. Lateral crosslinking preferably involves the formation of ester compounds. The laterally crosslinked polymer can be laterally crosslinked or is capable of being laterally crosslinked through these ester bonds. The degree of lateral crosslinking can set the bendability or resistance (bending resistance torque) of the SAF in the presence of an aqueous salt solution. A higher degree of lateral crosslinking results in a softer gel-like texture of the SAF, allowing it to exist as a hydrogel in the presence of water or other aqueous liquids such as wound exudate. Simultaneously, the overall load-bearing capacity of the swelling layer, and therefore the wound treatment product, increases with the degree of lateral crosslinking.

[0053] Lateral crosslinking can be achieved through acrylate bonding. Crosslinking can be carried out via free radical or cationic polymerization mechanisms, or other esterification or transesterification mechanisms (e.g., Michael addition). Free radical polymerization is preferred. Polyacrylamide can be laterally crosslinked by introducing it into an acidic environment. Furthermore, depending on the reaction rate, the pH value can be less than 6.0, less than 5.0, or less than 4.0. For example, the pH value can be in the range of 3.0 to 6.0, or 1.0 to 5.0, or 0.0 to 4.0.

[0054] In this context, SAF can contain 5% to 50%, preferably 10% to 40%, of a transversely crosslinked polymer. In the case of an acrylic polymer, the degree of transverse crosslinking can be determined by the amount of acrylic groups transversely crosslinked via ester bonds within the polymer. Therefore, at a degree of 50% transverse crosslinking, half of the acrylic groups are transversely crosslinked.

[0055] Additionally, SAF may contain copolymers, which may be acrylic copolymers.

[0056] A possible example is poly(acrylic acid-co-acrylamide) / polyvinyl alcohol. It can be directly spun into SAF.

[0057] The transverse cross-linking of SAF does not preclude it from being needle-punched into needle-punched felt with at least one other type of fiber (not an additional fiber to SAF). Transverse cross-linking can be performed before or after needle-punching, but it is recommended to perform transverse cross-linking before needle-punching because this allows for more precise setting of the degree of cross-linking. Thermosetting can follow needle-punching, where these three measures (transverse cross-linking, needle-punching, and thermosetting) complement each other and produce a swollen layer that, after being cut by the end consumer or caregiver, exhibits outstanding moisture retention, moisture release, and excellent mechanical strength.

[0058] The ratio of SAF to additional fibers in the swollen layer can be expressed, for example, as 20% to 80% by weight of SAF and 80% to 20% by weight of additional fibers. The proportion of SAF in the swollen layer is preferably 20% to 60% by weight, particularly preferably 20% to 40% by weight, with the remainder being additional fibers. A possible embodiment includes 25% by weight of SAF and 75% by weight of polyolefin-based fibers in the swollen layer.

[0059] According to the invention, the liquid-permeable layer, the swelling layer, and the protective layer can be connected to each other over their entire surfaces (i.e., over the entire area of ​​the respective top or bottom surfaces). These surfaces can be adhesively connected to each other, wherein the adhesive connection can be direct (directly adjacent) or indirect (e.g., by inserting an additional intermediate layer, such as a perforated double-sided adhesive foil or a porous fused foil (thermoplastic) design). These layers can be bonded together or connected in an adhesive manner, for example, by an adhesive or bonding bond. The bonding bond or adhesive layer can exist as a cohesive layer in the finished product, that is, in which the particles (atoms, molecules, etc.) of the adhesive attract each other. Hot melt adhesives or hot melt bonding are preferred. Examples of possible hot melt adhesives are copolymers and polyolefin-based hot melt adhesives such as polyesters or polyester derivatives such as copolyesters. Such hot melt adhesives are particularly suitable for permanently bonding nonwoven layers, especially those containing synthetic fibers. Furthermore, hot melt adhesives are generally technically compatible with subsequent heat sterilization. The melting point can also be lower than the subsequent sterilization temperature because the product is already in secondary packaging during sterilization, which imparts additional stability to the article. Thus, the melting point of the hot melt adhesive or hot melt adhesive bond can be, for example, from 45°C to 120°C, preferably from 45°C to 70°C. Where necessary, this can be achieved, for example, by using copolyesters at melting points up to 140°C, and even partially exceeding this maximum melting point. It is recommended that the wound treatment product be sterilized in a moist state (i.e., with the contained aqueous saline solution), because a lower sterilization temperature (e.g., 120°C) is sufficient to achieve a adequate duration of action.

[0060] The hot melt adhesive described above can be fed into the melting process of different initial materials. Therefore, it is possible to provide the hot melt adhesive in granular form, as a mesh, or as a foil. Providing it in granular form or as a mesh is preferred because it does not limit the portability of the resulting product. Additionally, granules offer the advantage of flowability. Foils and meshes are particularly suitable when different hot melt adhesives should be combined with each other. Here, the hot melt adhesive combination can produce adhesive bonds with particularly high load-bearing capacity, where one of the adhesives used in the preparation process fixes the corresponding layers, and another adhesive (with a higher melting point) reacts during the sterilization process and further strengthens the initial bond, without expending additional heat energy during this process.

[0061] These layers of the wound treatment product, particularly the liquid-permeable layer, the swelling layer, and the protective layer, can exist as a laminate, to which other layers, such as an adhesive carrier (proximal) or a backing (distal), can also be bonded and become part of the laminate. For this purpose, these layers can be bonded together using heat and / or by means of an adhesive. A laminate is also produced when using an unheated adhesive (in this case, a cold laminate). It is suggested that the aforementioned hot melt adhesive be applied between these layers to make the resulting laminate more durable. The required temperature depends on the material being treated and can be, for example, in the range of 45–160°C. Normally, an action time of 2 seconds to 10 minutes is sufficient. The optimal action time varies depending on the selected temperature, but in most cases falls within the range of 2 to 30 seconds.

[0062] The adhesive bonding of the layers together in this wound treatment product has the advantage of forming a planar connection that holds the layers together even after possible cutting of the product. This planar connection is preferably a full-surface adhesive bond, particularly preferably a full-surface adhesive bond, and ideally a full-surface hot melt adhesive bond. Conversely, methods that merely bond the layers together along their edges (e.g., classic welding) do not produce a product that can be cut.

[0063] Another possibility for connecting these layers is to anchor the fibers of one layer into the adjacent layer. This can be achieved, for example, by weaving or felting.

[0064] This wound treatment product can be cut into two or more pieces. All pieces obtained in this way can be used in wound treatment. The cut pieces allow the aqueous saline solution stored in the swollen layer to be released to the wound, simultaneously washing and cleaning it.

[0065] Another aspect of the invention relates to a cuttable planar wound treatment product, wherein the liquid-permeable layer, the swelling layer, and the protective layer are planarly joined together via a fusion bond, and wherein the fusion bond comprises or is composed of molten polyolefin or molten copolymer. Such a laminate can be advantageously cut without grinding off the cut edges.

[0066] A particular advantage of the cutable planar wound treatment product according to the invention is that the cleansing effect produced by the product is enhanced or strengthened by repeated reversible (non-plastic) deformation or by repeated pressure compression. In practice, this can be achieved, for example, by applying the wound treatment product to the sole of the foot and then repeatedly applying and unapplying pressure as the patient or end-user walks. In this way, upon stepping, a portion of the aqueous saline solution, which is compressed by body weight and is not firmly bonded to the SAF, is squeezed out from the wound treatment product. Once the patient lifts their foot and the product unfolds again, the released portion of the saline solution (along with dissolved substances, irritants, etc.) is reabsorbed. This process is repeated during walking, achieving a particularly high-intensity flushing of the wound.

[0067] Another possibility, for example, in treating open wounds on the leg is to apply the wound care product and then wrap it with a compression bandage. The compression bandage here acts as a docking support for what is known as a muscle-venous pump. The wound care product is compressed between the body surface and the compression bandage during muscle contraction. Upon subsequent muscle relaxation, the wound care product can be unwound again. This spontaneously generates muscle tension during walking. If the patient is bedridden, alternatively, appropriate exercises can be performed while lying down, for example, under the guidance of a physical therapist. Even in this mentioned case, a beneficial enhanced cleansing effect has been observed.

[0068] In this sense (enhanced cleaning effect), the description of "repeated reversible deformation" or "repeated reversible pressure compression" means that when the wound treatment product is deformed or compressed at least three times and simultaneously returns substantially to its initial form each time without additional support, the wound treatment product can clean the wound in an enhanced manner. Enhanced cleaning should be understood as the release of a larger volume of aqueous saline solution compared to purely passive mass exchange along a concentration gradient (without deformation or compression) (e.g., to the wound or measuring device). The wound treatment product can, for example, be saturated with aqueous saline solution to 80% of its maximum absorbent capacity in its initial state.

[0069] In the context of this invention, when the product is attached to the sole of the foot, more specifically during walking, the wound treatment product is able to generate a pumping effect that drives the muscles during wound treatment so as to cleanse the wound to be treated with an aqueous saline solution contained in the swelling layer.

[0070] This enhanced cleaning method allows for very gentle cleaning of necrotic areas and fibrin surfaces, generally avoiding the need for invasive surgical cleaning using scalpels, sharp spatulas, etc., which are more burdensome for patients.

[0071] Enhanced cleaning is preferably accompanied by enhanced suction / cleaning, which also results in enhanced absorption of material drained from the wound. For example, microorganisms washed from the wound are retained in the swollen layer and removed during the next bandage change.

[0072] Furthermore, it can be proposed that after the wound treatment product according to the invention is cut, the structural integrity of the remaining area provided for the wound treatment remains unchanged, preventing the release of fibrous or granular components of the cut wound treatment product, especially superabsorbent fibers, through the felt structure of the swollen layer. Such wound treatment products are therefore lint-free, more precisely, precisely after cutting and before application.

[0073] In the wound treatment product according to the invention, a pH value of less than 7.0 may be imparted to the aqueous salt solution by acid groups contained in the superabsorbent fiber, preferably by acrylic acid. This acid group may be contained in the SAF or be part of a polymer constituting the SAF. The polymer may be polyacrylic acid. Advantageously, other components for acidification can be omitted, and a slightly acidic pH value suitable for the healing of most wounds can be set. The pH value of the aqueous salt solution imparted by the acid groups is preferably in the range of 4.5 to 6.9. A pH value particularly preferably in the range of 5.0 to 6.5.

[0074] It is also preferably proposed that the liquid-permeable layer, the swelling layer, and the protective layer have substantially identical lateral dimensional increases upon absorbing the liquid. Substantially identical lateral dimensional increases mean that when these layers absorb the liquid, their planar expansion increases in the same manner, wherein a small area difference of up to 5%, preferably up to 3%, may exist between adjacent layers (after expansion) and is taken into account. The expansion can be measured according to standard AATCC TM135. This similarly applies to the reduction in layer area due to possible shrinkage after liquid release.

[0075] The advantage of having essentially the same area change when these three layers come into contact with liquid is that the wound treatment product will not deform (e.g., bend or bulge) due to liquid absorption and its planar shape will remain unchanged.

[0076] In this context, the liquid-permeable layer, the swelling layer, and the protective layer may also have the same or substantially the same coefficient of lateral thermal expansion, which involves area expansion. A tolerance of up to 5%, preferably up to 3%, is included between the respective adjacent layers. Identical or substantially identical coefficients of lateral thermal expansion provide an advantage for the heat sterilization of the wound treatment product. In other cases, undesirable deformation of the product may occur during sterilization, and sterilization must be performed by other (generally more costly or expensive) methods, such as irradiation or ethylene oxide aeration.

[0077] Identical or substantially identical expansion or thermal expansion can be achieved by using multiple layers of materials that exhibit the same or very similar expansion behavior. Thus, synthetic fibers exhibit very similar expansion and contraction behaviors to each other and compared to cotton.

[0078] According to the present invention, the swelling layer of the wound treatment product includes, in addition to SAF, at least one other type of fiber or at least one additional fiber. Advantageously, cellulose-containing fibers, such as dissolving fibers, polyolefin-based fibers, polyester-containing fibers, preferably polyethylene terephthalate and / or polyamide-containing fibers are involved.

[0079] Soluble fibers have the advantage of outstanding moisture storage capacity, which still exceeds the already high capacity of cotton. Thus, the soluble fibers assist the SAF in a synergistic manner, giving the swollen layer the necessary structural load-bearing capacity and fixing the SAF in its position within the swollen layer.

[0080] Additionally, in wound treatment products according to the invention, it is possible that the nonwoven fabric of the liquid-permeable layer and / or the protective layer comprises viscose fibers and polyester or is composed of these polymers. Here, the polyester proportion in the nonwoven fabric can be, for example, 30 to 50% by mass. By incorporating hydrophobic polyester, a hygroscopic gradient is created from the liquid-permeable layer and the protective layer, which guides the liquid through the liquid-permeable layer and the protective layer in the direction of the swelling layer. Simultaneously, the aqueous salt solution can pass through the liquid-permeable layer from the swelling layer and subsequently reach the wound without being retained in the liquid-permeable layer.

[0081] Alternatively, the liquid-permeable layer and the protective layer may be composed of identical materials or identical mixtures of materials and / or have the same weight per unit area. This could involve the materials or mixtures of materials detailed in the previous paragraph. Using identical materials for both layers simplifies and speeds up the production process, as both layers can be handled by the same type of machine.

[0082] Generally, it is possible that the nonwoven fabric of the liquid-permeable layer and / or the protective layer has a dry density of 15 to 50 g / m². 2 For example, 18 to 45 g / m 2 The weight per unit area. The weight per unit area can be determined using the standard DIN EN12127. It has been shown that layers thus created combine excellent structural load-bearing capacity with high permeability to liquids. These layers retain load-bearing capacity even after possible cutting, without hindering the desired suction / cleaning effect of the wound treatment product.

[0083] Depending on the application area, it may be advantageous for the nonwoven fabric of the liquid-permeable layer to be provided with or coated with silicone or a silicone-containing material on its proximal side. In this sense, the liquid-permeable layer of the wound treatment product according to the invention is at least partially coated with silicone or a silicone-containing material on its proximal side. These substances can be applied to the nonwoven fabric (proximal side) of the liquid-permeable layer. The silicone-containing material can be, for example, a silicone-based adhesive or silicone gel, which does not harden after application and thus maintains its adhesive properties.

[0084] In this sense, the present invention includes wound treatment products having an additional silicone-containing wound contact layer applied directly or as a coated foil to the outside of the liquid-permeable layer (i.e., in the proximal direction).

[0085] It is not recommended to equip finished wound care products with a top-coverage or coating of a liquid-permeable layer, as this may hinder fluid exchange due to the hydrophobic properties of silicone. Instead, it can be applied in a patterned manner, such as in dots, strips, or bars, where these strips can be arranged parallel to each other. Alternatively, it can be applied over the entire surface, and the silicone or silicone-containing material can then be perforated. This perforated, full-surface coating offers advantages over patterned application: regardless of the subsequent cut type, the edge areas of the liquid-permeable layer are always coated, and thus the entire edge has the same height.

[0086] Alternatively, silicone or silicone-containing materials can be applied to the liquid-permeable layer via a foil or film. The foil or film may contain or be composed of PU. It can be coated distally with an adhesive such as an acrylic adhesive. In the context of this invention, the adhesive-coated foil or film is also referred to as an adhesive carrier. The adhesive applied distally is not necessarily skin-compatible. The opposite (proximal) side of the foil or film is coated with the aforementioned silicone or silicone-containing material. Using a film or foil offers the advantages of being preferably kept as a large-scale product (e.g., roll material) and being rapidly and automatically applied to the proximal side of the liquid-permeable layer when needed during the preparation process. The film or foil forms a stable bond with the liquid-permeable layer. When the film or foil is coated all over the proximal or distal side, it is recommended that the adhesive carrier be equipped with continuous perforations before application to the liquid-permeable layer. “Continuous” means that these perforations penetrate the film or foil and both coatings and allow subsequent material exchange through the liquid-permeable layer.

[0087] In addition, the adhesive carrier designed in this way can be applied to the liquid-permeable layer in a whole-surface or patterned manner (e.g., in the shape of strips or dots).

[0088] In this sense, the present invention includes a wound treatment product comprising a silicone-containing wound contact layer that only partially covers the liquid-permeable layer and wherein the silicone-containing wound contact layer is preferably perforated.

[0089] If silicone or silicone-containing materials or the foil are to be perforated, care must be taken to ensure that these perforations are of sufficient size. Thus, the perforations can be 0.05 mm. 2 up to 7.00 mm 2 The area of ​​the perforation is preferred, with a larger perforation area being ideal. Therefore, it can be proposed that the average area of ​​each perforation is 0.8 mm. 2 up to 7.00 mm 2 Or 0.8 mm 2 Up to 6.00 mm 2 .

[0090] These perforations can have different shapes or contours, with round or oval perforations offering the following advantages: they exhibit good load-bearing capacity when the wound treatment product is stretched or bent without tearing. At the same time, the absence of edges or corners provides a comfortable feel against the skin and reduces the risk of irritation to the wound area.

[0091] The open (uncoated) area of ​​the liquid-permeable layer is advantageously in the range of 10% to 25% or 12% to 23% of its total area. The open area can be achieved by the perforations already mentioned, but it can also be achieved by applying the coating in a patterned manner.

[0092] It is recommended to apply the coating as thinly as possible, as this saves material, and more precisely, without compromising quality. Use 100 g / m². 2 Up to 200 g / m 2 120 g / m 2 Up to 175 g / m 2 And a preferred 135 g / m 2 Up to 160g / m 2 The coating amount achieved good results. These values ​​apply to coatings on nonwoven materials as well as foils, and more precisely, to the point before potential perforation. In the case of patterned application, the range given for the coating amount can be correspondingly lower, for example, reduced by 25%.

[0093] In cases where the nonwoven fabric or foil can be coated with silicone or silicone-containing materials, such as silicone adhesives or silicone gels are involved, these adhesives or gels offer the advantage that they can secure the wound treatment product to the wound or wound area non-invasively. That is, the adhesive or gel can be removed painlessly and without damaging newly formed tissue.

[0094] Wound care products according to the invention can have different shapes and sizes. For treating (external) wounds, a flat shape on both sides (i.e., proximal and distal) is recommended. For treating plantar ulcers, it is also advantageous for the wound care product to have a lower height. Such wound care hardly or not at all interferes with the patient's daily activities, as the patient can wear the product under socks and inside shoes and even walk with the product. Such lower heights are from 1.5 mm to 6 mm. Embodiments of the wound care product having an adhesive carrier (proximal) and a backing (distal) also fall within this range. If the wound care product has only a minimal structure consisting of a protective layer, a swelling layer, a liquid-permeable layer, and an optional adhesive layer, the height is still more advantageously from 1.7 mm to 3 mm, preferably from 1.7 mm to 2.5 mm, and particularly preferably from 1.8 mm to 2.2 mm. The given height range values ​​relate to the dry complex (i.e., without aqueous saline solution) formed by the liquid-permeable layer, the swelling layer, and the protective layer as described in this application, and also without optional release liner or other packaging materials. The height of a product treated with an aqueous salt solution (depending on the volume loaded) can typically be increased by about 10% compared to a dry product. Therefore, the wound treatment product in a wet state has a height of, for example, 1.7 mm to 6.6 mm, more preferably 1.9 mm to 3.3 mm, still more preferably 1.9 mm to 2.8 mm, and most preferably 2 mm to 2.4 mm.

[0095] Other possible forms include cushion-like and columnar shapes. Cushion-like variants are responsible for providing particularly good cushioning. This is especially comfortable for patients, for example, when the wound is located at the ankle. Columnar variants are particularly advantageous in the case of tunnel-like wounds and holes, where any protruding ends (extending from the wound) can be simply cut off. This prevents premature closure of the surface wound and the formation of abscesses and subsequent oozing beneath it.

[0096] Therefore, in terms of shape, the wound treatment product can be circular, rectangular, square, oval, or rhomboid in a top view. The area can be, for example, 50 cm². 2 Up to 500 cm 2 The larger area offers the following advantage: it can be cut to the appropriate wound size.

[0097] The swelling layer of the wound treatment product preferably contains the aqueous saline solution in an amount that does not deplete its absorbency. That is, the swelling layer is preferably unsaturated or uncongested. In this way, the swelling layer, or the wound treatment product, can absorb other fluids, such as wound exudate or blood. It is possible that the swelling layer, or alternatively the entire wound treatment product, is saturated with up to 50%, 60%, 70%, 80%, 90%, or 95% of the aqueous saline solution.

[0098] Possibly, the swollen layer is matched in its composition, density, and / or thickness (height elongation) to absorb 100 cm³ of Ringer's solution from a flat container with a filling height of 2 mm and a total Ringer's solution volume of at least 50 ml within 10 minutes. 2 The swelling layer area is at least 30 g, more preferably at least 35 g, still more preferably at least 38 g, and most preferably at least 40 g of Ringer's solution.

[0099] The amount of liquid released by the swollen layer or the wound treatment product (in the sense of the intended wound cleansing effect) can be at least 8% by weight, more preferably at least 10% by weight, still more preferably at least 13% by weight, and most preferably at least 15% by weight of the maximum absorbent capacity of the swollen layer or the wound treatment product. The method for determining the amount of liquid released is reproduced in the examples.

[0100] The liquid retention capacity of the swollen layer or the wound treatment product can be at least 60% by weight, more preferably at least 70% by weight, still more preferably at least 80% by weight, and most preferably at least 90% by weight of the maximum absorbable capacity of the swollen layer or the wound treatment product. The method for determining the liquid retention capacity is reproduced in the examples.

[0101] Which of these values ​​is most suitable depends on the type of wound being treated. The more extensively a wound is covered by a surface (such as a fibrinous surface), necrotic tissue, or biofilm, the more it benefits from high-intensity irrigation, making a high saturation value of 80% or greater recommended in such cases. Conversely, those product variants with lower saturations between 50% and 70% can be used to treat uninfected wounds with greater exudation.

[0102] The given saturation values ​​will be explained below with examples: when the swelling layer can absorb a maximum of 100 ml of aqueous salt solution (osmotic pressure value in the isotonic range, i.e., 9 g NaCl in one liter of H2O), the swelling layer is 50% saturated after absorbing 50 ml.

[0103] In addition, the saturation value given can be relative to a wound treatment product having three main layers (a protective layer, a swelling layer, a liquid-permeable layer, and an adhesive layer in between) or relative to the entire wound treatment product that may have additional layers (such as a backing layer) as needed.

[0104] Additionally, it can be determined that this wound care product is unsuitable for or incompatible with negative pressure therapy because, for example, the wound care product does not have a port that can be used to apply negative pressure to the product or the wound beneath the product.

[0105] Within the scope of this invention, it can be proposed that the wound treatment product does not contain superabsorbent particles. Preferably, it contains no particles that may fall off after the product is cut. This excludes adhesive particles that may be used during the preparation of the product, as these adhesive particles are bonded to the remaining material and do not impede the desired cutability. The inventive concept also does not exclude effective substance particles that dissolve in an aqueous salt solution.

[0106] The salt present in this aqueous salt solution may be NaCl. This aqueous salt solution is preferably isotonic. Such isotonic salt solutions have essentially the same osmotic pressure as human blood. A small deviation of 1% upward or downward in Pascals is tolerable and also falls within the scope of the term "isotonic solution."

[0107] This aqueous salt solution contains other salts besides NaCl, such as KCl, or, for example, a combination of KCl and NaCl. A preferred variant of this aqueous salt solution is the so-called Ringer's solution, which contains CaCl in addition to NaCl and KCl and is isotonic.

[0108] Isotonic solutions offer the advantage that unprotected cells in the open area of ​​the wound being treated are not exposed to osmotic stress. Instead, the minerals contained in the saline solution positively influence cellular metabolism. Thus, human cells are able to absorb minerals from the environment through membrane proteins such as aquaporins.

[0109] In this sense, aqueous salt solutions can contain NaCl, KCl, and CaCl.

[0110] The aqueous salt solution stored in the swelling layer can be transferred from the swelling layer to the remaining layers of the wound treatment product. This aqueous salt solution can be present, in particular, in the protective layer and the permeable liquid layer. This does not affect the product's operation. Ideally, the solution will pass through the permeable liquid layer at least after application to the wound. The absorption capacity of the remaining layers can be taken into account when determining the amount of solution required to wet the swelling layer.

[0111] The invention will now be explained in detail with the aid of exemplary drawings, wherein variations shown may be modified according to the application purpose with the aid of the technical information contained herein.

[0112] Figure 1 An embodiment of the wound treatment product according to the invention is shown in cross-section. This wound treatment product is adhesive to a wound and / or skin and also has a liquid-permeable backing. This variant is particularly well-suited for treating plantar ulcers.

[0113] Figure 2 The top view shows the cropped form. Figure 1 Products.

[0114] Figure 1 and Figure 2The diagram illustrates a wound treatment product (9) according to the invention, comprising an upper backing (5) that minimizes the leakage of aqueous saline solution (not shown) from the swelling layer (3) in the distal direction and simultaneously serves as a support layer for the wound treatment product (9). The backing (5) is secured to a protective layer (1) formed of nonwoven fabric by means of an adhesive layer (2). The protective layer (1) is connected to the swelling layer (3) by means of the adhesive layer (2). A proximal, liquid-permeable layer (4) is secured below the swelling layer (3) by means of the adhesive layer (2). The liquid-permeable layer (4) is covered in the proximal direction by a perforated adhesive carrier. The perforated adhesive carrier consists of an adhesive layer (2), a PU foil (6), and a non-invasive silicone adhesive layer (7), which forms a connection with the liquid-permeable layer (4). The perforated adhesive carrier has perforated openings (8) over its entire surface area, which pass through the silicone adhesive (7), the PU film (6), and the adhesive layer (2). The product can be fixed to the skin, wound, or wound edges by means of the silicone adhesive (7), where the PU foil and silicone adhesive serve as the wound contact layer. Figure 2 In the illustration, the wound treatment product (10) is cut into two halves (fragments) in the middle. The structural units and functionality of each half remain unchanged.

[0115] Figure 3 The fluid release of the wound treatment product according to the invention and the control wound dressing over 24 hours and 72 hours is shown in a bar graph. The wound treatment product is represented by solid black bars, and the control group by hollow bars. Other details can be found in the related embodiments.

[0116] Figure 4 The liquid retention capacity (reserve rate) of the wound treatment product according to the invention is illustrated by means of a bar graph. Other details can be found from the relevant embodiments.

[0117] Figure 5 The absorption capacity of the wound treatment product according to the invention and the control wound dressing is shown in a bar graph. The wound treatment product is represented by solid black bars, and the control group is represented by hollow bars.

[0118] Example

[0119] The present invention will now be explained in detail with reference to the embodiments.

[0120] Example 1: Preparation of an adhesive wound treatment product for application to the skin surface

[0121] First, a swollen layer (3) is provided as a product sold by the meter. A liquid-permeable layer (4) in the form of PP nonwoven fabric is applied to the bottom surface of the swollen layer (3). A protective layer (1) also composed of PP nonwoven fabric is applied to the top surface of the swollen layer (3). To bond these layers together, adhesive particles in the form of biodegradable polyester are applied between these layers. The adhesive particles are bonded together in a subsequent heat curing process. This is accomplished by heat treatment in a drying oven at a temperature greater than 120°C and subsequent rolling. The molten adhesive particles form adhesive layers (2). The resulting laminate, consisting of three layers, has a thickness of 2.3 mm and a density of 260 g / m³. 2 Weight per unit area.

[0122] The laminate is wound onto a roll and hung in a converter. In the next step, a backing layer (5) formed of PU is applied to the upper side (distal side in the case of a wound treatment product) of the laminate using an acrylic adhesive. Additionally, a perforated adhesive carrier is applied proximally to the fluid-permeable layer. This adhesive carrier consists of a PU foil (6) with its bottom surface coated with a skin-compatible and non-invasive silicone adhesive (7). The top surface of the PU foil is coated with an acrylic adhesive (2), which bonds the PU foil to the fluid-permeable layer. The PU foil and the acrylic adhesive together form the adhesive carrier. The silicone adhesive (7) and the PU foil (6) form the wound contact layer. Perforations (8) present in the adhesive carrier and the silicone adhesive ensure that fluid can pass through later.

[0123] To protect the silicone (7), it is covered with a release liner, which is removed just before the product is applied to the wound. The backing layer (5) is printed with information to indicate to the user later that this is the top surface of the product, thus simplifying the correct application.

[0124] In the next step, a square fragment with an area of ​​10 cm x 10 cm is separated from the stack. The separated product is then processed using a packaging machine. In the packaging machine, the dried product is spread out on a liquid-sealed foil. An aqueous saline solution is added, more precisely, in an amount that does not deplete the maximum absorbent capacity of the product (approximately 31 ml). The upper (liquid-sealed) packaging film is then used to seal the wound treatment product (9) between the lower and upper foils. The resulting bag and the product contained within it are then steam sterilized at 120°C. The now moist wound treatment product (9) in the bag (which is also part of the packaging material) is then sterilized. After being removed from the bag, the sterile product thus obtained can be applied to the wound to be treated.

[0125] Example 2: Cutting of wound treatment products

[0126] Using commercially available scissors, cut the wound treatment product (9) according to Example 1 in half at approximately the center (that is, about 5 cm from the left or right edge). The cutting process can be carried out in a way that is effortless and without special force. Visually evaluate the cut edges. It can be determined that there are no worn or loose fibers. The cut surface is flat, smooth, and straight.

[0127] Furthermore, the layers of the cut piece form a stable complex and show no tendency to separate, disintegrate, or delaminate. Thus, each individual cut piece is suitable for wound treatment.

[0128] Example 3: Measurement of maximum pressure load

[0129] A moist wound treatment product (9) of approximately two weeks old (but circular) according to Example 1 was provided and placed in a commercially available transparent plastic ZIP bag. The bag was sealed and placed in a Sensomative calibration device for further experimental procedures. The radially shaped wound treatment product (9) (in top view) had a diameter of 4.5 cm. Load cycles were then performed, in which a gravity of 188.5 N (corresponding to approximately 19 kg) was applied to the entire area of ​​the product (9) within 1 second. The gravity was maintained for one second and then reduced to 0 N within 2 seconds. The number of load cycles was ten. The process was carried out at a temperature between 22°C and 23°C. Gravity was transferred by means of an inflatable shell made of synthetic hermetically airtight material mounted in the calibration device. The shell was pneumatically filled during the load cycles.

[0130] After the load test, the product (9) was removed from the equipment. The product (9) and the bag were visually inspected. It was confirmed that there was no material breakage. All layers of the product (9) were structurally intact. After removing the product (9) from the bag, it was confirmed that there were no torn fibers or leaked gel at the product (9), and that there was no separated or leaked material in the bag lining. Only a small amount of aqueous salt solution remained in the bag.

[0131] Example 4: Determination of Liquid Discharge

[0132] The amount of fluid released is crucial for achieving the intended wound cleaning effect.

[0133] A swollen layer with a circular design and a diameter of 4.5 cm, as described in Example 1, was provided. As given in Example 1, this swollen layer contained Ringer's solution but was not saturated with it. After determining the weight (m1) of this swollen layer, it was laid flat on a hydrogel bandage (Baumann's "HydroTac Transparent™", cut to approximate the area of ​​the swollen layer). The swollen layer was in contact with the wound contact surface of the hydrogel bandage and thus with the hydrogel. The hydrogel bandage here mimics the plasticity and fluid absorption capacity of human tissue. The two components were then welded together into a vapor-proof foil. In the next step, a cardboard approximately the area of ​​the hydrogel bandage was placed on the welded assembly formed by the swollen layer and the hydrogel bandage. A water-filled conical flask was placed into the cardboard. The cardboard and the filled flask together had a weight of 250 g, simulating the compression pressure caused by a secondary bandage. The weight (m2) of the wound treatment product was measured after 24 and 72 hours. The liquid release was tested using a total of forty samples (twenty for each corresponding time period) and the average value was calculated.

[0134] The moist wound dressing with the following construction, as described in WO 2016 / 156619 A1, was used as a control group:

[0135] The wound dressing has an absorbent / washing body based on a nonwoven fabric, in which superabsorbent particles, combined with cellulose fibers and thermoplastic fibers, are contained in a thoroughly mixed manner. The absorbent / washing body has a sheath forming the outer visible side of the wound dressing. This sheath consists of a textile woven fabric on the wound-facing side and a nonwoven fabric layer on the wound-facing side. A liquid-impermeable plastic film layer exists between the nonwoven fabric layer and the absorbent / washing body. The woven fabric, absorbent / washing body, plastic film layer, and nonwoven fabric layer are not planarly connected to each other, but are fixed together only by welding connections along their circumferential edges. A control group was also saturated with Ringer's solution. Forty samples were tested, and the average value was determined.

[0136] The percentage of liquid released is obtained according to the following formula: 100% - (m2 x 100%) / m1.

[0137] The results are shown in Figure 3 middle.

[0138] Example 5: Determination of liquid retention capacity (retention rate)

[0139] Fluid retention is important to prevent the wound treatment product from being completely squeezed dry. For continuous material exchange between the wound treatment product and the wound in the sense of suction / washing action, residual fluid should be retained in the wound treatment product, even under pressure. The pressure of 35 mmHg applied during subsequent measurements corresponds to the force typically applied during compression therapy (e.g., commonly used in the treatment of venous insufficiency in lower extremity ulcers).

[0140] A swollen layer with a circular design and a diameter of 4.5 cm, as described in Example 1, was provided. As given in Example 1, the swollen layer contained Ringer's solution but was not saturated with it. The weight (m1) of the swollen layer was first measured. The swollen layer was then laid onto a grid. The grid was secured in the air using four identical spacers. A weight of 760 g was applied to the swollen layer. The swollen layer was reweighed after 10 minutes.

[0141] The retention rate is determined according to the following formula: (m² x 100%) / m 1。 Twenty samples were tested and the average of the measurements was calculated. The results were... Figure 4 As shown in the image.

[0142] Example 6: Determination of absorption performance

[0143] Absorption performance is a measure of the suction effect of the wound treatment product. This suction effect allows irritants, fibrin surfaces, and excess matrix metalloproteinases washed from the wound bed to be absorbed and encapsulated within the wound treatment product.

[0144] A wound treatment product (circular, 4.5 cm in diameter) as described in Example 1 was provided. As given in Example 1, the product contained Ringer's solution but was not saturated with it. After weighing, the product was placed in a dryer filled with a desiccant. The dryer was filled with a 0.9% NaCl solution in water. The dryer was turned off and a vacuum was applied for 30 minutes. After the time elapsed, the product was removed and hung for 5 minutes to drain. The weight of the product was then measured again. Measurements were performed on a total of ten products, and the average value was determined.

[0145] To determine the comparison values, ten control wound dressings as described in Example 4 were measured in the same manner, and the average value was also determined. The results are presented in... Figure 5 middle.

Claims

1. A cuttable wound treatment product (9), comprising: a) A liquid-permeable layer with a nonwoven fabric laid on the proximal side (4). b) A protective layer with a nonwoven fabric laid on the distal side (1). c) A swollen layer (3) in the form of a nonwoven fabric containing polymer-containing superabsorbent fibers, laid between the proximal, liquid-permeable layer (4) and the distal, protective layer (1), wherein the superabsorbent fibers are present in the form of a felt together with at least one other type of fiber. d) An aqueous salt solution, which is stored in the swollen layer (3), has a pH of < 7.0 in the storage state, and can be released to the wound during wound treatment. The proximal, liquid-permeable layer (4), the swelling layer (3), and the distal, protective layer (1) have identical cuts and adhere to each other without protrusions, and the wound treatment product (9) is designed to be seamless.

2. The cutable wound treatment product (9) according to claim 1, wherein the wound treatment product (9) has a strength of at least 8 kg / 100 cm. 2 Its pressure resistance allows the wound treatment product (9) to undergo elastic deformation only when subjected to such pressure.

3. The cuttable wound treatment product (9) according to claim 1 or 2, wherein the additional type of fiber is selected from the group consisting of: cellulose-containing fibers, polyester-containing fibers, preferably polyethylene terephthalate and / or polyamide, and wherein the additional type of fiber is needle-punched together with the polymer-containing superabsorbent fiber to exist in the form of needle felt.

4. The cuttable wound treatment product (9) according to any one of the preceding claims, wherein the nonwoven fabric of the proximal liquid-permeable layer (4) and / or the distal protective layer (1) comprises thermosetting fibers.

5. The cuttable wound treatment product (9) according to claim 4 above, wherein the thermosetting fiber comprises or is composed of one or more polymers selected from the group consisting of: Polypropylene, polyvinyl chloride, polyethylene, polyethylene terephthalate, polycarbonate, polyamide, polyurethane, polystyrene and mixtures thereof.

6. The cuttable wound treatment product (9) according to any one of the preceding claims further comprises a backing layer (5) laid distally relative to the protective layer (1), the backing layer preferably comprising polyurethane.

7. The cuttable wound treatment product (9) according to claim 6, wherein the backing layer (5) is elastically printable and liquid-permeable, and wherein the MVTR is less than 1000 g / m 2 / 24h.

8. The cuttable wound treatment product (9) according to any one of the preceding claims, wherein the superabsorbent fibers in the swelling layer (3) comprise a transversely crosslinkable polymer, preferably an acrylate-containing polymer or an acrylate copolymer, wherein the transverse crosslinkability is preferably based on the formation of an ester compound.

9. The cuttable wound treatment product according to any one of the preceding claims, wherein the proximal liquid-permeable layer (4), the swelling layer (3), and the distal protective layer (1) are present as a laminate.

10. A cuttable wound treatment product (9) according to any of the preceding claims, wherein the proximal liquid-permeable layer (4), the swelling layer (3) and the distal protective layer (1) are planarly and non-detachably connected to each other, wherein the layers are preferably bonded to each other by hot melt adhesive, and wherein the hot melt adhesive preferably comprises or is composed of a polyolefin or copolymer.

11. A cuttable wound treatment product (9) according to any one of the preceding claims, wherein the structural integrity of the wound treatment product (9) remains unchanged during cutting, such that the fibrous or granular components of the wound treatment product (9) cannot be released through the felt structure of the swelling layer, especially the superabsorbent fibers.

12. A cuttable wound treatment product (9) according to any of the preceding claims, wherein the wound treatment product (9) has an additional silicone-containing wound contact layer (7) which is applied directly or in the form of a coated foil (6) to the outside of the liquid-permeable layer (4).

13. The cuttable wound treatment product (9) according to claim 12, wherein the silicone-containing wound contact layer (7) only partially covers the liquid-permeable layer (4) and is preferably perforated.

14. A cuttable wound treatment product (9) according to any one of the preceding claims, wherein the nonwoven fabric of the proximal, liquid-permeable first layer (4) and / or the protective layer (1) has a dry weight of 15 g / m². 2 Up to 50g / m 2 Weight per unit area.

15. The cuttable wound treatment product (9) according to any one of the preceding claims, wherein the proximal, liquid-permeable first layer (4) and the distal, protective layer (1) are composed of identical materials or identical mixtures of materials.

16. The cuttable wound treatment product (9) according to any one of the preceding claims, wherein the swelling layer (3) is not saturated with the salt solution stored therein.

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