Wound dressing for wound treatment in a moist or moist / wet environment

Abstract

The invention relates to a wound dressing (2) for wound treatment in a moist or moist / wet environment, having a fibrous nonwoven-based absorbing / rinsing body (4) in which superabsorbent material is received in a distributed manner, wherein a saline aqueous solution, in particular Ringer's solution, is applied to the absorbing / rinsing body (4) by the manufacturer, and having a cover (6) forming the outer visible sides of the wound dressing, wherein the cover (6) comprises, on the wound-facing side of the wound dressing, a textile surface material (9), in particular composed of a weft-knitted fabric, warp-knitted fabric or woven fabric, wherein the cover (6) has, on the wound-facing side of the wound dressing, an antimicrobial coating (22) which has been applied to part or all of the outer side and which comprises a hyaluronic acid and a polypeptide chosen from polyarginine, polylysine and polyornithine or a mixture of at least two of the aforementioned polypeptides.

Description

[0001] Wound dressing for wound treatment in moist or moist-wet conditions

[0002] milieu

[0003] The invention relates to a wound dressing for wound treatment in moist or wet environments, comprising a fiber-free absorbent / irrigating body in which superabsorbent material is distributed, wherein the absorbent / irrigating body is supplied by the manufacturer with a saline aqueous solution, in particular Ringer's solution. A covering forming the outer visible surfaces of the wound dressing comprises, on the wound-facing side of the dressing, a layer of a textile surface material, in particular a knitted, crocheted, or woven fabric.

[0004] Such a wound dressing is known from WO 2011 / 141454 A of the applicant. It is a wound pad-like or compress-like dressing that can be applied to a wound or used for packing deep wounds. The absorbent / irrigating element is filled by the manufacturer, in particular until saturated, with a saline aqueous solution, which causes the superabsorbent material to swell and transition into a gel-like state. This gives the absorbent / irrigating element a dual function in wounds with high exudate. Wound secretions, including their critical components such as germs, are actively absorbed and retained by the absorbent / irrigating element, which in turn releases the saline aqueous solution onto the wound, thus creating or supporting a moist wound environment.This supports wound cleansing and positive wound conditioning, thus positively influencing healing. This is referred to as interactive wet therapy, which is particularly favored for poorly healing wounds, clinically confirmed infected wounds, or chronic wounds of various origins, such as diabetic gangrene, pressure ulcers, or leg ulcers.

[0005] The aforementioned Ringer's solution is typically an aqueous solution containing sodium chloride, potassium chloride and calcium chloride (in particular 8.6 g NaCl, 0.3 g KCl and 0.33 g CaCl2j e litres).

[0006] Furthermore, wound dressings with antibiotic efficacy are known. These are generally based on the use of exogenous antimicrobial agents. While such dressings are effective against pathogenic microorganisms, they have the disadvantageous property of also affecting the body's own cells. Increased cytotoxicity for animal cells has been demonstrated using in vitro assays. The affected cells are stressed, and their vital signs decrease. At test concentrations that closely approximate real-world conditions, some of the cells in the assay typically die. EP 2 371 335 Bl describes an antibacterial wound dressing containing the active ingredient polyhexamethylene biguanide (PHMB). However, recent studies have shown that PHMB causes toxic effects in in vitro assays on human cells (Medical Mycology, 2017, Vol. 55, No. 3, pp. 334-343).In vivo experiments on rats also showed a serious potential for harm (Interdisciplinary Toxicology, 2015, Vol. 8, No. 4, pp. 193-202).

[0007] From EP 3 452 118 Bl, a polyelectrolyte coating is known which comprises at least one polycationic layer consisting of polypeptides and at least one polyanionic layer consisting of hyaluronic acid. The polyelectrolyte coating exhibits biocidal activity and can be used for the manufacture of antimicrobial medical devices, such as implants.

[0008] The present invention aims to provide a wound dressing for wound treatment in moist or moist-wet environments of the type described above, with improved antimicrobial properties. Furthermore, the wound dressing should be atraumatically removable from a wound and exhibit high biocompatibility.

[0009] This task is accomplished by a wound dressing with a fiber-free nonwoven absorbent / irrigating core and a covering forming the outer visible surfaces of the wound dressing, wherein the covering on the wound-facing side of the wound dressing comprises a textile surface material, in particular a knitted, crocheted, or woven fabric, and wherein the covering on the wound-facing side of the wound dressing has an antimicrobial coating applied partially or completely to the outside, which comprises hyaluronic acid and a polypeptide selected from polyarginine, polylysine, and polyornithine, or a mixture of at least two of the aforementioned polypeptides. Superabsorbent material is dispersed within the absorbent / irrigating core, which is supplied by the manufacturer with a saline aqueous solution, in particular Ringer's solution.

[0010] Because the antimicrobial coating is applied to the outer surface of the dressing, on the side facing the wound, the antimicrobial activity emanating from the hyaluronic acid and polypeptides can be utilized directly at the wound surface. This allows microorganisms and biofilms to be destroyed, as the antimicrobial coating is primarily effective in direct contact with the microorganisms. The antimicrobial activity of polyelectrolyte coatings consisting of polypeptides and hyaluronic acid is described in EP 3 452 118 B1. It has been found that when the antimicrobial coating comes into contact with the superabsorbent material in the absorbent / irrigating body, the polypeptides interact with the typically negatively charged superabsorbent material, thereby reducing the antimicrobial activity. Therefore, according to the invention, the antimicrobial coating is applied to the outer surface of the dressing.The antimicrobial coating is located on the textile surface material of the covering and has no direct contact with the absorbent / flushing body or the superabsorbent material.

[0011] Because the antimicrobial coating according to the invention forms a gel-like structure due to the hyaluronic acid, the textile surface material cannot bond with the wound or wound components. Tissue cannot grow into the textile surface material, nor can the textile surface material, and thus the wound dressing, adhere to the wound bed. Therefore, the wound dressing can be removed from the wound atraumatically. The use of ointment or silicone gel, which is usually necessary to achieve atraumatic properties, is not required with the present invention, as this function is fulfilled by the antimicrobial coating.

[0012] The wound dressing according to the invention is also suitable for treating wounds with antibiotic-resistant bacteria. While antibiotics are usually organic compounds that are broken down by resistant bacteria, for example, such an occurrence of resistance has not been observed with regard to the antimicrobial coating of the present invention.

[0013] Furthermore, the wound dressing according to the invention exhibits additional wound-healing properties resulting from the moisture-regulating properties of hyaluronic acid. Such effects are found in vivo in the extracellular matrix.

[0014] Surprisingly, it has been shown that the antimicrobial coating is permeable to wound exudate. This allows the antimicrobial coating to be applied to the entire surface or almost the entire surface of the textile material. However, the antimicrobial coating can also be applied only partially. This means that the antimicrobial coating only covers certain sections of the textile material or, for example, adheres only to threads or fibers of the textile material, leaving the openings and passages between the threads or fibers free of the antimicrobial coating.

[0015] According to the invention, a coating is also present if the coating is not continuous or fully covering the textile surface material. Even if only individual threads or

[0016] Fibers that have an antimicrobial coating are referred to as having an antimicrobial coating according to the invention.

[0017] According to the invention, the covering on the wound-facing side of the wound dressing comprises a textile surface material, in particular a knitted, woven, or twill fabric. Due to the openings and passages between the threads and loops, these materials allow fluid exchange between the wound and the absorbent / irrigating element. Wound exudate is actively absorbed by the absorbent / irrigating element, which in turn releases the saline aqueous solution to the wound. Because the textile surface material is provided with the antimicrobial coating, germs are not only killed on the wound surface, but recontamination by germs flushed out of the absorbent / irrigating element is also prevented.

[0018] Furthermore, a knitted fabric in particular has the advantage of giving the entire wound dressing a high degree of flexibility.

[0019] Hyaluronic acid and polypeptides such as polyarginine, polylysine, and polyornithine are substances that occur naturally in the human body and are produced by the body itself. Because the antimicrobial coating comprises these endogenous substances, the wound dressing according to the invention exhibits high biocompatibility.

[0020] The polypeptides used in the invention are polyarginine and / or polylysine and / or polyornithine. The polylysine can be α-poly-L-lysine and / or β-poly-L-lysine. The polylysine can, for example, have a molecular mass of 3.5 kDa to 4 kDa. Furthermore, the polylysine can comprise 11 to 50 subunits, preferably 15 to 35 subunits, and particularly preferably 20 to 30 subunits of lysine per molecule. Likewise, the polyarginine can comprise 11 to 50 subunits, preferably 15 to 35 subunits, and particularly preferably 20 to 30 subunits of arginine per molecule.

[0021] All of these polypeptides carry a net positive charge due to their chemical properties and can therefore have antimicrobial effects. Polyarginine also has the additional benefit of promoting wound healing by increasing the proportion of so-called M2 macrophages within the macrophage population. While M1 macrophages initiate inflammatory reactions and trigger the production of cytotoxic radicals, M2 macrophages have anti-inflammatory and proliferative effects and promote tissue closure.

[0022] Preferably, the coating according to the invention contains polyarginine. The use of such polyarginine-containing coatings according to the invention is advantageous even in non-infected wounds, as wound healing is accelerated.

[0023] Alternatively, the combination of polyarginine and polylysine is particularly preferred, as it exhibits a particularly pronounced antimicrobial effect in the coating, presumably due to a synergistic effect. The combination of polyarginine and polylysine is able to surpass the antimicrobial effect of either individual substance against various pathogens.

[0024] The polypeptides can have a substantially uniform chain length. A substantially uniform chain length exists when at least 90%, preferably at least 95%, particularly preferably at least 98%, and especially at least 99% of all polypeptides contained in the antimicrobial coating have the same chain length. This offers the advantage that the antimicrobial activity and the stability of the antimicrobial coating are easily controllable.

[0025] Preferably, the number of amino acids in the polypeptides is at least 10. Furthermore, the number of amino acids in the polypeptides is preferably at most 2000. Particularly preferred is a number of 10 to 100 amino acids, and especially 30 to 50 amino acids. This number refers to the number of amino acids per molecule of a polypeptide. Typically, these amino acids are linked together via peptide bonds.

[0026] According to a preferred embodiment of the invention, the polypeptides have a molecular mass of 1 to 41 kDa. Preferably, the polypeptides have a molecular mass of 2 to 40 kDa, particularly preferably 3 to 39 kDa, and particularly preferably 5 to 37 kDa.

[0027] Hyaluronic acid, also known as hyaluronan, is a heteropolysaccharide belonging to the glycosaminoglycans. The basic building block of hyaluronic acid is an aminodisaccharide composed of d-glucuronic acid and N-acetyl-d-glucosamine, forming an alternating (1^3)-(1^4)-β-glycosidic bond. Due to its chemical properties, hyaluronic acid molecules carry a net negative charge and are therefore classified as polyanions. Hyaluronic acid is water-binding and possesses tissue-regenerating and wound-healing properties.

[0028] Preferably, the hyaluronic acid used in this invention can have molar masses of approximately 50 to approximately 10 4The hyaluronic acid has a molar mass of 140 to 150 kg / mol, preferably hyaluronic acid with a molar mass of 140 to 150 kg / mol. Within the scope of this invention, it is also possible to use a mixture of hyaluronic acid molecules with different molar masses, in which case the molar mass can be specified as the average molar mass of all hyaluronic acid molecules in the mixture. For example, the average molar mass can be 143 to 146 kg / mol. Alternatively, all or substantially all hyaluronic acid molecules in the coating have the same molar mass.

[0029] Hyaluronic acid can exist as a polymer mixture of hyaluronic acid polymers with different chain lengths. The hyaluronic acid polymers in the polymer mixture can have a molecular weight of at least 10 kDa and at most 300 kDa.

[0030] Hyaluronic acid can be cross-linked or uncross-linked, with uncross-linked hyaluronic acid being preferred. Possible methods for cross-linking hyaluronic acids include the use of 1,4-butanediol diglycidyl ether (BDDE), enzymatic cross-linking (e.g., using transglutaminases), or physical cross-linking (e.g., by freezing, heating, ultrasound, or microwaves). One possible method for cross-linking hyaluronic acids is described in WO 2010 / 131175 A1.

[0031] Another advantage of hyaluronic acid in antimicrobial coatings is that the electrostatic and ionic interactions between negatively charged hyaluronic acid and positively charged polypeptides create a stable bond between the two. The hyaluronic acid can thus act as an anchor for the polypeptides. Conversely, the polypeptides can also anchor the hyaluronic acid. For example, on a positively charged textile material, the antimicrobial coating, which also contains positively charged polypeptides, can be stably bound to the textile material using the hyaluronic acid.

[0032] The antimicrobial coating may include other compounds or structural components. These may be positively charged, negatively charged, or charge-neutral.

[0033] According to one embodiment of the invention, an aqueous buffer solution can be provided in the antimicrobial coating. Examples of aqueous buffer solutions are citrate buffer, Ringer's solution, TRIS buffer, TE buffer, TBS buffer, and TBS-T buffer. Preferably, the buffer is a Tris-NaCl buffer. The concentration of the buffer in the solvent (e.g., water) can be, for example, 5 mmol to 300 mmol; preferably, the concentration is 10 mmol to 200 mmol.

[0034] In another preferred embodiment, the antimicrobial coating may contain a preservative or a stabilizer in an amount of 0.1 to 2% by weight. Examples of suitable preservatives are benzoic acid, sorbic acid, or parabens. Examples of suitable stabilizers are ascorbyl palmitate and tocopherol.

[0035] The content of polar liquids, particularly water, in the antimicrobial coating can range from 0.1 to 50 wt.%. In some cases, for example, when the coating is intended to be a gel, more than 50 wt.% of polar liquids may be desirable and beneficial. Preferably, the coating contains 1 to 45 wt.% polar liquids, better 3 to 40 wt.% polar liquids, and best 5 to 35 wt.% polar liquids. These concentrations refer to the final content in the antimicrobial coating after active or passive drying.

[0036] Preferably, the antimicrobial coating can have a layer thickness of 10 nm to 1000 nm. Other preferred layer thicknesses are between 50 nm and 900 nm, 100 nm and 800 nm, and 200 nm to 600 nm. Greater layer thicknesses result in the wound dressing exhibiting particularly pronounced atraumatic properties. Coatings with a thinner coating allow for faster fluid exchange between the wound and the absorbent / irrigating element.

[0037] According to another formulation, the hyaluronic acid and the polypeptide can be mixed within the antimicrobial coating. This means that the hyaluronic acid and the polypeptide are distributed almost homogeneously within the antimicrobial coating.

[0038] Alternatively, the polypeptide can also be embedded in a hyaluronic acid matrix.

[0039] The antimicrobial coating comprises, in one embodiment, at least one polypeptide layer, which contains the polypeptides and has a net positive charge, and at least one hyaluronic acid layer, which contains the hyaluronic acid and has a net negative charge. The at least one polypeptide layer and the at least one hyaluronic acid layer are stacked on top of each other and are bonded together, with the at least one polypeptide layer alternating with the at least one hyaluronic acid layer, thus forming a sequence of alternating layers.

[0040] The number of alternating layers can be even or odd. An even number of alternating layers is preferred because for every negatively charged layer, there is a positively charged layer available, and the opposite charges attract each other, resulting in a particularly stable coating.

[0041] Preferably, each hyaluronic acid layer and one polypeptide layer together form a bilayer. Preferably, the number of alternating layers is 20 to 100, more preferably 30 to 90, more preferably 40 to 80, and most preferably 50 to 70. Half of the layers consist of hyaluronic acid layers, and the other half consist of polypeptide layers.

[0042] Furthermore, it is preferred that the polypeptides are embedded in a hyaluronic acid matrix. This can be formed by having an odd number of alternating layers, with each outer layer being a hyaluronic acid layer.

[0043] The textile surface material can have an antimicrobial coating with a basis weight of, for example, 5 ng to 200 ng / cm². 2 The antimicrobial coating preferably has an areal weight of 10 ng to 150 ng / cm². 2, particularly preferably an areal weight of 15 ng to 130 ng / cm² 2 , especially a basis weight of 20 ng to 100 ng / cm² 2 and ideally 20 ng to 50 ng / cm² 2 The basis weight of the coating refers to the sum of the masses of polypeptide or polypeptides and hyaluronic acid.

[0044] Similarly, the basis weight of the polypeptide(s) in the coating can range from, for example, 1 ng to 180 ng / cm². 2 , preferably 2 ng to 100 ng / cm 2 and especially preferred 3 ng to 50 ng / cm² 2 The wound contact layer should be .

[0045] Furthermore, the basis weight of the hyaluronic acid in the coating can range from, for example, 1 ng to 180 ng / cm². 2 , preferably 2 ng to 100 ng / cm 2 and especially preferred 3 ng to 50 ng / cm² 2 The wound contact layer should be .

[0046] It proves advantageous if the nonwoven-based absorbent / rinsing body comprises cellulosic fibers, in particular a mixture of cellulosic fibers and thermoplastic fibers, in particular polyolefin fibers, especially polypropylene fibers or polypropylene / polyethylene fibers.

[0047] The basis weight of the fiber component of the absorbent / rinsing body is advantageously 20 to 500 g / m². 2 preferably 30-300 g / m² 2 , especially preferred 50-200 g / m² 2 .

[0048] Furthermore, it proves advantageous if the textile surface material is made of a thermoplastic material, in particular of polyolefin, especially of polypropylene.

[0049] According to a particularly preferred embodiment of the invention, the covering on the wound-facing side has an additional, partially and structurally applied, atraumatic silicone layer with a coverage of at most 70%. This ensures atraumatic removal of the wound dressing even after prolonged wear, should the hyaluronic acid have been absorbed by the body. Furthermore, it is advantageous if the coverage of the partially and structurally applied, atraumatic coating is 20–70%, particularly 25–50%, and especially 30–40%.

[0050] It is further advantageous if the partially and structurally applied atraumatic coating is striped. The stripes can be linear. They preferably run parallel or equidistant from each other. The width of a stripe is advantageously 1 to 3 mm. The distance between the stripes is advantageously 4 to 8 mm, particularly 4 to 6 mm. This ensures that the fluid exchange between the wound and the absorbent / irrigating element is not significantly impaired.

[0051] The invention, as well as further advantageous embodiments and developments thereof, are described and explained in more detail below with reference to the examples shown in the drawings. The features that can be derived from the description and the drawings can be applied individually or in any combination according to the invention.

[0052] They show:

[0053] Figure 1 is a schematic sectional view of an exemplary wound dressing according to the invention, Figure 2 is a fluorescence microscopic image of an exemplary textile surface material with antimicrobial coating,

[0054] Figure 3 shows a fluorescence microscopy image of an exemplary textile surface material without antimicrobial coating.

[0055] Figure 4 shows a diagram of the activity values ​​of an exemplary antimicrobial coating comprising polyarginine and

[0056] Figure 5 shows a diagram of the activity values ​​of an exemplary antimicrobial coating comprising polylysine.

[0057] Figure 1 shows a cross-sectional view of a wound dressing 2. It comprises an absorbent / irrigating element 4 based on a nonwoven fiber base. This fiber base is preferably a mixture of air-laid cellulose fibers (cellulose) and polypropylene fibers or polypropylene / polyethylene fibers. Superabsorbent polymer materials (SAP) in particle or fiber form are mixed into this fiber mixture as homogeneously as possible, with the SAP content of the total mass of the absorbent / irrigating element 4 preferably being 40–50 wt.%. The average particle size of the SAP particles is, for example, 150 to 850 pm (e.g., polyacrylate of the brand Favor pac 300 from Evonik Stockhausen GmbH).

[0058] The absorbent / irrigating body 4 is surrounded by a covering 6 forming the outer surfaces of the wound dressing, which is formed by a wound-facing covering layer 8 and two wound-away covering layers 10a, b. The wound-facing covering layer 8 is preferably a layer 9 made of a textile sheet material, such as a knitted fabric, preferably of polypropylene, although a woven or knitted fabric would also be advantageously conceivable, i.e., a covering layer made of threads or filaments with a textile bond that allows good fluid exchange between the absorbent / irrigating body 4 and the surrounding wound.

[0059] One of the wound-facing layers 10a is a nonwoven fiber layer 12, preferably made of polypropylene, which forms a visible side 14 of the wound dressing 2 facing away from the wound. The second layer 10b is formed by a fluid-impermeable plastic film layer 16, which is arranged directly below the nonwoven fiber layer 12, i.e., on the wound-facing side of the nonwoven fiber layer 12, between the nonwoven fiber layer 12 and the absorbent / irrigating element 4. These two wound-facing layers 10a, 10b are not bonded together over their entire surface; they do not form a laminate in the true sense. Instead, they lie loosely and slidably against each other over their surfaces, but are connected along a circumferential edge 18 or a

[0060] The peripheral area is connected to each other and to the other components of the wound dressing.

[0061] On the wound-facing outer surface 20 of the wound-facing covering layer 8, a partially or completely applied antimicrobial coating 22 is provided. This coating 22 comprises hyaluronic acid and a polypeptide selected from polyarginine, polylysine, and polyornithine, or a mixture of at least two of the aforementioned polypeptides. Through contact with the wound, the coating 22 exerts an antimicrobial effect and prevents tissue ingrowth into the wound dressing 2, thus allowing the wound dressing 2 to be removed atraumatically from the wound.

[0062] The wound dressing 2 is exposed to a saline aqueous solution. This solution is located within the absorbent / irrigating body 4. An antimicrobial substance may be added to this saline solution. This substance is cationic in moist or wet wound environments at pH values ​​in the slightly acidic to neutral range of pH 4 to 7.5. This cationic antimicrobial substance is attracted to the negative groups of the anionic superabsorbent material in such a way that it remains bound to the superabsorbent materials even during the fluid exchange operation of the absorbent / irrigating body 4, and is therefore largely prevented from being released into the wound environment. This prevents germs introduced into the absorbent / irrigating body 4 with wound exudate from multiplying, thus largely preventing recontamination towards the wound.

[0063] In an exemplary preferred composition of the wound dressing 2, the nonwoven base of the absorbent / irrigating body 4 consists of 33 g / m². 2 Cellulose fibers (cellulose) and 11 g / m³ 2 Polypropylene / polyethylene fibers as binding fibers. This fiber mixture contains 70 g / m². 2 The above-mentioned superabsorbent polymer materials (SAP) are homogeneously mixed in. The wound dressing 2 is activated or impregnated with sufficient Ringer's solution to essentially saturate the absorbent / irrigating body 4 with Ringer's solution. The outer covering 6 is designed as described above.

[0064] The antimicrobial coating 22 can be applied to the textile surface material 9, which is a knitted polypropylene fabric, either by a spraying process or layer by layer by an immersion process. The following solutions were provided for this purpose:

[0065] Table 1

[0066] MW = Molecular mass

[0067] Conc. = Concentration adjusted with Tris-NaCl buffer containing 150 mM NaCl, 10 mM tris(hydroxymethyl)-aminomethane (TRIS, Merck, Germany), pH 7.4. Example 1:

[0068] The textile material 9, namely a knitted polypropylene fabric, was alternately dipped into the solutions "PAR30" to apply a polypeptide layer of polyarginine and HA119 to apply a hyaluronic acid layer. After each dip, the textile material 9 was rinsed with Tris-NaCl buffer (150 mM NaCl, 10 mM tris(hydroxymethyl)-aminomethane, pH 7.4). In total, the textile material 9 was dipped into each solution 24 times, resulting in a sequence of 48 alternating layers, or 24 double layers. Subsequently, the textile material 9 was treated with the antimicrobial

[0069] Layer 22, consisting of 24 double layers of polyarginine / hyaluronic acid, was passively dried overnight at room temperature. The polyarginine contained in the resulting antimicrobial coating 22 was labeled with fluorescein isothiocyanate (FITC) and visualized under a confocal microscope.

[0070] Figure 2 shows a fluorescence microscopy image of the textile fabric 9 according to Example 1, coated with the antimicrobial coating 22. The fluorescent areas are shown in white. The antimicrobial coating 22 adheres to the fiber structure of the knitted fabric, indicating a stable coating of the textile fabric 9.

[0071] Figure 3 shows a fluorescence microscopy image of the uncoated textile surface material 9 as a control. No white fluorescent areas are visible.

[0072] Antimicrobial evaluation:

[0073] The wound dressings 2 according to the invention were subjected to an antimicrobial activity test according to ISO 20743:2021 (Owen L, Laird K. Development of a silver-based dual-function antimicrobial laundry additive and textile coating for the decontamination of healthcare laundry. J Appl Microbiol. 2021; 130(4): 1012-22). After 24 hours of contact time of the wound dressings with a Gram-negative culture of Pseudomonas aeruginosa (ATTC 27853) and / or a Gram-positive culture of Staphylococcus aureus (ATTC 25923), the number of dividing bacterial cells (CFU) on the textile surface material 9 was determined in comparison to a control without an antimicrobial coating.

[0074] Figure 4 shows the results of the antimicrobial activity test for wound dressings 2 according to Example 1, in which the textile surface material 9 was coated with 24 double layers of PAR30 / HA119 ("coated") compared to an uncoated wound dressing ("non-coated"). A solution of S. aureus served as a negative control ("neg."), and an antibiotic effective against S. aureus was added to the test substrate as a positive control ("pos."). The bacterial growth rate, normalized against the negative control, could be reduced to approximately 10% by the antimicrobial coating ("coated"). The uncoated wound dressings reduced bacterial growth by only about 40%. The addition of the antibiotic ("pos.") completely inhibited growth.

[0075] Example 2:

[0076] The textile surface material 9 of the wound dressing 2 was coated with s-PLL and HA144 according to Table 1 using a spray application method. Both solutions were simultaneously sprayed onto the textile surface material 9 via separate nozzles of a spray gun, creating a mixed layer of the antimicrobial coating 22 in which hyaluronic acid and polylysine are statistically distributed. A total of ten mixed layers were applied successively and then passively dried overnight at room temperature. Figure 5 shows the results of the test for antimicrobial activity for wound dressings 2 coated according to Example 2 using the spray application method. Wound dressings without an antimicrobial coating 22 are designated as "non-coated". The wound dressings 2 according to the invention coated using the spray application method are designated as "coated".The antimicrobial coating 22 with polylysine (s-PLL) and HA144 resulted in a reduction of CFU by more than five log levels after 24 hours for both S. aureus and P. aeruginosa compared to the uncoated control ("non-coated").

Claims

Claims 1. Wound dressing (2) for wound treatment in moist or wet environments, comprising a fiber fleece-based absorbent / irrigating body (4) in which superabsorbent material is distributed, wherein the absorbent / irrigating body (4) is supplied by the manufacturer with a saline aqueous solution, in particular Ringer's solution, and with a covering (6) forming the outer visible sides of the wound dressing, wherein the covering (6) on the wound-facing side of the wound dressing comprises a textile surface material (9), in particular made of a knitted, crocheted or woven fabric, characterized in that the covering (6) on the wound-facing side of the wound dressing has an antimicrobial coating (22) applied partially or completely to the outside, which comprises hyaluronic acid and a polypeptide selected from polyarginine, polylysine and polyornithine or a mixture of at least two of the aforementioned polypeptides.

2. Wound dressing (2) according to claim 1, characterized in that the polypeptides have a number of 10 to 100 amino acids, in particular 30 to 50 amino acids.

3. Wound dressing (2) according to claim 1 or 2, characterized in that the hyaluronic acid is present as a polymer mixture of polymers of hyaluronic acid with different chain lengths and the polymer mixture comprises polymers of hyaluronic acid with a molecular weight of at least 10 kDa and at most 300 kDa.

4. Wound dressing (2) according to one of the preceding claims, characterized in that the polypeptides have a molecular weight of 1 to 41 kDa.

5. Wound dressing (2) according to one of the preceding claims, characterized in that the polypeptide and the hyaluronic acid are mixed together within the antimicrobial coating (22).

6. Wound dressing (2) according to one of claims 1 to 4, characterized in that the antimicrobial coating (22) comprises at least one polypeptide layer, which includes the polypeptide and has a positive net charge, and at least one hyaluronic acid layer, which includes the hyaluronic acid and has a negative net charge, wherein the at least one polypeptide layer and the at least one hyaluronic acid layer are superimposed and connected to each other, wherein the at least one polypeptide layer alternates with the at least one hyaluronic acid layer, so that a sequence of alternating layers is formed.

7. Wound dressing (2) according to claim 6, characterized in that the number of at least one polypeptide layer and at least one hyaluronic acid layer in the antimicrobial coating (22) is 10 to 100.

8. Wound dressing (2) according to one of the preceding claims, characterized in that the antimicrobial coating (22) has a thickness of 10 nm to 1000 nm.

9. Wound dressing (2) according to one of the preceding claims, characterized in that the fiber fleece-based absorbent / irrigating body (4) comprises cellulosic fibers, in particular a mixture of cellulosic fibers and thermoplastic fibers, in particular polyolefin fibers, in particular Polypropylene fibers or polypropylene / polyethylene fibers, includes .

10. Wound dressing (2) according to one of the preceding claims, characterized in that the basis weight of the fiber content of the absorbent / irrigating body (4) is 20-500g / m² 2 amounts.

11. Wound dressing (2) according to one of the preceding claims, characterized in that the textile surface material (9) is made of a thermoplastic material, in particular of polyolefin or polypropylene.

12. Wound dressing (2) according to one of the preceding claims, characterized in that the textile surface material (9) has a positive net charge.

13. Wound dressing (2) according to one of the preceding claims, characterized in that the covering (6) further comprises on the wound-facing side a partially and structuredly applied atraumatic layer of silicone with a coverage of at most 70%.

14. Wound dressing (2) according to claim 13, characterized in that the degree of coverage of the partially and structured applied atraumatic silicone layer is 20 - 70%, in particular 25 - 50%, in particular 30 - 40%.

15. Wound dressing (2) according to claim 13 or 14, characterized in that the partially and structurally applied atraumatic layer of silicone is formed in a strip shape.

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