Island dressing for wound treatment, having an acrylate adhesive in the edge region and a silicone gel in the wound-contacting region

Abstract

The present invention relates to a dressing (1, 13, 19, 22, 23, 24) for wound treatment, the dressing comprising an adhesive backing layer (2, 3), a wound pad (4), and a siliconised wound-contact layer (5, 6, 7). The invention provides an island dressing for wound treatment, which dressing is able to adhere well to the wound site but can also be removed again therefrom without causing pain and without damaging the wound surface. In preferred embodiments, the dressing is also provided for use in negative pressure wound therapy.

Description

[0001] Title: Island dressing for wound treatment with an acrylate adhesive in the peripheral area and a silicone gel in the wound contact area

[0002] Description

[0003] The present invention relates to a dressing for wound treatment. The dressing comprises a backing layer and a first adhesive layer arranged on a wound-facing side of the backing layer. The dressing further comprises a wound pad and a wound contact layer. The wound pad is arranged between the backing layer and the wound contact layer. The backing layer with the first adhesive layer projects beyond both the wound pad and the wound contact layer, so that the dressing has a first adhesive edge consisting of the backing layer and the first adhesive layer. The present invention also relates to a kit and a system for negative pressure wound therapy using the above-described dressing.

[0004] Wound dressings with a perforated, silicone-adhesive-coated wound contact layer are known in the art. The perforated, silicone-coated wound contact layer can cover the entire wound-facing side of the dressing. The dressing is then secured to the patient's body with the silicone adhesive. Such dressings are also used for negative pressure wound therapy.

[0005] Silicone adhesives are typically weakly adhesive and atraumatic. They may adhere weakly to dry skin in the peri-wound area, but usually not to the wound surface. Wound dressings of this type therefore have the distinct advantage of being painless and removable without damaging the wound or the intact peri-wound skin.

[0006] However, such siliconized wound dressings can sometimes detach prematurely from the wound site. This is due to the previously mentioned low adhesive strength of silicone adhesives. The low adhesive strength of silicone adhesives can be particularly disadvantageous when the dressing is used as part of negative pressure wound therapy. In this form of wound treatment, the dressing must fit the wound site airtight and must not leak. Otherwise, the desired negative pressure cannot be established in the wound space.

[0007] To solve the problem described above, the aforementioned dressings can additionally be secured and sealed to the wound site with adhesive strips along their edges. This is described, for example, in WO 2011 / 144888 A1 and shown in Figure 24D. However, applying the adhesive strips represents an additional step for nursing staff. It would be desirable if secondary dressing materials such as the adhesive strips proposed in WO 2011 / 144888 A1 could be dispensed with without the dressings prematurely detaching from the wound site or becoming leaky. This could reduce the burden on nursing staff and allow for more cost-effective patient treatment.

[0008] The object of the present invention was to provide an improved dressing for wound treatment, in particular for negative pressure wound therapy. The dressing should adhere well to the wound site so that the dressing does not develop any leaks during wound treatment and cannot detach from the wound site prematurely. Additional secondary dressing materials for attachment and sealing, such as the aforementioned adhesive strips, should be eliminated as far as possible for the new dressing so that the dressing can be applied more simply, quickly, and cost-effectively. At the same time, the dressing should be as easy to remove from the wound site as possible so that the dressing can be changed as painlessly as possible and without damaging the wound surface.The above objects were achieved with a dressing for wound treatment according to claim 1, a kit for negative pressure wound therapy according to claim 22 and a system for negative pressure wound therapy according to claim 23.

[0009] The dressing according to the invention comprises a backing layer and an adhesive layer arranged on a wound-facing side of the backing layer. The adhesive layer of the backing layer is also referred to herein as the "first adhesive layer." Furthermore, the dressing comprises a wound pad and a wound contact layer.

[0010] The wound pad is arranged between the backing layer and the wound contact layer. The backing layer with the first adhesive layer extends beyond both the wound pad and the wound contact layer, so that the dressing has an adhesive edge consisting of the backing layer and the first adhesive layer. The adhesive edge of the dressing is also referred to herein as the "first adhesive edge." The dressing according to the invention is therefore designed in the manner of an island dressing.

[0011] The dressing according to the invention is characterized by a special structure of the wound contact layer and a special adhesive combination. The first adhesive layer consists of an acrylate adhesive. Furthermore, the wound contact layer consists of a perforated carrier film, on the wound-facing and non-wound-facing sides of which an adhesive layer is arranged. The wound-facing adhesive layer of the carrier film is also referred to herein as the "second adhesive layer." The second adhesive layer consists of a silicone gel. The non-wound-facing adhesive layer of the carrier film is also referred to herein as the "third adhesive layer." Like the first adhesive layer, the third adhesive layer consists of an acrylate adhesive. The third adhesive layer has the particular function of bonding the wound contact layer to the wound pad.The perforations in the carrier film of the wound contact layer are not sealed by the second and third adhesive layers. The perforations thus penetrate all layers of the wound contact layer, allowing wound exudate to penetrate the dressing and transmit pressure to the wound surface.

[0012] Acrylate adhesives can exhibit high adhesive strength and are typically less expensive than silicone adhesives. By having an edge coated with an acrylate adhesive, the dressing according to the invention can adhere well to the wound site. As a result, additional secondary dressing materials for securing and sealing the present dressing are generally not required. Thanks to the siliconized wound contact layer, the dressing according to the invention can be removed from the wound site without causing pain or damaging the wound surface. Furthermore, the wound contact layer containing the silicone gel can contribute to the adhesion of the dressing to dry, intact skin in the peri-wound area. The dressing according to the invention can also contain smaller amounts of the expensive silicone adhesive, since the siliconized wound contact layer only forms part of the wound-facing side of the dressing.Overall, the present dressing allows for simple, quick, cost-effective, and gentle wound treatment. Further advantages of the dressing according to the invention emerge from the preferred embodiments of the invention specified below.

[0013] The terms "wound-facing" and "non-wound-facing" refer to the intended position of the dressing on the patient's body. The wound-facing side of a layer of the dressing is the side that faces the wound when the dressing is used as intended. Typically, the wound-facing side is the underside. Similarly, the non-wound-facing side of a layer of the dressing is the side that faces away from the wound when the dressing is used as intended. Typically, the non-wound-facing side is the top side.

[0014] The backing layer is the outermost layer of the dressing. It separates the dressing from the outside, protects the wound from contamination, and secures the dressing to the wound site with the first adhesive. The backing layer can be a closed, continuous layer. However, if the dressing is intended for negative pressure wound therapy, the backing layer advantageously has an opening for the extraction of air during negative pressure wound therapy. The opening allows the dressing to be brought into fluid communication with a negative pressure source. Since the backing layer supports the first adhesive layer, the opening in the backing layer also extends to the first adhesive layer. This means that the opening is present in both the backing layer and the first adhesive layer. The opening can, for example, be essentially round and have a diameter of 0.5 to 2.5 cm.

[0015] The backing layer can be made of various materials. For example, the backing layer can consist of a nonwoven fabric or a liquid-impermeable, water vapor-permeable plastic film. The plastic film embodiment is particularly preferred when the dressing is intended for negative pressure wound therapy. The liquid-impermeable, water vapor-permeable plastic film can be made of polyurethane, for example.

[0016] Preferably, the wound-facing side of the backing layer is fully coated with the first adhesive layer. The wound pad can then be easily attached to the backing layer. Alternatively, however, it is also possible for the wound-facing side of the backing layer to be coated with the first adhesive only in the area of ​​the first adhesive edge. In this case, the wound pad can be enclosed and held in place in the dressing with the wound contact layer. This is described in more detail below in connection with the second adhesive edge. If only the edge of the backing layer is adhesively coated, the dressing can be more breathable. The adhesive strength of the first adhesive layer can be more than 2.8 N / 25 mm, preferably more than 3.5 N / 25 mm, and particularly preferably more than 4 N / 25 mm. To ensure that the dressing does not adhere too strongly to the wound site, the adhesive strength of the first adhesive layer is preferably no more than 12 N / 25 mm.The bond strength of the first adhesive layer can be determined according to DIN EN ISO 29862:2019 (method 1), whereby deviations from the standard are possible in the following points:.

[0017] • Polypropylene plates (PP plates) are used as the substrate instead of steel plates. The PP plates can have dimensions of 150 mm x 50 mm x 4 mm and can be designed as disposable test specimens, with the test side covered with film. The film is removed before the test. The PP plates can correspond to the steel plates specified in the standard in terms of their surface finish. Accordingly, the PP plates are also typically completely flat and have a smooth (test) surface.

[0018] • The sample width is 25 mm instead of 24 mm.

[0019] • The waiting time is 20 min instead of < 1 min (i.e. the sample is only measured 20 min after it has been applied to the PP plate).

[0020] • If necessary, an extension tape is used if the sample is too short (for example, the tape Scotch 8959).

[0021] • If necessary, a reinforcing tape is used if the sample is elastic (for example the tape Tesa 4104).

[0022] To determine the bond strength of the first adhesive layer, a tensile testing machine according to DIN EN ISO 7500-01:2018-06, Class 1, can be used. The measurement results can be evaluated according to DIN ISO 6133:2017-04 (Method B).

[0023] In addition, the thickness of the first adhesive layer can be 20 pm to 60 pm.

[0024] As is typical for island dressings, the (first) adhesive edge of the dressing serves to secure the dressing to the wound site. The first adhesive edge is intended to be attached exclusively to intact skin in the peri-wound area. Accordingly, the first adhesive edge should not touch the wound. The first adhesive edge can, for example, have a width of 1.5 cm to 5 cm.

[0025] According to the invention, the present dressing further comprises a wound pad. Depending on the intended use of the dressing, the wound pad can be designed in very different ways. Preferred features and variants of the wound pad are specified in the following embodiments. Typically, the wound pad is arranged substantially centrally in relation to the backing layer in the dressing. Furthermore, the wound pad can be single-layered or multi-layered. In particular, the wound pad comprises one or more layers selected from the group consisting of an absorbent layer, a pressure-distributing layer, and a fluid-distributing layer. The function and preferred embodiments of these three different layers are described below.

[0026] An absorbent layer can absorb and retain fluid. Therefore, if the wound pad contains an absorbent layer, the dressing can absorb and retain wound fluid. The absorbent layer is usually hydrophilic. It can be made of, for example, a hydrophilic nonwoven fabric or a hydrophilic foam.

[0027] The hydrophilic nonwoven fabric of the absorbent layer preferably comprises alginate fibers, cellulose-based fibers, and / or a superabsorbent polymer (SAP) in the form of fibers. The cellulose-based fibers can be cellulose fibers or viscose fibers. The superabsorbent polymer can, in particular, be a polyacrylate. Polyacrylates can bind very large amounts of liquid and are therefore particularly advantageous materials for the absorbent layer.

[0028] The hydrophilic foam of the absorbent layer is preferably an open-cell foam. The hydrophilic foam of the absorbent layer is preferably made of polyvinyl alcohol or polyurethane.

[0029] In a preferred embodiment of the invention, the absorbent layer consists of a hydrophilic nonwoven fabric, wherein the nonwoven fabric comprises cellulose-based fibers, in particular cellulose fibers or viscose fibers, and polyacrylate fibers. Alternatively, it may also be preferred if the absorbent layer consists of a hydrophilic, open-cell foam made of polyvinyl alcohol or polyurethane.

[0030] The absorbent layer can also be further specified with regard to its absorption capacity. For example, the absorbent layer can have an absorption capacity of 50 g / 100 cm 2 up to 300 g / 100 cm 2 , preferably 50 g / 100 cm 2 up to 250 g / 100 cm2 , more preferably 100 g / 100 cm 2 up to 250 g / 100 cm 2 and particularly preferably 140 g / 100 cm 2 up to 220 g / 100 cm 2 The absorption capacity of the absorbing layer can be determined according to DIN EN 13726-1:2002-06 (Chapter 3.2).

[0031] A pressure-distributing layer according to the present invention can distribute negative pressure within the dressing. Air and fluid can be drawn out of the pressure-distributing layer when the layer is exposed to negative pressure. Therefore, if the wound pad contains a pressure-distributing layer, the dressing can be particularly well-suited for negative pressure wound therapy. The pressure-distributing layer is preferably hydrophobic. The pressure-distributing layer can consist, for example, of a spacer fabric, a woven fabric, a 3D-structured plastic film, or a hydrophobic, open-cell foam.

[0032] The 3D-structured plastic film of the pressure-distributing layer preferably has a plurality of perforations, with at least some of the perforations forming raised portions. The 3D-structured plastic film of the pressure-distributing layer can be made, in particular, of polyethylene or polyurethane. Such plastic films with a three-dimensional structure and a smooth and a roughened side are known from the international patent application WO 2013 / 034263 A1. Their use as a pressure-distributing layer is also described in the German patent application with the application number DE102022133930.0.

[0033] The hydrophobic, open-cell foam of the pressure-distributing layer is preferably made of polyurethane. In a preferred embodiment of the invention, the pressure-distributing layer is therefore made of a hydrophobic, open-cell polyurethane foam. A suitable hydrophobic, open-cell polyurethane foam is disclosed, for example, in WO 2012 / 022485 A1.

[0034] Advantageously, the pressure-distributing layer can have an air permeability of 1000 l / (m 2 sec) to 8500 l / (m 2 sec), preferably 1500 l / (m 2 sec) to 6000 l / (m 2 sec), more preferably 2000 l / (m 2 sec) to 5000 l / (m 2 sec), particularly preferably 2300 l / (m 2 sec) to 4000 l / (m 2 sec) and especially of 2400 l / (m 2 sec) to 3300 l / (m 2 sec). The air permeability of the pressure-distributing layer can be measured according to DIN EN ISO 9237 (20 mm test thickness, 20 cm2 test area, 200 Pa differential pressure).

[0035] A fluid-distributing layer, as its name suggests, can distribute fluid. The fluid is distributed within the layer, in particular by means of wicking. If the wound pad contains a fluid-distributing layer, fluid such as wound exudate can be better distributed within the wound pad, and the absorption capacity of an absorbent layer contained in the wound pad can be better utilized. It is therefore particularly advantageous to provide a fluid-distributing layer in the wound pad if the wound pad comprises an absorbent layer. The fluid-distributing layer is preferably hydrophilic. It can consist, for example, of a hydrophilic nonwoven fabric. The hydrophilic nonwoven fabric preferably comprises cellulose-based fibers, in particular cellulose fibers or viscose fibers.

[0036] The present invention provides that the fluid-distributing layer can absorb and distribute fluid, but also easily release it again. However, superabsorbent polymers can bind fluids very strongly. Accordingly, the fluid-distributing layer advantageously does not comprise a superabsorbent polymer, in particular polyacrylate. Furthermore, if the wound pad comprises both an absorbent and a fluid-distributing layer, the fluid-distributing layer typically has a lower absorption capacity than the absorbent layer.

[0037] The liquid-distributing layer can have an absorption capacity of 1 g / 100 cm 2 up to 50 g / 100 cm 2 , preferably 1 g / 100 cm 2 up to 40 g / 100 cm 2 , more preferably 1 g / 100 cm 2 up to 25 g / 100 cm 2 , particularly preferably 1 g / 100 cm 2 up to 10 g / 100 cm 2 and in particular 1 g / 100 cm2 up to 7 g / 100 cm 2 The absorption capacity of the liquid-distributing layer can be determined according to DIN EN 13726-1:2002-06 (Chapter 3.2).

[0038] With regard to the number and type of layers in the wound pad, the following variants are proposed as examples. In a simple single-layer embodiment of the invention, the wound pad consists of an absorbent layer. The dressing can then be particularly suitable for classic wound treatment, i.e. wound treatment without the use of negative pressure, for wounds with low to moderate exudation. According to a further simple single-layer embodiment of the invention, the wound pad consists of a pressure-distributing layer. The dressing can then be particularly suitable for negative pressure wound therapy, whereby the wound fluid is collected in a container outside the dressing and the dressing therefore does not necessarily have to contain an absorbent layer.In an advantageous two-layer variant, the wound pad can consist of an absorbent layer and either a pressure-distributing layer or a fluid-distributing layer. The wound pad can be arranged in the dressing such that the absorbent layer adjoins the wound contact layer, and the pressure-distributing or fluid-distributing layer adjoins the backing layer or the first adhesive layer. Simply put, the pressure-distributing or fluid-distributing layer is then arranged above the absorbent layer in the dressing. Alternatively, the wound pad can be arranged in the dressing such that the absorbent layer adjoins the backing layer or the first adhesive layer, and the pressure-distributing or fluid-distributing layer adjoins the wound contact layer.Simply put, the absorbent layer is placed above the pressure-distributing or fluid-distributing layer in the dressing. A dressing with an absorbent and pressure-distributing layer may be particularly suitable for negative pressure wound therapy, where the wound fluid is to remain within the dressing and a small negative pressure source is used without a secretion collection container. A dressing with an absorbent and fluid-distributing layer may be particularly suitable for the treatment of heavily exuding wounds without the use of negative pressure.

[0039] In a particularly advantageous three-layer version, the wound pad can consist of an absorbent layer and either two pressure-distributing layers or two fluid-distributing layers. The absorbent layer is arranged between the two pressure-distributing or fluid-distributing layers. Similar to what was previously described in connection with the two-layer embodiment, the combination of one absorbent and two pressure-distributing layers is intended in particular for negative pressure wound therapy without a secretion collection container, and the combination of one absorbent and two fluid-distributing layers is intended in particular for the treatment of heavily exuding wounds without negative pressure. However, compared to the two-layer variant of the wound pad, the present three-layer embodiment can distribute the negative pressure or the fluid even better within the dressing.

[0040] If the wound pad has a multi-layer structure, the layers can be essentially the same size and placed on top of one another. The layers can be bonded to one another over their entire surface, so that the wound pad is designed in the manner of a laminate. However, it can also be advantageous if the wound pad is designed like a pocket. Accordingly, an embodiment is proposed in which the wound pad comprises a cover and an absorbent core located in the cover. The cover can consist of two nonwoven layers, wherein the nonwoven layers are bonded to one another in their edge regions and thereby form a pocket in which the absorbent core is accommodated. The nonwoven layers are preferably bonded with an ultrasonic weld. The absorbent core comprises in particular cellulose and a superabsorbent polymer in the form of particles, in particular polyacrylate particles.Because the absorbent core is encased, the SAP particles, which are preferably loosely embedded in the pulp, cannot escape from the wound pad. The cover thus ensures the structural integrity of the wound pad. One or both of the aforementioned nonwoven layers of the cover can preferably also represent a fluid-distributing layer within the meaning of the present invention.

[0041] The following section discusses the siliconized wound contact layer of this dressing in more detail. The wound contact layer is typically positioned essentially centrally in relation to the backing layer in the dressing. Furthermore, the wound contact layer is usually designed to be at least as large as the wound pad so that it can completely cover the wound-facing side of the wound pad.

[0042] In one embodiment of the invention, the wound contact layer and the wound pad are substantially the same size and are substantially flush. The wound pad with the wound contact layer can then be attached to the backing layer with the first adhesive layer. This embodiment is easy to manufacture and cost-effective.

[0043] Alternatively, the wound contact layer can extend beyond the wound pad, so that the wound contact layer has an adhesive edge. The adhesive edge of the wound contact layer is also referred to herein as the "second adhesive edge." The second adhesive edge is at least partially bonded to the backing layer or the first adhesive layer, respectively, so that the backing layer and the wound contact layer can form a pocket for receiving the wound pad. In this embodiment, the wound contact layer can hold the wound pad in the dressing. It is then possible to apply an adhesive coating to the backing layer only in its edge region to make the dressing more breathable. Furthermore, it is then possible for the wound pad to be formed from several layers that are simply placed on top of one another. This makes it easy to provide a multi-layer wound pad that is highly variable in terms of its composition.The layers of the wound pad, which are only loosely placed on top of each other, cannot separate from each other because the backing layer and the wound contact layer enclose the wound pad.

[0044] Furthermore, the wound contact layer can constitute 30% to 90%, preferably 30% to 80%, more preferably 30% to 70%, and particularly preferably 50% to 70% of the wound-facing side of the dressing. The open area in the wound contact layer created by the perforations can be disregarded. Furthermore, the carrier film of the wound contact layer can be made of polyurethane. The thickness of the carrier film of the wound contact layer can, for example, be approximately 25 μm.

[0045] Silicone gels for wound dressings are known to those skilled in the art, as are acrylate adhesives, and are described in more detail, for example, in EP 4218 698 A1. The silicone gel of the wound contact layer has a lower adhesive strength than the acrylate adhesive applied to the backing layer. Accordingly, the adhesive strength of the second adhesive layer is preferably only 1.5 N / 25 mm to 2.7 N / 25 mm. The adhesive strength of the second adhesive layer can be determined according to FINAT No. 1 (FTM 1 Peel adhesion (180°) at 300 mm per minute), although deviations from the standard are permitted in the following points:

[0046] • Bristol paper is used as the substrate instead of glass. The Bristol paper can be, for example, Oxford, plain white paper, non-perforated, reference 237000.

[0047] • The control atmosphere is 20 ± 2 °C, 60 ± 5 % RH or 23 ± 2 °C, 50 ± 5 % RH.

[0048] • Measurements are performed within 20 minutes of sample preparation.

[0049] The thickness of the second adhesive layer can be 80 pm to 200 pm, preferably 100 pm to 150 pm.

[0050] The acrylate adhesive of the wound contact layer (claimed third adhesive layer) can, in terms of its adhesive strength and thickness, be essentially the same as the acrylate adhesive arranged on the backing layer (claimed first adhesive layer). However, the third adhesive layer can also have a different adhesive strength and thickness than the first adhesive layer. The adhesive strength of the third adhesive layer is preferably 2 N / 25 mm to 7 N / 25 mm, in particular approximately 4.5 N / 25 mm. The adhesive strength of the third adhesive layer can be determined according to FINAT No. 1 (FTM 1 Peel adhesion (90°) at 300 mm per minute), although deviations from the standard are possible in the following points: • A steel plate is used as the substrate instead of glass. The steel plate can have dimensions of 50 mm x 150 mm (width x length) and is typically completely flat and smooth.

[0051] • The control atmosphere is 20 ± 2 °C, 60 ± 5 % RH or 23 ± 2 °C, 50 ± 5 % RH.

[0052] • The measurements are carried out immediately after the preparation of the samples.

[0053] The thickness of the third adhesive layer can be between 30 μm and 50 μm. In any case, the adhesive strength and thickness of the third adhesive layer should typically be selected so that the wound contact layer can be permanently attached to the wound pad and, if necessary, also to the backing layer.

[0054] The perforated wound contact layer can have a surface weight of 150 g / m 2 up to 200 g / m 2 70 g / m 2 up to 130 g / m 2 on the silicone gel.

[0055] As already explained, the present dressing is intended in particular for negative pressure wound therapy. It can be advantageous if the dressing also comprises a suction tube for connection to a negative pressure source as part of negative pressure wound therapy. The suction tube preferably has a connector at a wound-side end, which is designed such that the wound-side end of the suction tube can be hermetically fastened to a side of the backing layer facing away from the wound. The connector is generally attached above an opening in the backing layer so that the suction tube can be in fluid communication with the wound cushion of the dressing. Connectors for dressings in negative pressure wound therapy, also called ports, are known to those skilled in the art. One such port is disclosed, for example, in WO 2011 / 076340 A1 or WO 2017 / 097834 A1.Furthermore, the suction hose can advantageously have a connector portion at an end remote from the wound, allowing easy connection to a vacuum source or a secretion collection container. Such a connector with a closure is shown as an example in the left margin of Figure 1a of WO 2017 / 097834 A1.

[0056] In addition, when used in negative pressure wound therapy, it may be useful for the dressing to also include a fluid-impermeable, air-permeable filter. The filter can seal the aforementioned opening in the backing layer in a fluid-tight manner, preventing wound fluid from being sucked out of the dressing. This design is particularly suitable for simple and small negative pressure wound therapy systems in which the wound fluid in the dressing is absorbed by an absorbent layer and the negative pressure source does not have a secretion collection container.

[0057] Depending on the design of the dressing, the filter can be arranged at various locations within the dressing. The filter is preferably connected directly to the backing layer, thereby closing the aforementioned opening in the backing layer. If the dressing includes the previously described connector, the filter can alternatively be arranged within the connector. The filter is preferably a filter membrane.

[0058] Apart from the first and second adhesive layers, the dressing preferably does not comprise any further adhesive layer that comes into contact with a patient's skin or wound surface.

[0059] As already explained at the beginning, the dressing is specifically designed or constructed to be used for wound treatment without a separately provided adhesive strip for attaching and / or sealing the dressing to a patient's body. This refers to adhesive strips designed to be attached to a patient's skin surface and a non-wound side of the backing layer. Typically, such adhesive strips consist of a plastic film with an adhesive coating on one side and, optionally, a release liner as an application system.

[0060] Particularly preferably, the dressing is intended or designed to be used for wound treatment without a separately provided means for securing and / or sealing the dressing to a patient's body. Any additional securing and sealing means are thus excluded from use in conjunction with the dressing in this preferred embodiment. For example, in addition to the aforementioned adhesive strips, liquid sealants provided in tubes or the hydrogel strips known from EP 0 782 421 B1, which can be arranged between the skin and the backing layer to compensate for unevenness, would also be excluded.

[0061] According to the invention, the dressing comprises at least the backing layer, the first adhesive layer, the wound pad, and the three-layer, perforated wound contact layer. Further components of the dressing can be the previously described suction tube including the connector and plug-in connector, the filter, and a release liner. Accordingly, the present dressing can consist of the following components: i. the backing layer ii. the first adhesive layer iii. the wound pad iv. the wound contact layer consisting of the perforated carrier film, the second adhesive layer, and the third adhesive layer v. optionally the release liner vi. optionally the filter vii. optionally the suction tube, preferably the suction tube with connector and / or plug-in connector

[0062] The release liner covers the adhesive, wound-facing side of the dressing. It facilitates handling and protects the dressing from contamination during storage. The release liner is removed by the user before the dressing is applied to the wound site. The release liner can be made up of several parts, for example, two parts. Application systems for self-adhesive wound dressings with this type of release liner are common and well known to those skilled in the art.

[0063] The present invention also relates to a kit for negative pressure wound therapy. The kit comprises a dressing as described above and a suction tube for connecting the dressing to a negative pressure source. The suction tube can be provided separately from the dressing in the kit. In this case, the suction tube is not yet attached to the dressing by the manufacturer. In addition, the suction tube in the kit can comprise a connection piece and / or a plug-in connector, as already mentioned. The kit is typically sterile and can further contain, for example, instructions for use. However, the kit preferably does not comprise an adhesive strip provided separately from the dressing for attaching and / or sealing the dressing to a patient's body, in particular no means provided separately from the dressing for attaching and / or sealing the dressing to a patient's body.Here again, only those adhesive strips are meant that are intended to be attached to the skin surface of a patient and to a side of the backing layer facing away from the wound.

[0064] Another object of the present invention is a system for negative pressure wound therapy. The system comprises a dressing as described above, a negative pressure source, and a suction tube for connecting the dressing to the negative pressure source.

[0065] Finally, the invention also relates to a method for wound treatment comprising the steps: i. Providing a dressing, kit, or system as described above. ii. Attaching the dressing to a wound site, wherein preferably no separately provided adhesive strip is used for attaching and / or sealing the dressing, in particular no separately provided means for attaching and / or sealing the dressing, throughout the entire wound treatment.

[0066] In other words, the invention thus also relates to the dressing, the kit or the system as described above for use in the treatment of a wound, in particular for use in the treatment of a wound with negative pressure, wherein over the duration of the entire wound treatment preferably no separately provided adhesive strip is used for securing and / or sealing the dressing, in particular no separately provided means for securing and / or sealing the dressing.

[0067] The dressing can be used in all of its previously described embodiments for the kit, system, and method. The additional features of the dressing in its specific embodiments are therefore also disclosed in connection with the kit, system, and method.

[0068] Figures

[0069] The following schematic figures are intended to explain and illustrate the invention in more detail by way of example. Similar structural elements may be identified by the same reference numerals in the figures. Except in Figures 2 and 5, the assemblies are each shown in a side sectional view.

[0070] Figure 1 shows a first embodiment of a dressing 1 according to the invention. The dressing 1 comprises a backing layer 2. The backing layer 2 is preferably a transparent, liquid-impermeable and water vapor-permeable plastic film, for example made of polyurethane. The backing layer 2 is fully coated on its wound-facing underside with an acrylate adhesive 3. The acrylate adhesive 3 forms the claimed first adhesive layer of the dressing 1. The dressing 1 further comprises a wound pad 4. This consists of a single layer, which is preferably an absorbent layer. The wound pad 4 and the backing layer 2 are bonded together with the acrylate adhesive 3. In addition, the dressing 1 comprises a three-layer, perforated wound contact layer, which, like the adhesive backing layers 2, 3, can be transparent.The wound contact layer consists of a carrier film 5, which is adhesively coated on both sides. On its underside facing the wound, the carrier film 5 is coated with a silicone gel 6 (claimed second adhesive layer). On its upper side facing away from the wound, the carrier film 5 is coated with an acrylate adhesive 7 (claimed third adhesive layer). Using the acrylate adhesive 7, the wound contact layer can be easily attached to the wound pad 4. The perforations in the wound contact layer, not shown in Figure 1, penetrate all layers of the wound contact layer equally. They can, for example, be cut or punched into the wound contact layer. Finally, the dressing 1 also comprises a two-part release film 8 with grip tabs 9, 10. The release film 8 protects the adhesive underside of the dressing 1 and is removed before the dressing 1 is attached to the wound site.

[0071] As shown in Figure 1, the adhesive backing layer 2, 3 projects beyond both the wound pad 4 and the wound contact layer 5, 6, 7, so that the dressing 1 has an adhesive edge 11 (claimed first adhesive edge). The adhesive edge 11 secures the dressing 1 to the wound site. The wound contact layer 5, 6, 7 and the wound pad 4 are of equal size in terms of their surface area and are flush at their edges. The central positioning of the composite of the wound pad 4 and the wound contact layer 5, 6, 7 on the adhesive backing layer 2, 3 results in the design typical of an island dressing.

[0072] Figure 2 shows the underside of the dressing 1 from Figure 1 (without the release liner 8). The perforations 12 in the wound contact layer 5, 6, 7 can now be seen. They are arranged at regular intervals across the entire surface of the wound contact layer. The number, size, and shape of the perforations 12 are to be understood as examples. In particular, the perforations 12 can also be round. Due to the inventive combination of strongly adhering acrylate adhesive 3 in the edge region 11 and weakly adhering silicone gel 6 in the central, wound-contacting region, the dressing 1 can, on the one hand, adhere firmly to the wound site and, on the other hand, be removed from the wound site again without damaging the wound surface. Figure 3 shows a second embodiment of a dressing 13 according to the invention. The dressing 13 is constructed similarly to the dressing 1 from Figures 1 and 2.In contrast to the variant shown above, however, the dressing 13 has an opening 14 in the adhesive backing layer 2, 3. A suction hose 15 with a connector 16 is attached to the non-adhesive, wound-remote outer or upper side of the backing layer 2 directly above the opening 14. In the illustrated case, the connector 16 comprises a hollow, dome-shaped housing 17 with an adhesively formed flange 18, with which it can be attached to the backing layer 2 in an airtight and liquid-tight manner. The suction hose 15 is in turn attached to the housing 17 in a fluid-conducting manner. The suction hose 15, together with the connector 16, typically consists predominantly of a substantially transparent, flexible plastic, for example, silicone or polyvinyl chloride (PVC). The suction hose 15 can be used to connect the dressing 13 to a vacuum source (not shown) and then subject it to negative pressure.

[0073] In the wound pad 4, the dressing 13 can advantageously be a pressure-distributing layer instead of an absorbent layer, as already explained above. The dressing 13 can also have a release liner to protect its adhesive underside. However, for simplicity, the release liner has been omitted in this figure and also in the subsequent figures.

[0074] Figure 4 shows a third embodiment of the invention as a dressing 19. The dressing 19 differs from the dressing 1 of Figures 1 and 2 in that the wound contact layer 5, 6, 7 projects beyond the wound pad 4. The wound contact layer 5, 6, 7 thus has an adhesive edge 20 (second adhesive edge according to the claim), which is at least partially connected to the adhesive backing layer 2, 3. The adhesive backing layer 2, 3 and the wound contact layer 5, 6, 7 then form a pocket 21 for receiving the wound pad 4. In this embodiment, the wound pad 4 can be particularly well secured in the dressing. The dressing 19, viewed from its underside, is shown in Figure 5.

[0075] Figure 6 shows a fourth embodiment of a dressing 22 according to the invention. The dressing 22 is based on the dressing 19 from Figures 4 and 5. However, it also has the opening 14 already known from Figure 3 and the suction tube with connector 15, 16 so that the dressing 22 can be used for negative pressure wound therapy. Figure 7 shows a fifth embodiment of a dressing according to the invention with the reference numeral 23. The dressing 23 is also based on the dressing 19 from Figures 4 and 5. Unlike before, however, the wound pad 4 here has a multi-layer structure, namely two layers. For example, the upper layer of the wound pad 4, adjacent to the adhesive backing layer 2, 3, could be an absorbent layer. The lower layer, adjacent to the wound contact layer 5, 6, 7, could be a fluid-distributing layer.With this structure, the absorption capacity of the absorbent layer can be better utilized, since the fluid-distributing layer can distribute the wound exudate passing through the wound contact layer 5, 6, 7 over the entire surface of the absorbent layer.

[0076] Finally, Figure 8 shows a sixth embodiment of a dressing 24 according to the invention. This corresponds to the previously described variant of Figure 7, with the exception that the wound pad 4 consists of three layers. It would be advantageous, for example, if the middle layer of the wound pad was an absorbent layer and the two outer layers of the wound pad 4 were fluid-distributing layers. The absorbent layer is then accommodated between the two fluid-distributing layers in the wound pad 4. This leads to an even better distribution of the wound exudate in the wound pad 4.

[0077] The dressings shown in Figures 1 to 8 are all rectangular in shape. However, the dressings can also be round, oval, or heart-shaped. The heart-shaped design can be suitable, for example, for the treatment of wounds in the sacral region. Likewise, it is intended that the dressings according to the invention be made available not only in different shapes but also in different sizes. Dressings in different shapes and sizes are common practice in wound care, so that a suitable dressing is available and can be selected for every wound, regardless of location on the patient's body and regardless of its size.

Claims

Patent claims 1. Dressing (1, 13, 19, 22, 23, 24) for wound treatment, comprising - a backing layer (2), - a first adhesive layer (3) which is arranged on a wound-facing side of the backing layer (2), - a wound pad (4), - a wound contact layer (5, 6, 7), wherein the wound pad (4) is arranged between the backing layer (2) and the wound contact layer (5, 6, 7), and wherein the backing layer (2) with the first adhesive layer (3) projects beyond both the wound pad (4) and the wound contact layer (5, 6, 7), so that the dressing has a first adhesive edge (11) consisting of the backing layer (2) and the first adhesive layer (3), characterized in that - the first adhesive layer (3) consists of an acrylate adhesive and - the wound contact layer consists of a perforated carrier film (5), a second adhesive layer (6) and a third adhesive layer (7), wherein the second adhesive layer (6) is arranged on a side of the carrier film (5) facing the wound and consists of a silicone gel, and wherein the third adhesive layer (7) is arranged on a side of the carrier film (5) facing away from the wound and consists of an acrylate adhesive.

2. Dressing according to claim 1, characterized in that the backing layer (2) has an opening (14) for sucking out air in the context of negative pressure wound therapy.

3. Dressing according to claim 1 or 2, characterized in that the adhesive strength of the first adhesive layer (3) is more than 2.8 N / 25 mm, preferably more than 3.5 N / 25 mm, and particularly preferably more than 4 N / 25 mm.

4. Dressing according to one of the preceding claims, characterized in that the wound pad (4) comprises one or more layers selected from the group consisting of an absorbent layer, a pressure-distributing layer and a fluid-distributing layer.

5. A dressing according to claim 4, characterized in that the absorbent layer consists of a hydrophilic nonwoven fabric or a hydrophilic foam.

6. A dressing according to claim 5, characterized in that the hydrophilic nonwoven fabric comprises alginate fibers, cellulose-based fibers and / or a superabsorbent polymer in the form of fibers.

7. Bandage according to one of claims 4 to 6, characterized in that - the absorbent layer consists of a hydrophilic nonwoven fabric, wherein the nonwoven fabric comprises cellulose-based fibers, in particular cellulose fibers or viscose fibers, and polyacrylate fibers, or - the absorbent layer consists of a hydrophilic, open-cell foam made of polyvinyl alcohol or polyurethane.

8. A dressing according to any one of claims 4 to 7, characterized in that the absorbent layer has an absorption capacity of 50 g / 100 cm 2 until 300 g / 100 cm 2 , preferably 50 g / 100 cm 2 up to 250 g / 100 cm 2 , more preferably 100 g / 100 cm 2 up to 250 g / 100 cm 2 and particularly preferably 140 g / 100 cm 2 up to 220 g / 100 cm 2 has.

9. A dressing according to any one of claims 4 to 8, characterized in that the pressure-distributing layer consists of a spacer fabric, a woven fabric, a 3D-structured plastic film or a hydrophobic, open-cell foam.

10. A dressing according to any one of claims 4 to 9, characterized in that the pressure-distributing layer has an air permeability of 1000 l / (m 2 sec) to 8500 l / (m 2 sec), preferably 1500 l / (m 2 sec) to 6000 l / (m 2 sec), more preferably 2000 l / (m 2 sec) to 5000 l / (m 2 sec), particularly preferably 2300 l / (m 2 sec) to 4000 l / (m 2 sec) and especially of 2400 l / (m 2 sec) to 3300 l / (m 2 sec).

11. A dressing according to any one of claims 4 to 10, characterized in that the fluid-distributing layer consists of a hydrophilic nonwoven fabric, wherein the hydrophilic nonwoven fabric preferably comprises cellulose-based fibers, in particular cellulose fibers or viscose fibers.

12. A dressing according to any one of claims 4 to 11, characterized in that the fluid-distributing layer does not comprise a superabsorbent polymer and / or has a lower absorption capacity than the absorbent layer.

13. A dressing according to any one of claims 4 to 12, characterized in that the fluid-distributing layer has an absorption capacity of 1 g / 100 cm 2 until 50 g / 100 cm 2 , preferably 1 g / 100 cm 2 up to 40 g / 100 cm 2 , more preferably 1 g / 100 cm 2 up to 25 g / 100 cm 2 , particularly preferably 1 g / 100 cm 2 up to 10 g / 100 cm 2 and in particular of 1 g / 100 cm 2 up to 7 g / 100 cm 2 has.

14. A dressing according to any one of claims 4 to 10, characterized in that the wound pad (4) consists of an absorbent layer or a pressure-distributing layer.

15. A dressing according to any one of claims 4 to 13, characterized in that the wound pad (4) consists of an absorbent layer and either a pressure-distributing layer or a fluid-distributing layer, wherein the wound pad (4) is arranged in the dressing in such a way that either - the absorbent layer is adjacent to the wound contact layer (5, 6, 7) and the pressure-distributing or fluid-distributing layer is adjacent to the backing layer (2) or - the absorbent layer is adjacent to the backing layer (2) and the pressure-distributing or fluid-distributing layer is adjacent to the wound contact layer (5, 6, 7).

16. A dressing according to any one of claims 4 to 13, characterized in that the wound pad (4) consists of an absorbent layer and either two pressure-distributing layers or two fluid-distributing layers, the absorbent layer being arranged between the two pressure-distributing or fluid-distributing layers.

17. Dressing according to one of the preceding claims, characterized in that the wound contact layer (5, 6, 7) and the wound pad (4) are of substantially the same size and are substantially flush, or - the wound contact layer (5, 6, 7) projects beyond the wound pad (4), so that the wound contact layer (5, 6, 7) has a second adhesive edge (20), wherein the second adhesive edge (20) is at least partially connected to the backing layer (2), so that the backing layer (2) and the wound contact layer (5, 6, 7) can form a pocket (21) for receiving the wound pad (4).

18. A dressing according to any one of the preceding claims, characterized in that the wound contact layer (5, 6, 7) forms 30% to 90%, preferably 30% to 80%, more preferably 30% to 70% and particularly preferably 50% to 70% of a wound-facing side of the dressing.

19. A dressing according to any one of the preceding claims, characterized in that the adhesive strength of the second adhesive layer (6) is 1.5 N / 25 mm to 2.7 N / 25 mm.

20. A dressing according to any one of the preceding claims, characterized in that the dressing does not comprise any further adhesive layer which comes into contact with a skin or wound surface of a patient, apart from the first and second adhesive layers (3, 6).

21. A dressing according to any one of the preceding claims, characterized in that the dressing is intended to be used for wound treatment without a separately provided adhesive strip for securing and / or sealing the dressing to the body of a patient, in particular without a separately provided means for securing and / or sealing the dressing to the body of a patient.

22. Kit for negative pressure wound therapy, comprising - a dressing according to one of the preceding claims, - a suction hose (15) for connecting the dressing to a vacuum source, and - optionally, instructions for use, wherein the kit preferably does not comprise an adhesive strip for attaching and / or sealing the dressing to a patient's body, in particular no means for attaching and / or sealing the dressing to a patient's body.

23. System for negative pressure wound therapy, comprising - a dressing according to one of claims 1 to 21, - a negative pressure source, and - a suction hose (15) for connecting the dressing to the vacuum source.

24. A dressing, kit or system according to any one of the preceding claims for use in the treatment of a wound, wherein preferably no separately provided adhesive strip is used for securing and / or sealing the dressing, in particular no separately provided means for securing and / or sealing the dressing, throughout the entire wound treatment.

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