WO2021089637A1

WO2021089637A1 - Wound contact layer testing apparatus and method

Info

Publication number: WO2021089637A1
Application number: PCT/EP2020/080989
Authority: WO
Inventors: Latifa GIAFFAR; Paul Gunning; Victoria Jody HAMMOND
Original assignee: T.J. Smith And Nephew, Limited
Priority date: 2019-11-06
Filing date: 2020-11-04
Publication date: 2021-05-14
Also published as: GB201916148D0

Abstract

Disclosed embodiments relate to a wound contact layer testing apparatus. The wound contact layer testing apparatus may be constructed with a circular wall supported by legs, and be configured to deliver negative pressure and/or irrigation to the wound contact layer. The testing apparatus may be constructed from a material that allows for ease of visibility via computed tomography, but which does not attenuate X-rays. The wound contact layer may be configured to deliver iodine.

Description

WOUND CONTACT LAYER TESTING APPARATUS AND METHOD

BACKGROUND

Technical Field

[0001] The application discloses materials, devices, methods and systems, for testing wound contact layers and/or wound dressings.

Description of the Related Art

[0002] Molecular iodine is active against bacteria, fungi and viruses, rapidly penetrating microorganisms, damaging proteins, nucleotides and fatty acids, leading to cell death. Consequently, iodine has been incorporated into numerous patient products, for example Iodosorb Cadexomer Iodine gel by Smith & Nephew. Increasingly there is a need for improved mechanisms of delivering an effective dose of iodine or other antimicrobials to a wound. Of particular interest are mechanisms of delivering iodine in combination with use of a wound contact layer as part of a wound dressing, particularly a negative pressure wound dressing and/or while under negative pressure wound therapy. However, existing methods for testing such wound contact layers may be inadequate to properly simulate a wound due to limitations in the wound model, for example limitations in the ability to properly image the wound testing model in a computed tomography (CT) scanner while under negative pressure and/or irrigation. Therefore, improved methods and techniques for testing wound contact layers and dressings are needed.

SUMMARY

[0003] Embodiments of the present disclosure relate to materials, devices, methods, and systems for wound treatment. Some disclosed embodiments relate to materials, devices, methods, and systems for delivering iodine or other antimicrobials to a wound. It will be understood by one of skill in the art that application of the materials, devices, methods, and systems described herein are not limited to a particular tissue or a particular injury.

[0004] Some of the embodiments described herein provide a therapeutic composition. The therapeutic composition may comprise an elastomeric rubber and a plurality of fluid-absorbent particles. The fluid-absorbent particles may comprise a crosslinked polymer and a therapeutic agent. The fluid-absorbent particles can be configured to swell upon contact with fluid. The therapeutic composition may further comprise a hydrophilic polymer. Alternative or additional embodiments described herein provide a wound contact layer comprising one or more of the features of the foregoing description or of any description elsewhere herein. Alternative or additional embodiments described herein provide a wound dressing comprising one or more of the features of the foregoing description or of any description elsewhere herein.

[0005] In some embodiments, a testing apparatus may comprise a circular wall surrounding a base, the base comprising a plurality of openings, the plurality of openings comprising a negative pressure opening configured to connect to a source of negative pressure; a plurality of legs extending from the wall; a wound contact layer positioned over the openings; and wherein the wall, base, and legs may be constructed from a high density polymer, the high density polymer configured to be readily visible in a computed tomography scan and provide minimal attenuation of X-rays passing therethrough. The high density polymer may be selected from the group consisting of high density polyethylene, high density polypropylene, high density polystyrene, and high density polyester. The high density polymer may be high density polyethylene. The wall, base, and legs may be coated in a conductive layer, the conductive layer comprising an electrically conductive material. The electrically conductive material may be graphite. The conductive layer may be configured to deliver heat to the wound contact layer. The plurality of openings may comprise an irrigation opening, the irrigation opening configured to connect to an irrigant source.

[0006] In certain embodiments, the plurality of openings may comprise a sensing opening, the sensing opening connected to a sensor configured to measure a parameter within the testing apparatus. The sensor may comprise a sensor selected from the group consisting of a pressure sensor, a flow sensor, a temperature sensor, a pH sensor, and a humidity sensor. The plurality of openings may comprise a gas delivery opening, the gas delivery opening connected to a source of therapeutic gas. The testing apparatus may be configured to be sealed such that negative pressure may be delivered to the wound contact layer. The testing apparatus may include a lid configured to be placed over the circular wall and seal the testing apparatus such that negative pressure may be delivered to the wound contact layer. The testing apparatus may further include a cover layer configured to overlie and seal the testing apparatus such that negative pressure may be delivered to the wound contact layer. The plurality of legs may comprise four legs. The testing apparatus may be configured to control the source of negative pressure and the instillation source such that negative pressure and irrigation may be delivered to the wound contact layer in alternating fashion. The testing apparatus may be configured to control the source of negative pressure and the instillation source such that negative pressure and irrigation may be delivered simultaneously to the wound contact layer. The wound contact layer may comprise iodine. The testing apparatus may comprise or more features described herein. The testing apparatus may be used via a method comprising one or more features described herein.

[0007] In embodiments, testing apparatus may comprise a circular wall surrounding a base, the base comprising a plurality of openings configured to connect to a source of negative pressure; a plurality of legs extending from the wall; a wound contact layer positioned over the openings; and wherein the base, wall, and legs are constructed from a high density polyethylene.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIGS. 1 A-l C show embodiments of a multi-care wound contact layer (“WCL”) in the form of a square-perforated layer, all comprising (by weight) 45% silicone, 5% PEG, and 50% Cadexomer Iodine; FIG. 1 A is a photograph of an embodiment of a multi-care WCL having perforations in the shape of a truncated square pyramid; FIG. IB is a photograph of an embodiment of a multi-care WCL having perforations in the shape of a square-base cube; and FIG. 1 C shows a three-dimensional finite element simulation model for an embodiment of a multi-care WCL in the form of a square-perforated layer;

[0009] FIGS. 1D-1E show embodiments of a multi-care WCL in the form of a circle- perforated layer, both comprising (by weight) 45% silicone, 5% PEG, and 50% Cadexomer Iodine; FIG. ID is a photograph showing an embodiment of a multi-care WCL in the form of a circle- perforated layer, where the circle perforations are packed into triangles; FIG. IE illustrates two representative layouts of the circle perforations: square packing and triangular packing;

[0010] FIGS. 1F-1G show embodiments of a multi-care WCL in the form of a hexagonal-perforated layer, both comprising (by weight) 45% silicone, 5% PEG, and 50% Cadexomer Iodine; FIG. IF is a photograph showing an embodiment of a multi-care WCL in the form of a hexagonal-perforated layer; and FIG. 1G illustrates a representative layout of the hexagonal perforations;

[0011] FIG. 2 illustrate photographs of an embodiment of a multi-care WCL in a form of a square-perforated layer during wound model testing; [0012] FIG. 3 is a schematic diagram of an example of a negative pressure wound therapy system;

[0013] FIG. 4A illustrates an embodiment of a negative pressure wound treatment system employing a pump, a flexible fluidic connector and a wound dressing capable of absorbing and storing wound exudate;

[0014] FIG. 4B illustrates an embodiment of a negative pressure wound treatment system employing a flexible fluidic connector and a wound dressing capable of absorbing and storing wound exudate;

[0015] FIG. 4C illustrates a cross section of an embodiment of a fluidic connector connected to a wound dressing;

[0016] FIGS. 5A-5C illustrates a perspective, top view, and side view of an embodiment of a wound model for testing a wound contact layer;

[0017] FIG. 5D is a photograph of an embodiment of a wound model for testing a wound contact layer;

[0018] FIGS. 6A-6F are computer reconstructed images of an embodiment of a wound model for testing a wound contact layer; and

[0019] FIG. 7 illustrates an embodiment of a wound model for testing a wound contact layer.

DETAILED DESCRIPTION

Overview

[0020] Embodiments described herein relate to materials, apparatuses, methods, and systems that incorporate, or comprise, or utilize a wound contact layer (“WCL”) for positioning in contact with a wound. A WCL may be utilized as a stand-alone component for separately positioning at a wound site, or may be incorporated into any number of multi-layer wound dressings and wound treatment apparatuses, such as described herein below with respect to the figures. Embodiments of the present disclosure are generally applicable to use under ambient conditions, in negative pressure or reduced pressure therapy systems, or in compression therapy systems. Some of the preferred embodiments described herein incorporate, or comprise, or utilize multi-care wound contact layers. Such a multi-care WCL possesses two or more of the following functional features: antimicrobial activities, easiness to apply or/and remove as one piece, easiness to cut with scissors, conformability to the three-dimensional contour of a wound surface, durability to wear, compatibility with negative pressure wound therapy or/and compression wound therapy, exudate management, capability of facilitating autolytic debridement of wound, capability of promoting wound healing, and self-indication of compositional or functional changes. The antimicrobial activities, such as in vitro antimicrobial activities, can include one or more of the following: broad-spectrum antimicrobial activity, anti-biofdm activity, rapid speed of kill against microorganisms, sustained kill against microorganisms; and the microorganisms can include one or more of the following: Gram-negative bacteria, Gram -positive bacteria, fungi, yeasts, viruses, algae, archaea and protozoa.

[0021] Certain preferred embodiments described herein provide a wound treatment system. Such a wound treatment system may comprise a stand-alone layer of multi-care WCL, configured to be sized for positioning over a wound. The wound treatment system may further comprise a secondary wound dressing configured to be separately positioned over the multi-care WCL. The multi-care WCL may have an adhesive adhered to the lower surface; and the adhesive can be configured that the multi-care WCL will be placed in proximity to the wound. The secondary wound dressing, if used, may adhere to skin surrounding the wound and may have the same size or may be larger than the multi-care WCL, so that the multi-care WCL will touch or be placed in proximity to the wound. The secondary wound dressing can be alternatively or additionally configured to form a seal to skin surrounding the wound so that the multi-care WCL will touch or be placed in proximity to the wound. The wound treatment system may further comprise a source of negative pressure configured to supply negative pressure through the secondary wound dressing and through the multi-care wound contact layer to the wound.

[0022] Certain other preferred embodiments described herein provide a multi-layered wound dressing, such as described herein the specification with respect to the figures. Such a multi layered wound dressing may incorporate a multi-care WCL as a component layer thereof or, alternatively, may comprise a composite or laminate including the multi-care WCL as part of one of the component layers thereof. The multi-layered wound dressing may comprise: a multi-care wound contact layer as described above or described elsewhere herein; a transmission layer and/or absorbent layer over the multi-care wound contact layer; and a cover layer over the transmission layer and/or absorbent layer. The wound dressing may further comprise an adhesive layer on the lower surface of the multi-care wound contact layer. The wound dressing may further comprise a negative pressure port positioned on or above the cover layer. The multi-care wound contact layer may have a perimeter shape that is substantially the same as a perimeter shape of the cover layer. Alternatively, the multi-care wound contact layer may have a perimeter shape that is smaller than a perimeter shape of the cover layer. One of skill in the art will understand that therapeutic agents, such as any disclosed herein this “Overview” section or elsewhere in the specification, may be loaded within the multi-care WCLs in powder form. One of skill in the art will further understand that therapeutics, such as any disclosed herein this section or elsewhere in the specification, in powder form may be incorporated into any suitable absorbent layer disclosed herein this section or elsewhere in the specification, and/or any suitable transmission layer disclosed herein this section or elsewhere in the specification, and/or any foam layer disclosed herein this section or elsewhere in the specification.

[0023] In certain further preferred embodiments, the wound treatment systems and multi-layered wound dressings disclosed above or disclosed elsewhere herein the specification may incorporate or comprise an antimicrobial delivering multi-care wound contact layer. The antimicrobial species may be iodine, silver ions, or another suitable species. For example, such multi-care WCLs may deliver an iodine-containing compound such as incorporated into Iodosorb by Smith & Nephew. As described herein this section or elsewhere in the specification, particularly below, the multi-care WCL may be configured to be activated to release antimicrobial species, such as iodine-containing molecules, by contact with moist or aqueous medium, such as wound exudate. Upon contact with moist or aqueous medium, either provided by wound exudate or not, the multi-care WCL layer may release antimicrobial species. At least a portion of the released antimicrobial species may be released, for example by diffusion. To facilitate release and diffusion of antimicrobial species, the multi-care WCL may be placed proximate to the wound to enable absorption of exudate.

[0024] Some preferred embodiments described herein the specification provide a method to treat a wound or locus. Such a method may include placing a multi-care WCL, either separately or by placing a multi-layered wound dressing having a multi-care WCL, over the wound. The method may comprise adhering the separate multi-care WCL and/or the multi-layer wound dressing having a multi-care WCL to healthy skin around the wound. The method may further comprise one or more of the following steps: A further wound dressing can be placed over the separate multi-care WCL or multi-layered wound dressing having the multi-care WCL that is placed over the wound. Wound exudate, or any moist or aqueous medium other than wound exudate, may be provided to reach and/or touch the multi-care WCL. Wound exudate, or any moist or aqueous medium other than wound exudate may be diffused or wicked into the wound dressing incorporating the multi-care WCL or into a wound dressing provided over the multi-care WCL. Negative pressure may be applied to the separate multi-care WCL or multi-layered wound dressing having the multi-care WCL, such that wound exudate is suctioned into the multi-care WCL directly, or into the wound dressing incorporating the multi-care WCL, or into a wound dressing provided over the multi-care WCL.

Therapeutic Composition

[0025] Some of the embodiments disclosed herein provide a therapeutic composition. The therapeutic composition may comprise one or more matrix polymers and a plurality of fluid- absorbent particles. The one or more matrix polymers may form a matrix in which the plurality of fluid-absorbent particles may be embedded.

[0026] The fluid-absorbent particles may be configured to swell upon contact with fluid as disclosed later in the specification. The fluid-absorbent particles that are configured to swell upon contact with fluid may absorb exudate from a wound, for example, when materials made from the therapeutic composition are placed in proximate to the wound. The fluid-absorbent particles that are configured to swell upon contact with fluid may comprise superabsorbent particles such as any disclosed herein this “Therapeutic Composition” section or elsewhere in the specification. In some embodiments, the fluid-absorbent particles may comprise spherical beads, non-spherical beads, or a mixture thereof. In some embodiments, the fluid-absorbent particles may comprise a diameter of less than 1 mm, preferably between 100 and 800 pm.

[0027] The fluid-absorbent particles may each comprise one or more therapeutic agents. The one or more therapeutic agents may comprise one or more of the following: antimicrobial agent, antibiotic drug, antiviral agent, anti-inflammatory agent, anti-histamine agent, local anesthetic, wound healing agent, vitamin, or mixtures thereof. One of skill in the art will understand that at least one of the one or more therapeutic agents, such as any disclosed herein this “Therapeutic Composition” section or elsewhere in the specification, may be loaded within the therapeutic compositions in powder form. One of skill in the art will also understand that at least a portion of the one or more therapeutic agents, loaded within the fluid-absorbent particles, may comprise extractable therapeutic agents, and that the extractable therapeutic agents can be released from materials made from the therapeutic composition.

[0028] In some embodiments, a therapeutic composition is disclosed that comprises fluid-absorbent particles that comprise an iodine-based antimicrobial agent. The iodine-based antimicrobial agent may comprise between 0.1% and 5%, or between 1% and 2%, preferably less than 2% by weight within the fluid-absorbent particles. The total antimicrobial iodine, as loaded within the fluid-absorbent particles, may comprise about 50% by weight extractable iodine.

[0029] In some embodiments, a therapeutic composition is disclosed that comprises fluid-absorbent particles that each comprises a crosslinked polymer and a therapeutic agent. The crosslinked polymer may comprise a crosslinked polysaccharide. The therapeutic agent may comprise an iodine-based antimicrobial agent. In some embodiments, the fluid-absorbent particles may comprise between about 30% and about 90%, preferably between about 50% and about 60%, by weight of the therapeutic composition. In some preferable embodiments, the fluid-absorbent particles may comprise between about 50% and about 63% by volume of the therapeutic composition, for example, when the fluid-absorbent particles comprise spherical beads of substantially uniform size.

[0030] In some preferable embodiments, the fluid-absorbent particles may comprise crosslinked polysaccharide beads containing antimicrobial iodine. The crosslinked polysaccharide beads may be selected from a group comprising Cadexomer, Sephadex, Dextranomer, Debrisan, or a mixture thereof. Cadexomer Iodine (iodinated Cadexomer beads) may comprise antimicrobial iodine of less than 2% by weight and, among the antimicrobial iodine, extractable iodine of less than 1% by weight based on the total weight of Cadexomer Iodine. Cadexomer Iodine may comprise about 30-90%, or 50-60% by weight of the therapeutic composition.

[0031] The one or more matrix polymers may comprise an elastomeric rubber. The elastomeric rubber in the matrix may provide the structural integrity that permits materials made from the therapeutic composition to sustain pressures, including below- and/or above-ambient pressures. The elastomeric rubber may also provide the cohesiveness that allows one-piece application and removal of materials made from the therapeutic composition. The cohesiveness provided by the elastomeric rubber may further prevent shedding of the fluid-absorbent particles, for example, when materials made from the therapeutic composition swell or/and experience deformations in use. [0032] The elastomeric rubber may comprise one or more silicones. The one or more silicones may comprise a room temperature vulcanizing (RTV) silicone. The RTV silicone may comprise an addition curing RTV silicone, made from a mixture of at least one rubber base and at least one curing agent. The addition curing RTV silicone may be selected from a group comprising Silpuran silicones, Elastosil silicones, Cenusil silicones, Silmix silicones, or a mixture thereof. One of skill in the art will understand each family of silicones include variations, for example, in molecular weights, mechanical properties or/and other properties. For example, Silpuran silicones may include, but are not limited to, Silpuran 2100, Silpuran 2110, Sipuran 2112, Silpuran 2120, Silpuran 2130, Silpuran 2400, Silpuran 2400/25, Silpuran 2445, Silpuran 2450, Silpuran 4200, Silpuran 6000, Silpuran 6400, Silpuran 6600, Silpuran 6700, Silpuran 8020, Silpuran 8030, Silpuran 8060, Silpuran 8461, and Silpuran 8630. For another example, Silpuran 2400/25 is softer than Silpuran 2400. According to the manufacturer’s website, the Shore A hardness, determined according to ISO 868 standards, of Silpuran 2400 is 7 (https://www.wacker.com/cms/en/products/product/product.jsp?product=13693), while the Shore A hardness of Silpuran 2400/25 is below 0

(https : //www. wacker. com/ cms/ en/products/product/product.j sp?product=l 3950).

[0033] In some embodiments, the weight % of elastomeric rubber within the therapeutic composition, or materials made from the therapeutic composition, may be between about 10% to about 90%, preferably between about 30% to about 70%.

[0034] The one or more matrix polymers, comprising an elastomeric rubber, may further comprise a hydrophilic polymer. The ratios between the matrix polymers can be configured to form a flexible layer capable of conforming to the wound surface, and to provide a soft tactile feel. The hydrophilic polymer may be configured to form a hydrophilic phase in the matrix. The hydrophilic phase may provide a pathway for fluid ingress to reach the fluid-absorbent particles encapsulated or embedded in the matrix. As such, in embodiments, the hydrophilic phase of the matrix can dictate the onset and dynamics of the therapeutic release.

[0035] The hydrophilic polymer may comprise one or more polyethylene glycols (PEGs). The one or more PEGs may comprise an average molecular weight of about 100 g/mol to about 40,000 g/mol. One of skill in the art will understand that the average molecular weight (g/mole or Da) of a PEG may be denoted as a number in the name of PEG. For example, PEG-400 refers to a PEG having an average molecular weight of approximately 400 g/mole (or Da). The one or more PEGs may be selected from a group comprising: PEG- 100, PEG-200, PEG-400, PEG- 600, PEG- 1000, PEG-3000, PEG-4000, PEG- 10000, PEG-35000, or a mixture thereof.

[0036] In some embodiments, the weight % of hydrophilic polymer within the therapeutic composition, or materials made from the therapeutic composition, may be about 30% or less, preferably, about 20% or less. For example, the PEG may comprise about 20%, 15%, 10%, 5%, or 1% of the therapeutic composition.

[0037] The elastomeric rubber and/or the hydrophilic polymer may comprise biocompatible polymers that are suitable for contacting a wound. In some embodiments, at least one of the one or more matrix polymers may be already approved by the FDA for use in wound care. Exemplary biocompatible hydrophilic polymers may comprise PEGs such as PEG-400. Exemplary biocompatible elastomeric rubbers may include Silpuran silicones and Elastosil silicones, such as Silpuran 2400 and Silpuran 2400/25. Certain preferable embodiments of therapeutic compositions may comprise Silpuran silicones for their FDA-approved use in broken skin.

[0038] Some of the embodiments described herein provide materials, particularly wound care materials, made from and/or comprises a therapeutic composition as described above or described elsewhere herein the specification.

[0039] Some of the embodiments described herein provide a wound contact layer that is made from and/or comprises a therapeutic composition as described above or described elsewhere herein the specification.

[0040] Some of the embodiments described herein provide a wound dressing. The wound dressing comprises a layer that is made from and/or comprises a therapeutic composition as described above or described elsewhere herein the specification.

Multi-Care Wound Contact Laver

[0041] Some of the embodiments described herein provide a multi-care wound contact layer. The multi-care wound contact layer may comprise a flexible, biocompatible layer. The flexible, biocompatible layer may comprise a therapeutic composition as described above or described elsewhere herein the specification. In some embodiments, the flexible, biocompatible layer may comprise by weight: 10-90%, preferably 30-70% elastomeric rubber; 1 -20% hydrophilic polymer; and 30-90%, preferably 50-60% fluid-absorbent particles. Table 1 illustrates eight representative compositions of the multi-care WCL: Examples 1 and 5 comprise silicone and Cadexomer Iodine, while Examples 2-4 and 6-8 further comprise PEG-400.

Table 1. Benchmark compositions of multi-care WCLs

[0042] Figures 1A-1G show preferable embodiments of a multi-care WCL that comprises a flexible, biocompatible layer, but this application is not limited to these preferable embodiments. As shown in Figure 12A, a flexible, biocompatible layer of a multi-care WCL 2500 may comprise an upper surface 2530, a lower surface 2540, and four side surfaces 2550. Although the illustrated embodiments have four side surfaces to form a rectangular or square shape, the multi-care WCL may have other shapes as well, such as multi-sided polygon, circular, elliptical, multi-lobe, and any of the shapes depicted and described for the wound dressing layers described herein. The shape of a multi-care WCL may comprise sharp corners, such as squared comers, or rounded corners, or a combinations thereof. The upper and lower surfaces may define a thickness 2555 therebetween.

[0043] The flexible, biocompatible layer may further comprise an array of perforations (or holes) extending partially or entirely through the thickness. The perforations may comprise a three-dimensional (3D) shape selected from the group comprising: sphere, cone, cylinder, cube, pyramid, and a truncated form thereof. Each perforation 2510 may comprise an opening on the upper surface 2530, or an opening on the lower surface 2540, or both. Any one perforation may comprise identical or different openings on the upper and lower surfaces. The opening may comprise a two dimensional (2D) size 2515 described further below. The flexible, biocompatible layer may comprise a network of internal walls 2520, and the network of internal walls may comprise a wall width 2525 that may define the space between two adjacent perforations. The internal walls 2520 may be parallel to the side surfaces 2550, or may be provided at a non-90 degree angle relative to the side surfaces 2550, or may comprise a combination thereof. For example, as shown in Figure IB, the internal walls may be parallel to the side surfaces, and the openings of the perforations may be identical between the upper and lower surfaces. In other embodiments, the internal walls may be provided at a non-90 degree angle relative to the side surfaces, despite that the openings of the perforations may be identical between the upper and lower surfaces. In yet other embodiments, the two openings of a perforation on the upper and lower surfaces may differ, for example, the perforations may comprise a pyramidal or truncated pyramidal shape (such as shown in Figure 1 A) and, thus, the internal walls 2520 may be provided at an angle relative to the side surfaces 2550 (e.g., at a 45 degree angle). In the embodiments illustrated in Figures 1A-1C, the internal walls also form a grid of parallel rows and columns of perforations, where the rows are perpendicular to the columns.

[0044] The opening of a perforation on the upper or lower surface may comprise a 2D shape selected from the group comprising: a circle (such as in Figure ID), an oval, a triangle, a square (such as in Figures 1A-1B), a rectangle, a hexagon (such as in Figure IF), an octagon or any other polygon or shape. One of skill in the art will understand that the size of the opening may be defined depending on the shape of the opening. In some embodiments, the size of a circle is the diameter. In other embodiments, the size of an oval is the longer diameter. In yet other embodiments, the size of a hexagon is the longest diagonal; and the size of a triangle, a square, a rectangle, an octagon or any other polygon perforation is the longest side. When the two openings of a perforation on the upper and lower surfaces are identical, the 2D shape of an opening may be referred to as the shape of a perforation, and the 2D size of an opening may be referred to as the size of a perforation. The size of the opening or perforations may be at least 0.5 mm, preferably between 0.5 to 3.5 mm, or between 1 to 3 mm. The wall width defining the space between two adjacent perforations may be between 0.5 to 5 mm, preferably 0.5 to 3.5 mm, or between 1 to 3 mm.

[0045] One of skill in the art will understand that certain embodiments of the multi care WCL, such as described in the preceding paragraph or described elsewhere herein the specification, may be denoted according to the shape, size and layout of the perforations. For example, Figure 12D shows an embodiment that may be denoted as having a circle geometry with triangle packing. This denotation indicates that the perforations are circular and the circular perforations are arranged in a triangle packed layout, as shown in the right side of Figure IE, wherein adjacent rows of perforations are offset from one another. In one example, the embodiment of Figure ID may have circular perforations having a size (i.e., diameter) of 3 mm, with the space between any two adjacent perforations being 1 mm. Another embodiment may be denoted as having a circle geometry with square packing. A square-packed layout is shown in the left side of Figure 1 E, wherein the all of the perforations are arranged in parallel rows and columns. In such an embodiment, the perforations may have a size (i.e., diameter) of 3 mm, with the space between any two adjacent perforations being 1 mm. Figure IF illustrates an embodiment that may be denoted as having a hexagonal geometry with triangular packing. This denotation indicates that the perforations are hexagonal and the hexagonal perforations are arranged in a triangle packed layout, as shown in Figure 1G.

[0046] The thickness of the multi-care WCL (such as 2555 in Figure 1A) may be selected or pre-determined to achieve a desired loading of therapeutics. One of skill in the art will understand that the total loading of therapeutics may depend on the total mass (or volume) of the multi-care WCL and the amount of therapeutics loaded per unit mass (or volume) of the multi care WCL. One of skill in the art will also understand that the total mass (or volume) of the perforated multi-care WCL can be jointly determined by the perforation size, the wall width that defines the space between two adjacent perforations, and the thickness of the flexible, biocompatible layer. As described above with respect to the therapeutic composition or described elsewhere herein the specification, one of skill in the art will further understand that a desired amount of therapeutics loaded per unit mass (or volume) of the multi-care WCL may be obtained by varying the loading of therapeutics within each fluid-absorbent particles or/and the amount of the fluid-absorbent particles within a unit mass (or volume) of the multi-care WCL. In certain embodiments, the weight % of the antimicrobial iodine within the fluid-absorbent particles may be between 0.1% and 5%, or between 1% and 2%, or preferably less than 2%. In certain embodiments, the weight % of the fluid-absorbent particles within the multi-care WCL may be between about 30% and about 90%, preferably between about 50% and about 60%. In certain embodiments, the volume % of the fluid-absorbent particles within the multi-care WCL may be preferably between about 50% and about 63%, for example, when the fluid-absorbent particles comprise spherical beads of substantially uniform size.

Table 2. Geometries and dimensions of thirteen benchmark embodiments of the multi-care wound contact layer (WCL). All these embodiments comprise, by weight, 45% silicone, 5% PEG, and 50% Cadexomer Iodine; and the Cadexomer Iodine comprises 1.8% of iodine by weight. One of skill in the art will understand that the volumes of these embodiments may vary according to the geometrical parameters of the perforation array.

^ Perforation sizes and wall widths are defined as described above herein this section.

* Square geometries E-H and Circle geometries O-Q comprise the same amount of Cadexomer Iodine per unit area, which is defined as 1.00. The amounts of Cadexomer Iodine per unit area are calculated for the other geometries in relation to this reference amount and summarized in the “Relative amount of Cadexomer Iodine per unit area” column. The unit area refers to the surface area, including the perforated portion, of the lower surface of the multi-care WCL that may contact the wound at least partially. One of skill in the art would understand that the amount of Cadexomer Iodine per unit area may affect the antimicrobial activity of the multi-care WCL. [0047] As illustrated in Table 2, one of skill in the art will understand how to determine a desired thickness of a multi-care WCL based on, for example, the desired dose of therapeutics, the density of therapeutics loaded within the multi-care WCL, and the geometry and size of the perforations. Table 2 summarizes the dimensions of thirteen representative embodiments of a multi-care WCL, including ten square perforation geometries (“A” through “J”), two circle perforation geometries (“O” and “Q”), and one hexagonal perforation geometry (“S”). One of skill in the art will understand that the embodiments of the multi-care WCL are denoted according to the shape, size and layout of the perforations. One of skill in the art will also understand that the volumes of these embodiments may vary according to the geometrical parameters of the perforation array. One of skill in the art will further understand that the wound surface area that needs to be covered by the multi-care WCL may be helpful information for determining the desired thickness, and that the amount of Cadexomer Iodine per unit area may affect the antimicrobial activity of the multi-care WCL.

[0048] In some embodiments, the multi-care WCL may comprise therapeutics, such as any disclosed above with respect to the therapeutic compositions or elsewhere herein the specification, in the matrix other than or in addition to those within the fluid-absorbent particles embedded in the matrix. One of skill in the art will understand that such therapeutics may be loaded within the multi-care wound contact layer in powder form.

[0049] Some embodiments of the multi-care WCL may comprise substantially the same top and bottom surfaces; and either surface may be applied onto the wound surface without the need to distinguish between a wound facing face and a reverse face. Some alternative embodiments of the multi-care WCL may have different opening shapes and/or sizes of perforations between top and bottom surfaces, allowing a distinction between a wound facing face and a reverse face. For example, the perforations may have a constant shape and size from the upper surface 2530 to the lower surface 2540 (such as in Figure IB), or the size may vary between the upper and lower surfaces (such as in Figure 1 A).

[0050] The multi-care WCL described in this “Multi-Care Wound Contact Layer” section or described elsewhere herein the specification may exhibit more than one of the following functional features: The multi-care WCL can be configured to achieve a rapid speed of kill against broad-spectrum micro-organisms, for example, at least in vitro , to rapidly reduce microbial viability within 4 hours after application of the multi-care WCL. The multi-care WCL can be configured to achieve sustained microbial killing, for example, at least in vitro , to produce a four- log reduction or more in microbial counts at day two and maintain this level of activity at day three. The multi-care WCL can be configured to achieve anti-biofilm efficacy, for example, at least in vitro , to reduce biofilm associated cells at day three. The multi-care WCL may be designed to be readily manipulated by a physician, such as easy to cut with scissors, easy to apply, and easy to remove as one piece, followed by wound cleansing to remove fluid-absorbent particles loosened from the matrix material. The multi-care WCL may be conformable to the contour of a wound surface. The multi-care WCL may be compatible with compression wound therapy, for example, capable of maintaining pressure for at least about three days (72 hours) or more and durable to wear. The multi-care WCL may be compatible with negative pressure wound therapy, for example, PICO or RENAS YS for at least about three days or more and durable to wear. The multi-care WCL may be configured to absorb, store, and manage wound exudate. The multi-care WCL may facilitate autolytic debridement of the wound and promote healing. The multi-care WCL may be self-indicating of compositional or functional changes.

[0051] One of skill in the art will understand that desired anti-microbial properties of a multi-care WCL may depend on the dose of therapeutics within the multi-care WCL (e.g., “Relative amount of Cadexomer Iodine per unit area” as shown in Table 2). For example, the antimicrobial efficacy of a multi-care WCL may be improved by increasing the loading density of the fluid-absorbent particles, by increasing the space (wall width) between adjacent perforations, and/or by increasing the thickness of the multi-care WCL. One of skill in the art will thus understand that, with respect to a desired therapeutic dose, increasing the wall width may allow decreasing the thickness of the multi-care WCL.

[0052] As disclosed in the preceding “Therapeutic Composition” section with respect to therapeutic compositions and disclosed elsewhere herein the specification, the hydrophilic phase of the matrix can dictate the onset and dynamics of the therapeutic release. One of skill in the art will thus understand that the speed of kill against microorganisms may be improved by increasing the antimicrobial loading (such as Cadexomer Iodine (%)) or the amount of the hydrophilic polymer (such as PEG (%)). For another example, more sustained antimicrobial activities may be achieved by decreasing the amount (%) of PEG, which slows the ingress of fluid along the matrix and the release of Iodine. [0053] As disclosed in the preceding “Therapeutic Composition” section and disclosed elsewhere herein the specification, fluid-absorbent particles, embedded in the flexible, biocompatible layer, may be configured to swell upon contact with fluid (or exudate). One of skill in the art will understand that increasing the loading density of fluid-absorbent particles may result in greater swelling of a multi-care WCL, particularly when fully saturated with fluid (or exudate). Accordingly, one of skill in the art will understand that increasing the loading density of fluid- absorbent particles may require use of larger perforations or thinner walls between adjacent perforations to allow the passage of negative pressure through the multi-care WCL. Moreover, one of skill in the art will also understand that increasing the perforation size may require increasing the thickness of the multi-care WCL to obtain a desired therapeutic dose; and a thicker layer may block negative pressure wound treatment. One of skill in the art will, thus, understand the potential trade-off between increasing the iodine loading in the multi-care WCL and maintaining the compatibility with negative pressure wound therapy.

[0054] As illustrated in Figure 2, contact with wound fluid (or exudate) may trigger fluid-absorption by the multi-care wound contact layer, and the perforated structure of the multi care WCL swells. As a result, the Cadexomer Iodine begins to release therapeutic agent.

Method of Treating a Wound

[0055] Some preferred embodiments described herein the specification provide a method of treating a wound or locus. The method of treating a wound or locus may comprise positioning a wound contact layer in contact with the wound. The wound contact layer may comprise a flexible, biocompatible layer having an upper surface and a lower surface defining a thickness there between and an array of holes extending at least partially through the thickness. The flexible, biocompatible layer may comprise an elastomeric rubber, and a plurality of fluid- absorbent particles that are embedded in the flexible, biocompatible layer. The flexible, biocompatible layer may preferably further comprise a hydrophilic polymer. The fluid-absorbent particles can be configured to swell upon contact with fluid. Each of the fluid-absorbent particles may comprise a crosslinked polymer and an iodine-based antimicrobial agent, and may release the iodine-based antimicrobial agent upon the plurality of fluid-absorbent particles coming into contact with fluid from the wound. The wound contact layer may comprise a multi-care WCL such as disclosed above or disclosed elsewhere herein the specification, made from a therapeutic composition such as disclosed above or disclosed elsewhere herein the specification.

[0056] A method of treating a wound or locus may further comprise sizing the wound contact layer to a size of the wound before positioning the wound contact layer in contact with the wound. Sizing the wound contact layer may comprise cutting the wound contact layer to match the size of the wound. The wound contact layer can be positioned in contact with the wound with an adhesive adhered to the lower surface of the wound contact layer.

[0057] A method of treating a wound or locus may further comprise, after positioning the wound contact layer in contact with the wound, separately positioning a secondary wound dressing over the wound contact layer and adhering the secondary wound dressing to skin surrounding the wound. Alternatively, the wound contact layer can be integrated into a wound dressing comprising a transmission layer and/or absorbent layer over the multi-care wound contact layer and a cover layer over the transmission layer and/or absorbent layer. The wound contact layer may have a perimeter shape that is substantially the same as or, alternatively, smaller than a perimeter shape of the cover layer.

[0058] Some preferable embodiments described herein the specification provide a method to treat a wound or locus. Such a method may include placing a multi-care WCL, either separately or by placing a multi-layered wound dressing having a multi-care WCL, over the wound. The method may comprise adhering the separate multi-care WCL and/or the multi-layer wound dressing having a multi-care WCL to healthy skin around the wound. The method may further comprise one or more of the following steps: A further wound dressing can be placed over the separate multi-care WCL or multi-layered wound dressing having the multi-care WCL that is placed over the wound. Wound exudate, or any moist or aqueous medium other than wound exudate, may be provided to reach and/or touch the multi-care WCL. Wound exudate, or any moist or aqueous medium other than wound exudate may be diffused or wicked into the wound dressing incorporating the multi-care WCL or into a wound dressing provided over the multi-care WCL. Negative pressure may be applied to the separate multi-care WCL or multi-layered wound dressing having the multi-care WCL, as described in the following “Negative Pressure Wound Therapy (NPWT) Systems” section or described elsewhere herein the specification, such that wound exudate is suctioned into the multi-care WCL directly, or into the wound dressing incorporating the multi-care WCL, or into a wound dressing provided over the multi-care WCL. [0059] The method of treating a wound or locus as described above or described elsewhere herein may further comprise delivering negative pressure through the wound contact layer to the wound, as described in the following “Negative Pressure Wound Therapy (NPWT) Systems” section or described elsewhere herein the specification. The wound contact layer may substantially maintain the negative pressure delivered for at least about 24 hours, or for at least about 48 hours, or preferably for at least about 72 hours. Alternatively, the method of treating a wound or locus may comprise applying compression (positive) pressure through the wound contact layer to the wound. Alternatively, the method of treating a wound or locus may comprise altering ambient pressure, negative pressure and compression pressure in a programmable manner through the wound contact layer to the wound.

[0060] In some alternative embodiments, the method of treating a wound or locus may comprise using the wound contact layer, or the wound treatment system or wound dressing that comprises the wound contact layer, under ambient conditions not in connection with a negative pressure wound therapy system as described above, or described elsewhere herein.

[0061] In some embodiments, a method of treating a wound or locus may reduce the wound bioburden, for example, at least in vitro , by reducing the numbers (CFU/mL) of viable microorganisms within the first 4 hours after the application wound contact layer, or by four log or more after 48 through 72 hours after positioning the wound contact layer in contact with the microorganisms.

Negative Pressure Wound Therapy (NPWT) Systems

[0062] It will be understood that embodiments of the present disclosure are generally applicable to, but not limited to, use in topical negative pressure (“TNP”) therapy systems. Briefly, negative pressure wound therapy assists in the closure and healing of many forms of “hard to heal” wounds by reducing tissue oedema; encouraging blood flow and granular tissue formation; removing excess exudate and may reduce bacterial load (and thus infection risk). In addition, the therapy allows for less disturbance of a wound leading to more rapid healing. TNP therapy systems may also assist on the healing of surgically closed wounds by removing fluid and by helping to stabilize the tissue in the apposed position of closure. A further beneficial use of TNP therapy can be found in grafts and flaps where removal of excess fluid is important and close proximity of the graft to tissue is required in order to ensure tissue viability. [0063] As is used herein, reduced or negative pressure levels, such as -X mmHg, represent pressure levels relative to normal ambient atmospheric pressure, which can correspond to 760 mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Accordingly, a negative pressure value of -X mmHg reflects absolute pressure that is X mmHg below 760 mmHg or, in other words, an absolute pressure of (760-X) mmHg. In addition, negative pressure that is “less” or “smaller” than X mmHg corresponds to pressure that is closer to atmospheric pressure (e.g., - 40 mmHg is less than -60 mmHg). Negative pressure that is “more” or “greater” than -X mmHg corresponds to pressure that is further from atmospheric pressure (e.g., -80 mmHg is more than - 60 mmHg). In some embodiments, local ambient atmospheric pressure is used as a reference point, and such local atmospheric pressure may not necessarily be, for example, 760 mmHg.

[0064] The negative pressure range for some embodiments of the present disclosure can be approximately -80 mmHg, or between about -20 mmHg and -200 mmHg. Note that these pressures are relative to normal ambient atmospheric pressure, which can be 760 mmHg. Thus, - 200 mmHg would be about 560 mmHg in practical terms. In some embodiments, the pressure range can be between about -40 mmHg and -150 mmHg. Alternatively, a pressure range of up to -75 mmHg, up to -80 mmHg or over -80 mmHg can be used. Also in other embodiments a pressure range of below -75 mmHg can be used. Alternatively, a pressure range of over approximately - 100 mmHg, or even -150 mmHg, can be supplied by the negative pressure apparatus.

[0065] In some embodiments of wound closure devices described herein, increased wound contraction can lead to increased tissue expansion in the surrounding wound tissue. This effect may be increased by varying the force applied to the tissue, for example by varying the negative pressure applied to the wound over time, possibly in conjunction with increased tensile forces applied to the wound via embodiments of the wound closure devices. In some embodiments, negative pressure may be varied over time for example using a sinusoidal wave, square wave, or in synchronization with one or more patient physiological indices (e.g., heartbeat). Examples of such applications where additional disclosure relating to the preceding may be found include U.S. Patent No. 8,235,955, titled “Wound treatment apparatus and method," issued on August 7, 2012; and U.S. Patent No. 7,753,894, titled "Wound cleansing apparatus with stress,” issued July 13, 2010. The disclosures of both of these patents are hereby incorporated by reference in their entirety. [0066] Embodiments of the wound dressings, wound dressing components, wound treatment apparatuses and methods described herein may also be used in combination or in addition to those described in International Application No. PCT/IB2013/001469, filed May 22, 2013, published as WO 2013/175306 A2 on November 28, 2013, titled “APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY,” International Application No. PCT/IB2013/002060, filed on July 31, 2013, published as WO2014/020440, entitled “WOUND DRESSING,” the disclosures of which are hereby incorporated by reference in their entireties. Embodiments of the wound dressings, wound treatment apparatuses and methods described herein may also be used in combination or in addition to those described in US Patent No. 9,061,095, titled "WOUND DRESSING AND METHOD OF USE," issued on June 23, 2015; and U S. Application Publication No. 2016/0339158, titled “FLUIDIC CONNECTOR FOR NEGATIVE PRESSURE WOUND THERAPY,” published on November 24, 2016, the disclosures of which are hereby incorporated by reference in its entirety, including further details relating to embodiments of wound dressings, the wound dressing components and principles, and the materials used for the wound dressings.

[0067] Additionally, some embodiments related to TNP wound treatment comprising a wound dressing in combination with a pump or associated electronics described herein may also be used in combination or in addition to those described in International Publication No. WO 2016/174048 Al, entitled “REDUCED PRESSURE APPARATUSES”, published on November 3, 2016, the entirety of which is hereby incorporated by reference. In some of these embodiments, the pump or associate electronic components may be integrated into the wound dressing to provide a single article to be applied to the wound.

Multi-Layered Wound Dressings for NPWT

[0068] Figure 3 illustrates an example of a negative pressure wound therapy system 700. The system includes a wound cavity 710 covered by a wound dressing 720, which can be a dressing according to any of the examples described herein. The dressing 720 can be positioned on or inside the wound cavity 710 and further seal the wound cavity so that negative pressure can be maintained in the wound cavity. For example, a film layer of the wound dressing 720 can provide substantially fluid impermeable seal over the wound cavity 710. In some embodiments, a wound filler, such as a layer of foam or gauze, may be utilized to pack the wound. The wound filler may include a multi-care WCL as described herein this section or elsewhere in the specification. For example, in a traditional negative pressure wound therapy system utilizing foam or gauze, such as the Smith & Nephew RENASYS Negative Pressure Wound Therapy System utilizing foam (RENASYS-F) or gauze (RENASYS-G), the foam or gauze may be supplemented with a multi-care WCL layer as described above. When supplementing a foam or gauze layer or other wound packing material, the multi-care WCL layer may either be separately inserted into the wound or may be pre-attached with the wound packing material for insertion into the wound.

[0069] A single or multi lumen tube or conduit 740 connects the wound dressing 720 with a negative pressure device 750 configured to supply reduced pressure. The negative pressure device 750 includes a negative pressure source. The negative pressure device 750 can be a canisterless device (meaning that exudate is collected in the wound dressing and/or is transferred via the tube 740 for collection to another location). In some embodiments, the negative pressure device 750 can be configured to include or support a canister. Additionally, in any of the embodiments disclosed herein, the negative pressure device 750 can be fully or partially embedded in, mounted to, or supported by the wound dressing 720.

[0070] The conduit 740 can be any suitable article configured to provide at least a substantially sealed fluid flow path or pathway between the negative pressure device 750 and the wound cavity 710 so as to supply reduced pressure to the wound cavity. The conduit 740 can be formed from polyurethane, PVC, nylon, polyethylene, silicone, or any other suitable rigid or flexible material. In some embodiments, the wound dressing 720 can have a port configured to receive an end of the conduit 740. For example, a port can include a hole in the fdm layer. In some embodiments, the conduit 740 can otherwise pass through and/or under a film layer of the wound dressing 720 to supply reduced pressure to the wound cavity 710 so as to maintain a desired level of reduced pressure in the wound cavity. In some embodiments, at least a part of the conduit 740 is integral with or attached to the wound dressing 720.

[0071] Figure 4A illustrates an embodiment of a negative pressure wound treatment system 10 employing a wound dressing 100 in conjunction with a fluidic connector 110. Additional examples related to negative pressure wound treatment comprising a wound dressing in combination with a pump as described herein may also be used in combination or in addition to those described in US Patent No. 9,061,095, which is incorporated by reference in its entirety. Here, the fluidic connector 110 may comprise an elongate conduit, more preferably a bridge 120 having a proximal end 130 and a distal end 140, and an applicator 180 at the distal end 140 of the bridge 120. The system 10 may include a source of negative pressure such as a pump or negative pressure unit 150 capable of supplying negative pressure. The pump may comprise a canister or other container for the storage of wound exudates and other fluids that may be removed from the wound. A canister or container may also be provided separate from the pump. In some embodiments, the pump 150 can be a canisterless pump such as the PICO™ pump, as sold by Smith & Nephew. The pump 150 may be connected to the bridge 120 via a tube, or the pump 150 may be connected directly to the bridge 120. In use, the dressing 100 is placed over a suitably- prepared wound, which may in some cases be filled with a wound packing material such as foam or gauze as described above. The applicator 180 of the fluidic connector 110 has a sealing surface that is placed over an aperture in the dressing 100 and is sealed to the top surface of the dressing 100. Either before, during, or after connection of the fluidic connector 110 to the dressing 100, the pump 150 is connected via the tube to the coupling 160, or is connected directly to the bridge 120. The pump is then activated, thereby supplying negative pressure to the wound. Application of negative pressure may be applied until a desired level of healing of the wound is achieved.

[0072] As shown in Figure 4B, the fluidic connector 110 preferably comprises an enlarged distal end, or head 140 that is in fluidic communication with the dressing 100 as will be described in further detail below. In one embodiment, the enlarged distal end has a round or circular shape. The head 140 is illustrated here as being positioned near an edge of the dressing 100, but may also be positioned at any location on the dressing. For example, some embodiments may provide for a centrally or off-centered location not on or near an edge or corner of the dressing 100. In some embodiments, the dressing 10 may comprise two or more fluidic connectors 110, each comprising one or more heads 140, in fluidic communication therewith. In a preferred embodiment, the head 140 may measure 30mm along its widest edge. The head 140 forms at least in part the applicator 180, described above, that is configured to seal against a top surface of the wound dressing.

[0073] Figure 4C illustrates a cross-section through a wound dressing 100 similar to the wound dressing 10 as described in International Patent Publication WO2013175306 A2, which is incorporated by reference in its entirety, along with fluidic connector 110. The wound dressing 100, which can alternatively be any wound dressing embodiment disclosed herein or any combination of features of any number of wound dressing embodiments disclosed herein, can be located over a wound site to be treated. The dressing 100 may be placed as to form a sealed cavity over the wound site. In a preferred embodiment, the dressing 100 comprises a top or cover layer, or backing layer 220 attached to an optional wound contact layer 222, both of which are described in greater detail below. These two layers 220, 222 are preferably joined or sealed together so as to define an interior space or chamber. This interior space or chamber may comprise additional structures that may be adapted to distribute or transmit negative pressure, store wound exudate and other fluids removed from the wound, and other functions which will be explained in greater detail below. Examples of such structures, described below, include a transmission layer 226 and an absorbent layer 221.

[0074] As used herein the upper layer, top layer, or layer above refers to a layer furthest from the surface of the skin or wound while the dressing is in use and positioned over the wound. Accordingly, the lower surface, lower layer, bottom layer, or layer below refers to the layer that is closest to the surface of the skin or wound while the dressing is in use and positioned over the wound.

[0075] As illustrated in Figure 4C, the wound contact layer 222 can be a polyurethane layer or polyethylene layer or other flexible layer which is perforated, for example via a hot pin process, laser ablation process, ultrasound process or in some other way or otherwise made permeable to liquid and gas. The wound contact layer 222 has a lower surface 224 and an upper surface 223. The perforations 225 preferably comprise through holes in the wound contact layer 222 which enable fluid to flow through the layer 222. The wound contact layer 222 helps prevent tissue ingrowth into the other material of the wound dressing. Preferably, the perforations are small enough to meet this requirement while still allowing fluid to flow therethrough. For example, perforations formed as slits or holes having a size ranging from 0.025 mm to 1.2 mm are considered small enough to help prevent tissue ingrowth into the wound dressing while allowing wound exudate to flow into the dressing. In some configurations, the wound contact layer 222 may help maintain the integrity of the entire dressing 100 while also creating an air tight seal around the absorbent pad in order to maintain negative pressure at the wound.

[0076] Some embodiments of the wound contact layer 222 may also act as a carrier for an optional lower and upper adhesive layer (not shown). For example, a lower pressure sensitive adhesive may be provided on the lower surface 224 of the wound dressing 100 whilst an upper pressure sensitive adhesive layer may be provided on the upper surface 223 of the wound contact layer. The pressure sensitive adhesive, which may be a silicone, hot melt, hydrocolloid or acrylic based adhesive or other such adhesives, may be formed on both sides or optionally on a selected one or none of the sides of the wound contact layer. When a lower pressure sensitive adhesive layer is utilized may be helpful to adhere the wound dressing 100 to the skin around a wound site. In some embodiments, the wound contact layer may comprise perforated polyurethane film. The lower surface of the film may be provided with a silicone pressure sensitive adhesive and the upper surface may be provided with an acrylic pressure sensitive adhesive, which may help the dressing maintain its integrity. In some embodiments, a polyurethane film layer may be provided with an adhesive layer on both its upper surface and lower surface, and all three layers may be perforated together.

[0077] A transmission layer 226 can be located above the wound contact layer 222. In some embodiments, the transmission layer can be a porous material. As used herein the transmission layer can be referred to as a spacer layer and the terms can be used interchangeably to refer to the same component described herein. This transmission layer 226 allows transmission of fluid including liquid and gas away from a wound site into upper layers of the wound dressing. In particular, the transmission layer 226 preferably ensures that an open-air channel can be maintained to communicate negative pressure over the wound area even when the absorbent layer has absorbed substantial amounts of exudates. The layer 226 should preferably remain open under the typical pressures that will be applied during negative pressure wound therapy as described above, so that the whole wound site sees an equalized negative pressure. The layer 226 may be formed of a material having a three-dimensional structure. For example, a knitted or woven spacer fabric (for example Baltex 7970 weft knitted polyester) or a non-woven fabric could be used. The three-dimensional material can comprise a 3D spacer fabric material similar to the material described in International Publication WO 2013/175306 A2 and International Publication W02014/020440, the disclosures of which are incorporated by reference in their entireties.

[0078] In certain embodiments, the wound dressing 100 may incorporate or comprise a multi-care WCL as described herein this section or elsewhere in the specification. One of skill in the art will understand that the wound dressing 100 may incorporate any of the multi-care WCLs disclosed herein this section or elsewhere in the specification. One of skill in the art will also understand that the multi-care WCL may be incorporated as a whole component layer or a part of a component layer. In some embodiments, the multi-care WCL layer may be provided below the transmission layer 226. In some embodiments, the multi-care WCL layer may be provided above the wound contact layer 222. In some embodiments, the multi-care WCL layer may replace the transmission layer 226, such that the multi-care WCL layer is provided between an absorbent layer 221 (described further below) and the wound contact layer 222. In some embodiments, the multi care WCL layer can supplement or replace the absorbent layer 221. In some embodiments, the wound dressing 100 does not have the wound contact layer 222, and the multi-care WCL layer may be the lowermost layer of the wound dressing 100. The multi-care WCL may have same or substantially similar size and shape with the transmission layer 226 and/or the absorbent layer 221.

[0079] The multi-care WCL layer may be constructed to be flexible but stiff enough to withstand negative pressure, such that the multi-care WCL is not collapsed excessively and thereby transmits negative pressure sufficiently to the wound when negative pressure is supplied to the wound dressing 100. The multi-care WCL layer may be constructed to include sufficient number or size of pores to enable transmission of negative pressure through it. Further, the multi-care WCL layer may have suitable thickness to transmit enough negative pressure to the wound. For example, the multi-care WCL layer may have a thickness of 1 mm to 10 mm, or 1 mm to 7 mm, or 1.5 mm to 7 mm, or 1.5 mm to 4 mm, or 2 mm to 3 mm. In some embodiments, the multi -care WCL may have a thickness of approximately 2 mm.

[0080] In some embodiments, the layer 221 of absorbent material is provided above the transmission layer 226. The absorbent material, which can comprise a foam or non-woven natural or synthetic material, and which may optionally comprise a super-absorbent material, forms a reservoir for fluid, particularly liquid, removed from the wound site. In some embodiments, the layer 221 may also aid in drawing fluids towards the backing layer 220.

[0081] The material of the absorbent layer 221 may also prevent liquid collected in the wound dressing 100 from flowing freely within the dressing, and preferably acts so as to contain any liquid collected within the dressing. The absorbent layer 221 also helps distribute fluid throughout the layer via a wicking action so that fluid is drawn from the wound site and stored throughout the absorbent layer. This helps prevent agglomeration in areas of the absorbent layer. The capacity of the absorbent material must be sufficient to manage the exudates flow rate of a wound when negative pressure is applied. Since in use the absorbent layer experiences negative pressures the material of the absorbent layer is chosen to absorb liquid under such circumstances. A number of materials exist that are able to absorb liquid when under negative pressure, for example superabsorber material. The absorbent layer 221 may typically be manufactured from ALLEVYN™ foam, Freudenberg 114-224-4 or Chem-Posite™l lC-450. In some embodiments, the absorbent layer 221 may comprise a composite comprising superabsorbent powder, fibrous material such as cellulose, and bonding fibers. In a preferred embodiment, the composite is an air- laid, thermally-bonded composite.

[0082] In some embodiments, the absorbent layer 221 is a layer of non- woven cellulose fibers having super-absorbent material in the form of dry particles dispersed throughout. Use of the cellulose fibers introduces fast wicking elements which help quickly and evenly distribute liquid taken up by the dressing. The juxtaposition of multiple strand-like fibers leads to strong capillary action in the fibrous pad which helps distribute liquid. In this way, the super-absorbent material is efficiently supplied with liquid. The wicking action also assists in bringing liquid into contact with the upper cover layer to aid increase transpiration rates of the dressing.

[0083] An aperture, hole, or orifice 227 is preferably provided in the backing layer 220 to allow a negative pressure to be applied to the dressing 100. The fluidic connector 110 is preferably attached or sealed to the top of the backing layer 220 over the orifice 227 made into the dressing 100, and communicates negative pressure through the orifice 227. A length of tubing may be coupled at a first end to the fluidic connector 110 and at a second end to a pump unit (not shown) to allow fluids to be pumped out of the dressing. Where the fluidic connector is adhered to the top layer of the wound dressing, a length of tubing may be coupled at a first end of the fluidic connector such that the tubing, or conduit, extends away from the fluidic connector parallel or substantially to the top surface of the dressing. The fluidic connector 110 may be adhered and sealed to the backing layer 220 using an adhesive such as an acrylic, cyanoacrylate, epoxy, UV curable or hot melt adhesive. The fluidic connector 110 may be formed from a soft polymer, for example a polyethylene, a polyvinyl chloride, a silicone or polyurethane having a hardness of 30 to 90 on the Shore A scale. In some embodiments, the fluidic connector 110 may be made from a soft or conformable material.

[0084] Optionally, the absorbent layer 221 includes at least one through hole 228 located so as to underlie the fluidic connector 110. The through hole 228 may in some embodiments be the same size as the opening 227 in the backing layer, or may be bigger or smaller. As illustrated in Figure 4C a single through hole can be used to produce an opening underlying the fluidic connector 110. It will be appreciated that multiple openings could alternatively be utilized. Additionally, should more than one port be utilized according to certain embodiments of the present disclosure one or multiple openings may be made in the absorbent layer in registration with each respective fluidic connector. Although not essential to certain embodiments of the present disclosure the use of through holes in the super-absorbent layer may provide a fluid flow pathway which remains unblocked in particular when the absorbent layer is near saturation.

[0085] The aperture or through-hole 228 is preferably provided in the absorbent layer

221 beneath the orifice 227 such that the orifice is connected directly to the transmission layer 226 as illustrated in Figure 4C. This allows the negative pressure applied to the fluidic connector 110 to be communicated to the transmission layer 226 without passing through the absorbent layer 221. This ensures that the negative pressure applied to the wound site is not inhibited by the absorbent layer as it absorbs wound exudates. In other embodiments, no aperture may be provided in the absorbent layer 221, or alternatively a plurality of apertures underlying the orifice 227 may be provided. In further alternative embodiments, additional layers such as another transmission layer or an obscuring layer such as described with reference to Figures 6A-6B and in International Patent Publication W02014/020440, the entirety of which is hereby incorporated by reference, may be provided over the absorbent layer 221 and beneath the backing layer 220.

[0086] The backing layer 220 is preferably gas impermeable, but moisture vapor permeable, and can extend across the width of the wound dressing 100. The backing layer 220, which may for example be a polyurethane fdm (for example, Elastollan SP9109) having a pressure sensitive adhesive on one side, is impermeable to gas and this layer thus operates to cover the wound and to seal a wound cavity over which the wound dressing is placed. In this way, an effective chamber is made between the backing layer 220 and a wound site where a negative pressure can be established. The backing layer 220 is preferably sealed to the wound contact layer

222 in a border region around the circumference of the dressing, ensuring that no air is drawn in through the border area, for example via adhesive or welding techniques. The backing layer 220 protects the wound from external bacterial contamination (bacterial barrier) and allows liquid from wound exudates to be transferred through the layer and evaporated from the film outer surface. The backing layer 220 preferably comprises two layers; a polyurethane fdm and an adhesive pattern spread onto the film. The polyurethane film is preferably moisture vapor permeable and may be manufactured from a material that has an increased water transmission rate when wet. In some embodiments, the moisture vapor permeability of the backing layer increases when the backing layer becomes wet. The moisture vapor permeability of the wet backing layer may be up to about ten times more than the moisture vapor permeability of the dry backing layer.

[0087] The absorbent layer 221 may be of a greater area than the transmission layer 226, such that the absorbent layer overlaps the edges of the transmission layer 226, thereby ensuring that the transmission layer does not contact the backing layer 220. This provides an outer channel of the absorbent layer 221 that is in direct contact with the wound contact layer 222, which aids more rapid absorption of exudates to the absorbent layer. Furthermore, this outer channel ensures that no liquid is able to pool around the circumference of the wound cavity, which may otherwise seep through the seal around the perimeter of the dressing leading to the formation of leaks. As illustrated in Figure 4C, the absorbent layer 221 may define a smaller perimeter than that of the backing layer 220, such that a boundary or border region is defined between the edge of the absorbent layer 221 and the edge of the backing layer 220.

[0088] As shown in Figure 4C, one embodiment of the wound dressing 100 comprises an aperture 228 in the absorbent layer 221 situated underneath the fluidic connector 110. In use, for example when negative pressure is applied to the dressing 100, a wound facing portion of the fluidic connector may thus come into contact with the transmission layer 226, which can thus aid in transmitting negative pressure to the wound site even when the absorbent layer 221 is filled with wound fluids. Some embodiments may have the backing layer 220 be at least partly adhered to the transmission layer 226. In some embodiments, the aperture 228 is at least 1 -2 mm larger than the diameter of the wound facing portion of the fluidic connector 11 , or the orifice 227.

[0089] In particular for embodiments with a single fluidic connector 110 and through hole, it may be preferable for the fluidic connector 110 and through hole to be located in an off- center position as illustrated in Figure 4B. Such a location may permit the dressing 100 to be positioned onto a patient such that the fluidic connector 110 is raised in relation to the remainder of the dressing 100. So positioned, the fluidic connector 110 and the filter 214 may be less likely to come into contact with wound fluids that could prematurely occlude the filter 214 so as to impair the transmission of negative pressure to the wound site.

[0090] Similar to the embodiments of wound dressings described above, some wound dressings comprise a perforated wound contact layer with silicone adhesive on the skin-contact face and acrylic adhesive on the reverse. In some embodiments, the wound contact layer may be constructed from polyurethane, polyethylene or polyester. Above this bordered layer sits a transmission layer. Above the transmission layer, sits an absorbent layer. The absorbent layer can include a superabsorbent non-woven (NW) pad. The absorbent layer can over-border the transmission layer by approximately 5mm at the perimeter. The absorbent layer can have an aperture or through -hole toward one end. The aperture can be about 10 mm in diameter. Over the transmission layer and absorbent layer lies a backing layer. The backing layer can be a high moisture vapor transmission rate (MVTR) fdm, pattern coated with acrylic adhesive. The high MVTR fdm and wound contact layer encapsulate the transmission layer and absorbent layer, creating a perimeter border of approximately 20 mm. The backing layer can have a 10 mm aperture that overlies the aperture in the absorbent layer. Above the hole can be bonded a fluidic connector that comprises a liquid-impermeable, gas-permeable semi-permeable membrane (SPM) or filter that overlies the aforementioned apertures.

[0091] In another example, the wound dressing may be provided without the foam layer. The foam layer helps to transport exudate away from the wound. However in some cases, and depending on the severity of a wound, the absorbent layer may sufficiently draw exudate from the wound without the need for the foam layer.

[0092] Although in the examples described above, the support layer is heat laminated to the absorbent layer via a bonding layer, other laminating techniques may be suitable. For example, the bonding layer may include a pressure sensitive adhesive. In this case, heat may not be required to laminate the support layer and adhesive layer together.

[0093] Although in the example described above, the net layer has been described as having a substantially hexagonal shaped structure, other geometric structures may also be suitable. With other geometric structures, the apertures may also have different geometric shapes.

[0094] In another example, the wound dressing may include more than one support layer to provide support to other layers in the wound dressing. For example, a first support layer may be located between the liquid impermeable film layer and the absorbent layer, and a further support layer may be located between the absorbent layer and the fluid transport layer (foam layer). This may help to support the absorbent layer from both sides to further reduce shrinking of the absorbent layer.

[0095] Any of the examples described herein may be adapted for use with a negative pressure system (sometimes referred to as a reduced pressure system) including a source of negative pressure, such as a negative pressure pump. For example, the film layer may include a negative pressure interface, such as a port, to which a negative pressure supply tube may be connected. The supply tube may be connected to a negative pressure source so that, in use, the negative pressure source applies a negative pressure to the wound dressing between the film layer and the wound to help draw wound exudate away from the wound and into the absorbent layer of the dressing.

Testing Apparatus

[0096] As explained above, a multi-care WCL may be compatible with NPWT, removable as a single piece, and capable of delivering a treatment to the wound such as the delivery of Cadexomer Iodine. Also as explained above, Cadexomer Iodine may have many benefits for wound treatment, and thus is a desirable molecule for delivery to a wound bed. Many testing techniques are known in the art to evaluate the properties of wound contact layers and dressings, such as the multi-care WCL described above. However, to test such a multi-care WCL using methodology known in the art can be challenging and known existing techniques may not provide full visualization via a computed tomography (CT) scan or other visualization methods.

[0097] Figure 5A depicts a wound model 3000 for use in/as a testing apparatus for testing a multi-care WCL and/or a wound dressing. Such a wound model may be constructed from any suitable material that is readily visible via CT scan, for example high-density polyethylene (HOPE). HDPE is an advantageous material for CT scanning, because it allows passage of X-rays with minimal attenuation. However, one of skill in the art will understand that any suitable material may be used, such as another polymer that allows for passage of X-rays with minimal attenuation. For example, different materials, such as polypropylene, polystyrene, polyesters, or pure graphite may be used to construct the wound model. In some embodiments, the wound model may be constructed from one of the materials described herein, then overlaid by an electrically conductive material such as graphite (carbon) electrical tracks or circuitry in order to provide electrical contacts for any suitable dressing or multi-care WCL employing electrical components requiring connection. In certain embodiments, the electrically conductive material and/or electrical tracks and/or circuitry may be used to provide heating of the dressing or multi-care WCL via resistance heating of the conductive material. As described further below, one of skill in the art will also understand that such a wound model may be configured to allow for the application of negative pressure, irrigation, and pressure sensing while positioned within a CT scanner and while testing a multi-care WCL.

[0098] In embodiments, the wound model may be constructed such that it fits within a small-scale CT scanner. Such a wound model may include legs 3002, for mounting the wound model, for example mounting within a CT scan to allow for rotation of the wound model. Legs may serve to prop up the wound model and allow delivery tubes connected to the connectors (described below) to function without bending. In certain embodiments, one, two, three, four, five or more than five legs may be incorporated into the wound model. The wound model may also include a base 3004, the base may be surrounded by a circular wall 3006, thereby forming a cavity for placement of a suitably shaped multi-care WCL or wound dressing over the base. The legs 3002 may be positioned under the base and/or under the wall. The legs may be removable and/or configured for fixation such that the wound model may be easily rotated to provide 360 degree views within a CT scanner. In embodiments, the wall may be circular, rectangular, polygonal, or any other suitable shape. The base may further include a plurality of openings 3008 for delivery of fluid (such as for irrigation) and/or delivery of negative pressure and/or pressure sensing and/or an air bleed (for example, a controlled air bleed) and/or delivery of a gas (such as a therapeutic gas). Such openings may be in any suitable orientation, such as vertical, horizontal, or in-between. Further, in certain embodiments, the openings may be threaded. The openings may be filled with connectors 3014, such as shown below in Figure 5D, to allow for connection to tubing for irrigation/aspiration. In embodiments, a film may also be layered over the base and/or the wall such as a Teflon film or EU33 Renasys film. The film may also serve to seal the connector or connectors, such that gas and/or liquid does not leak. In certain embodiments, the openings described herein may be positioned at other locations on the wound model. For example, the openings may be positioned around the circumference of the wound model. For example, openings may be positioned on the wall, such as near the bottom, top, or middle of the wall. Additionally, openings may be positioned around the perimeter of the base near the wall. It would also be possible to have a lid on the system to enclose it (and have inlets and outlets coming in through this). In certain embodiments, a lid (not shown) may be positioned over the top of the wound model, to assist with sealing the system whilst under negative pressure. Additionally, a lid may also provide a place for a suitable pump (such as a PICO pump) to be positioned. [0099] Irrigation may be provided by a pump connected to a reservoir of any suitable liquid, while negative pressure may be provided by a suitable vacuum pump. Additionally the connectors 3014 may be in communication with a pressure sensor, for monitoring pressure in the cavity. Other suitable sensors may also be employed, such as a flow sensor, temperature sensor, pH sensor, humidity sensor, or other suitable sensors. Such sensors may be positioned on the base, the wall, or any suitable location and may be used in any suitable combination. In certain embodiments, there may be more than one of a single type of sensor, such as two, three, four, five, or more pressure sensors. In embodiments, the base may have one, two, three, four, or more than four openings. During testing, a multi-care WCL may be cut to size and placed over the base portion, thereby allowing for testing under negative pressure and instillation conditions. One of skill in the art will understand that negative pressure and/or instillation may be delivered in alternating fashion, simultaneously, continuously, and/or intermittently. Further, negative pressure may be varied dynamically such that it is applied at different thresholds, such as high or low negative pressure within any suitable range disclosed herein. For example, negative pressure may be applied dynamically in a cyclic manner. In some embodiments, instillation may also be applied in a cyclic manner. One of skill in the art will understand that the testing apparatus may be connected to a controller, the controller configured to control the sensors, irrigation, negative pressure, and other suitable actions described herein. The controller may be configured to deliver negative pressure and irrigation in any manner described herein, such as alternating fashion, simultaneously, continuously, and/or intermittently. Further the controller may utilize any of the sensors described herein to detect a parameter and then deliver negative pressure / instillation in response to such a parameter. In certain embodiments, the wound model may be connected to a fluid pump or gravity fed fluid header tank to enable dynamic control of fluid ingress to the wound dressing. One of skill in the art will understand that such an arrangement may also be co-mounted with the wound model within a particular CT scanner. In certain embodiments, the external surface shape of the wound model may be modified to accommodate further ancillary dressing components, vacuum pump devices, fluid reservoirs, power supplies/battery packs, tubing management clips/holes/fixings, or other suitable components.

[0100] Figure 5B depicts a top view of wound model 3000. Here, example dimensions are included in the image; however, one of skill in the art will understand that such dimensions may be varied. For example, the outer diameter 3010 of the wound model, shown as 90mm in the figure, may vary from about 50 to 200 mm, such as 60 to 150mm, 80 to 120mm, or about 90 mm. For example, the inner diameter 3012 of the wound model, shown as 75mm in the figure, may vary from about 25 to 175 mm, such as 50 to 125mm, 60 to 100mm, or about 75mm. The openings 3008 within the base may have a diameter ranging from about 2 to 12mm, about 4 to 10mm, about 5 to 8mm, or about 6mm.

[0101] Figure 5C depicts a side view of wound model 3000. Here the height of the wall 3006 from the base 3004 to the top may range from about 5 to 50mm, 10 to 40mm, 20 to 30mm, or about 23mm. The depth of the base 3004 may range from about 1 to 15mm, 2 to 12mm, 4 to 10mm, or about 7mm. The length of the legs 3002 may range from about 10 to 50mm, 20 to 40 mm, 30 to 35mm, or about 33 mm. The diameter of the legs 3002 may range from about 1 to 15mm, 3 to 12mm, 5 to 10mm, or about 7.5mm. Figure 5D is a photograph from different angles of the wound model of Figures 5A-5C. Here, the connectors 3014 are visible. As described above, such connectors may be used for NPWT, instillation, controlled or uncontrolled air bleed, gas delivery (such as therapeutic gases), and/or pressure monitoring. Figures 6A-6F are computer- reconstructed images of the wound model of Figures 5A-5D, showing different views and angles of the wound model described above.

[0102] Figure 7 depicts an embodiment of a wound model 4000, similar to the wound model of Figures 5A-6F. However, the wound model 4000 of Figure 7 may have flat segments 4002 of the wall surrounding the cavity. Further, the dimensions of wound model 4000 may be within any range described above in relation to wound model 3000 in Figures 5A-6F, such as for example, the approximate dimensions shown in Figure 7.

Terminology

[0103] Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference. Aspects of the disclosure can be modified, if necessary, to employ the systems, functions, and concepts of the various references described herein to provide yet further implementations.

[0104] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0105] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of protection. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. For example, the actual steps or order of steps taken in the disclosed processes may differ from those shown in the figure. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

[0106] Although the present disclosure includes certain embodiments, examples and applications, it will be understood by those skilled in the art that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments or uses and obvious modifications and equivalents thereof, including embodiments which do not provide all of the features and advantages set forth herein. Accordingly, the scope of the present disclosure is not intended to be limited by the described embodiments, and may be defined by claims as presented herein or as presented in the future.

[0107] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, or steps. Thus, such conditional language is not generally intended to imply that features, elements, or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, or steps are included or are to be performed in any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. Likewise the term “and/or” in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list. Further, the term “each,” as used herein, in addition to having its ordinary meaning, can mean any subset of a set of elements to which the term “each” is applied. Additionally, the words “herein,” “above,” "below," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application.

[0108] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

[0109] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degree.

[0110] Any of the embodiments described herein can be used with a canister or without a canister. Any of the dressing embodiments described herein can absorb and store wound exudate.

[0111] The scope of the present disclosure is not intended to be limited by the description of certain embodiments and may be defined by the claims. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

[0112] Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the principles and features disclosed herein. Certain embodiments of the disclosure are encompassed in the claim set listed below or presented in the future. Certain embodiments of the disclosure are encompassed in the claims presented at the end of this specification, or in other claims presented at a later date.

Claims

WHAT IS CLAIMED IS:

1. A testing apparatus, comprising: a circular wall surrounding a base, the base comprising a plurality of openings, the plurality of openings comprising a negative pressure opening configured to connect to a source of negative pressure; a plurality of legs extending from the wall; a wound contact layer positioned over the openings; and wherein the wall, base, and legs are constructed from a high density polymer, the high density polymer configured to be readily visible in a computed tomography scan and provide minimal attenuation of X-rays passing therethrough.

2. The testing apparatus of Claim 1 , wherein the high density polymer is selected from the group consisting of high density polyethylene, high density polypropylene, high density polystyrene, and high density polyester.

3. The testing apparatus of Claim 2, wherein the high density polymer is high density polyethylene.

4. The testing apparatus of any one of the previous claims, wherein the wall, base, and legs are coated in a conductive layer, the conductive layer comprising an electrically conductive material.

5. The testing apparatus of Claim 4, wherein the electrically conductive material is graphite.

6. The testing apparatus of Claims 4-5, wherein the conductive layer is configured to deliver heat to the wound contact layer.

7. The testing apparatus of any one of the previous claims, wherein the plurality of openings comprise an irrigation opening, the irrigation opening configured to connect to an irrigant source.

8. The testing apparatus of any one of the previous claims, wherein the plurality of openings comprise a sensing opening, the sensing opening connected to a sensor configured to measure a parameter within the testing apparatus.

9. The testing apparatus of Claim 8, wherein the sensor comprises a sensor selected from the group consisting of a pressure sensor, a flow sensor, a temperature sensor, a pH sensor, and a humidity sensor.

10. The testing apparatus of any one of the previous claims, wherein the plurality of openings comprise a gas delivery opening, the gas delivery opening connected to a source of therapeutic gas.

11. The testing apparatus of any one of the previous claims, wherein the testing apparatus is configured to be sealed such that negative pressure may be delivered to the wound contact layer.

12. The testing apparatus of Claim 11 , further comprising a lid configured to be placed over the circular wall and seal the testing apparatus such that negative pressure may be delivered to the wound contact layer.

13. The testing apparatus of Claim 11, further comprising a cover layer configured to overlie and seal the testing apparatus such that negative pressure may be delivered to the wound contact layer

14. The testing apparatus of any one of the previous claims, wherein the plurality of legs comprise four legs.

15. The testing apparatus of any one of the previous claims, wherein the testing apparatus is configured to control the source of negative pressure and the instillation source such that negative pressure and irrigation may be delivered to the wound contact layer in alternating fashion.

16. The testing apparatus of Claims 1-15, wherein the testing apparatus is configured to control the source of negative pressure and the instillation source such that negative pressure and irrigation may be delivered simultaneously to the wound contact layer.

17. The testing apparatus of any one of the previous claims, wherein the wound contact layer comprises iodine.

18. A wound contact layer testing apparatus comprising one or more features of the foregoing description.

19. A method of operating a wound contact layer testing apparatus comprising one or more features of the foregoing description.