Asymmetric viscous wound dressing as well as preparation method and application thereof

Abstract

The invention provides an asymmetric viscous wound dressing as well as a preparation method and application thereof. An asymmetric viscous wound dressing includes a substrate having a cellosilk structure, and an adhesive layer including a first gel component and a second gel component, the first gel component derived from an adhesive composition including an acrylic compound, a photoinitiator, a crosslinking agent, and a first solvent. The asymmetric viscous wound dressing disclosed by the invention not only can firmly adhere to injuries, but also has good cytocompatibility and angiogenesis promoting capability, and can regenerate tissues, so that a remarkable tissue repair effect is generated.

Description

Technical Field

[0001] The present disclosure relates to an asymmetric adhesive wound dressing, a preparation method thereof, and uses thereof, belonging to the field of biomedical materials. Background Art

[0002] The human skin has multiple important functions, such as protecting the body from bacterial invasion, regulating body temperature, retaining moisture, and serving as the largest interface between the human body and the external environment. When the skin suffers severe trauma, the wound healing process does not naturally, orderly, and perfectly recover. Various adverse factors can lead to irregular and unsatisfactory wound healing. In such cases, using surgical sutures, wound dressings, and other instruments for surgical closure and isolating the wound from microbial contamination remains the gold standard for treating skin injuries. However, this method significantly increases the clinical cost and the patient burden.

[0003] As a natural-source cell scaffold carrier, acellular extracellular matrix materials have excellent biocompatibility and biodegradability and have been widely used in the treatment and care of various traumas and burns, such as Biodesign TM (COOK Corp., USA) and (Integra Corp., USA). These extracellular matrix materials retain a spatial structure suitable for cell growth and provide a rough porous fiber morphology, providing a porosity and permeability environment that helps accelerate wound healing.

[0004] Although significant progress has been made in the clinical and product transformation of extracellular matrix materials, most of these materials mainly act as "passive" carriers, promoting tissue regeneration by creating a favorable environment for cell growth, that is, in most cases, extracellular matrix materials act as a physical barrier for wound healing. In recent years, researchers have continuously incorporated active ingredients into extracellular matrix materials, such as drugs, functional peptides, exosomes, etc., to enhance the excellent antibacterial activity, angiogenesis ability, and cell recruitment ability of these scaffold materials, thereby achieving more effective promotion of wound healing.

[0005] Among the active ingredients, lithium saponite (LAP) nanomaterials, as a common natural clay, are rich in active elements such as magnesium (Mg) and silicon (Si). Due to the inherent electrostatic interaction on its surface, it can self-assemble into a hydrogel at a certain concentration. However, due to the easy shedding property of lithium saponite (LAP) nanomaterials, it is not yet possible to use lithium saponite (LAP) nanomaterials for wound dressings.

[0006] Severe tissue damage poses a major risk to human health. Traditional wound dressings are prone to falling off the wound tissue due to poor adhesion performance and lack of regeneration induction, and cannot achieve effective tissue regeneration, resulting in poor postoperative healing effects.

[0007] Therefore, it has become an urgent technical problem to study a wound dressing that can firmly adhere to injuries, has good cell compatibility and angiogenesis-promoting ability, and enables tissue regeneration. Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] In view of the technical problems existing in the prior art, such as poor adhesion performance, easy detachment from wound tissues, and lack of regeneration induction resulting in poor healing effects, etc., the present disclosure first provides an asymmetric adhesive wound dressing. The asymmetric adhesive wound dressing of the present disclosure can not only firmly adhere to injuries, but also has good cell compatibility and angiogenesis-promoting ability, and can enable tissue regeneration, thereby producing a significant tissue repair effect.

[0010] The present disclosure also provides a preparation method of the asymmetric adhesive wound dressing. The preparation method is simple and easy to implement, the raw materials are easy to obtain, and it is suitable for mass production.

[0011] Solutions for Solving the Problems

[0012] [1]. An asymmetric adhesive wound dressing, comprising:

[0013] A substrate, the substrate having a fibril structure, and,

[0014] An adhesive layer, the adhesive layer comprising a first gel component and a second gel component, the first gel component being derived from an adhesive composition, the adhesive composition comprising an acrylic compound, a photoinitiator, a crosslinking agent, and a first solvent.

[0015] [2]. The asymmetric adhesive wound dressing according to [1] above, wherein, based on the total mass of the first solvent being 100%, the content of the acrylic compound is 10% - 60%, the content of the photoinitiator is 0.01% - 0.5%, and the content of the crosslinking agent is 0.05% - 6%.

[0016] [3]. The asymmetric adhesive wound dressing according to [1] or [2] above, wherein the acrylic compound comprises one or a combination of two or more of acrylic acid, polyacrylamide, polyacrylic acid, and hydroxyethyl polymethacrylate; and / or,

[0017] The crosslinking agent comprises one or a combination of two or more of gelatin methacrylate, hyaluronic acid methacrylate, polycaprolactone diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, and N,N'-methylenebisacrylamide; and / or,

[0018] The photoinitiator includes ketone photoinitiators, preferably including one or a combination of two or more of α-ketoglutaric acid, 2,2-dimethoxy-2-phenylacetophenone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0019] [4] The asymmetric adhesive wound dressing according to any one of the above [1]-[3], wherein the second gel component is derived from a clay mineral containing magnesium element, lithium element, and silicon element and a second solvent;

[0020] Preferably, the clay mineral includes laponite nanoparticles;

[0021] More preferably, the particle size of the laponite nanoparticles is 5-50 nm, preferably 5-20 nm.

[0022] [5] The asymmetric adhesive wound dressing according to the above [4], wherein, based on the total mass of the second solvent being 100%, the content of the clay mineral is 1-15%.

[0023] [6] The asymmetric adhesive wound dressing according to the above [4] or [5], wherein the mass ratio of the clay mineral to the acrylic compound is 1:10-1:200, preferably 1:30-1:150.

[0024] [7] A method for preparing an asymmetric adhesive wound dressing according to any one of the above [1]-[6], which includes the step of mixing the components of the adhesive layer and then compounding and molding with a substrate;

[0025] Preferably, the preparation method includes the following steps:

[0026] The step of obtaining the first gel component;

[0027] The step of obtaining the second gel component;

[0028] Mixing the first gel component and the second gel component to obtain a mixed product;

[0029] Making the mixed product present on at least one surface of the substrate, and obtaining an asymmetric adhesive wound dressing after a chemical reaction.

[0030] [8] The preparation method according to the above [7], wherein the first gel component includes an acrylic acid prepolymerization solution, and the acrylic acid prepolymerization solution is prepared by dissolving an acrylic compound, a photoinitiator, and a crosslinking agent in a first solvent; and / or,

[0031] The second gel component is obtained by dissolving a clay mineral containing magnesium element, lithium element and silicon element in a second solvent.

[0032] [9]. The preparation method according to [7] or [8] above, wherein the conditions of the chemical reaction include being carried out under the irradiation of ultraviolet light; preferably, the power of the ultraviolet light is 200 - 400 W and the wavelength is 350 - 400 nm.

[0033]

[10] . Use of an asymmetric adhesive wound dressing according to any one of [1] - [6] above for preparing a tissue repair product, especially for preparing a skin injury repair product, a hernia repair patch and a cardiovascular stent.

[0034] Effects of the invention

[0035] The asymmetric adhesive wound dressing of the present disclosure can not only firmly adhere to the injury, but also has good cell compatibility and angiogenesis-promoting ability, and can enable tissue regeneration, thus producing a significant tissue repair effect.

[0036] The preparation method of the asymmetric adhesive wound dressing of the present disclosure is simple and easy to implement, the raw materials are easy to obtain, and it is suitable for mass production. Brief description of the drawings

[0037] Figure 1 Shows a comparison of the application performance of a traditional wound dressing and the asymmetric adhesive wound dressing of the present disclosure, wherein the upper figure is a conventional wound dressing and the lower figure is an asymmetric adhesive wound dressing.

[0038] Figure 2 Shows the morphological characterization of lithium saponite nano-particles; wherein,

[0039] a is a transmission electron microscope (TEM) image;

[0040] b is an elemental mapping image and a high-angle annular dark field image (HAADF).

[0041] Figure 3 Shows a schematic diagram of the formation of a gel from lithium saponite nano-particles dispersed in water; wherein,

[0042] a is the overall appearance of the gelling process of lithium saponite at different concentrations;

[0043] b is the gelling time of lithium saponite nano-particles at different concentrations;

[0044] Figure 4 Shows a schematic diagram related to the tissue adhesion of polyacrylic acid gel; N = 4, **P ≤ 0.01; wherein,

[0045] a is the shear force-displacement curve of the polymerization of acrylic acid with different concentrations into polyacrylic acid gel;

[0046] b is the shear adhesion strength of polyacrylic acid gels with different acrylic acid concentrations.

[0047] Figure 5 Shows the SEM image of the adhesive layer of the asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ in Example 4.

[0048] Figure 6 Shows the preparation and morphological schematic diagram of the asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ in Example 4; wherein,

[0049] a is the schematic diagram of the preparation process of SIS / PAA 40％ / LAP 10％ in Example 4;

[0050] b is the appearance photo of SIS / PAA 40％ / LAP 10％ in Example 4;

[0051] c is the schematic diagram of the flexibility of SIS / PAA 40％ / LAP 10％ in Example 4;

[0052] d is the SEM image of the cross-section of SIS / PAA 40％ / LAP 10％ in Example 4;

[0053] e is the elemental mapping diagram of SIS / PAA 40％ / LAP 10％ in Example 4.

[0054] Figure 7 Shows the mechanical evaluation schematic diagram of SIS patch, the asymmetric adhesive wound dressing SIS / PAA 40％ in Example 1 and the asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ in Example 4; N = 5, ***P ≤ 0.001; wherein,

[0055] a is the tensile stress-strain curve of SIS, SIS / PAA 40％ , SIS / PAA 40％ / LAP 10％ in Example 4;

[0056] b is the Young's modulus of SIS, SIS / PAA 40％ , SIS / PAA 40％ / LAP 10％ in Example 4;

[0057] c is SIS, SIS / PAA 40％ , SIS / PAA 40％ / LAP 10％ 's tensile strength.

[0058] Figure 8 Shows SIS / PAA 40％ / LAP 10％ 's various adhesions including muscle, stomach, heart, lung.

[0059] Figure 9 Shows the schematic diagrams related to the tissue adhesion performance of the asymmetric adhesive wound dressings of Examples 1-4; wherein,

[0060] a is the schematic diagram of the shear force measurement based on ASTM F2255;

[0061] b is the shear adhesion strength of the asymmetric adhesive wound dressings of Examples 1-4;

[0062] c is the shear adhesion strength of various commercial tissue adhesive products and SIS / PAA 40％ / LAP 10％ ;

[0063] d is the schematic diagram of the determination of the bursting strength based on ASTM F2392;

[0064] e is the bursting strength of various commercial tissue adhesive products and SIS / PAA 40％ / LAP 10％ ;

[0065] f is the explanation of enhancing the mechanical strength by the internal chemical-physical double network structure.

[0066] Figure 10 Shows the SIS patch, the asymmetric adhesive wound dressing SIS / PAA of Example 1 40％ and the asymmetric adhesive wound dressing SIS / PAA of Example 4 40％ / LAP 10％ respectively co-cultured with fibroblasts L929 related schematic diagrams; N = 4, *P≤0.05; wherein,

[0067] a is the live / dead cell staining map when co-cultured with L929 in the conditioned medium for 1 day.

[0068] b is the cell proliferation with extended culture time (1-3 days) to show the cell growth condition.

[0069] Figure 11 Shows the SIS patch, the asymmetric adhesive wound dressing SIS / PAA of Example 1 40％and in vitro angiogenesis assay of the asymmetric adhesive wound dressing SIS / PAA of Example 4 40％ / LAP 10％ ; N = 4, **P ≤ 0.01, ***P ≤ 0.001; wherein,

[0070] a is the protocol of the conditioned medium for inducing angiogenesis differentiation;

[0071] b is the estimation of cell migration distance by cell scratch assay on HUVEC;

[0072] c is the semi - quantitative analysis of the migration distance based on Figure b above;

[0073] d is the determination of angiogenesis of HUVEC after 12 - hour incubation;

[0074] e is the semi - quantitative analysis of the blood vessel length based on Figure d above;

[0075] f is the immunofluorescence staining of VEGF (red) / cytoskeleton (green) / DAPI (blue) after 7 - day incubation;

[0076] g is the semi - quantitative analysis of VEGF fluorescence intensity based on Figure f above.

[0077] Figure 12 Shows the commercial product Tegaderm, SIS patch and the asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ of Example 4 for wound repair schematic diagram of full - thickness skin injury in rats; N = 4, *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001; wherein,

[0078] a is the overall appearance of wound repair;

[0079] b is the real - time semi - quantitative wound tracking analysis of wound regeneration;

[0080] c is the column chart of wound contraction over time;

[0081] d is the schematic diagram of H&E and Masson's trichrome staining of the located wound tissue after 6 days and 9 days.

[0082] Figure 13 Shows the commercial product Tegaderm, SIS patch and the asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ on the effect of vascularization on wound regeneration in a rat full - thickness wound model; N = 4, ***P ≤ 0.001; wherein,

[0083] a shows the VEGF (red) / DAPI (blue) immunofluorescence staining at 6 and 9 days after surgery;

[0084] b shows the semi - quantitative analysis of the VEGF fluorescence intensity expression based on Fig. a.

[0085] Figure 14 Shows the commercially available product Tegaderm, SIS patch and the asymmetric adhesive wound dressing SIS / PAA of Example 4 40％ / LAP 10％ Biocompatibility evaluation of three kinds of wound dressings; among them,

[0086] a shows the H&E staining diagrams of major organs including heart, liver, spleen, lung and kidney 9 days after implanting three kinds of wound dressings;

[0087] b shows the hematological analysis 9 days after implanting three kinds of wound dressings.

[0088] Figure 15 Shows the commercially available product Tegaderm, SIS patch and the asymmetric adhesive wound dressing SIS / PAA of Example 4 40％ / LAP 10％ Relevant schematic diagrams of wound repair of three kinds of wound dressings on the skin injury of Bama minipigs; N = 4, *P≤0.05, **P≤0.01, ***P≤0.001; among them,

[0089] a shows the experimental routine and pathological analysis description;

[0090] b shows the overall appearance of wound repair;

[0091] c shows the comparison of wound contraction over time;

[0092] d shows the comparison of epidermal thickness increase 12 days later;

[0093] e shows the H&E staining diagram of the located wound tissue 12 days later;

[0094] f shows the Masson's trichrome staining of the located wound tissue 12 days later.

[0095] Figure 16 Shows the commercially available product Tegaderm, SIS patch and the asymmetric adhesive wound dressing SIS / PAA of Example 4 40％ / LAP 10％ Relevant schematic diagrams of histological analysis of wound repair of three kinds of wound dressings on Bama minipigs; N = 4, *P≤0.05, **P≤0.01, ***P≤0.001; among them,

[0096] a is the immunofluorescence staining of TNF-α (red) / CD163 (green) / DAPI (blue) on the located wound tissue after 12 days;

[0097] b is the immunofluorescence staining of VEGF (red) / α-SMA (green) / DAPI (blue);

[0098] c is the semi-quantitative analysis of the fluorescence intensity expression of TNF-α / CD163 based on Figures a and b;

[0099] d is the semi-quantitative analysis of the fluorescence intensity expression of VEGF / α-SMA based on Figures a and b. Detailed implementation manners

[0100] The various exemplary embodiments, features and aspects of the present disclosure will be described in detail below. The special word "exemplary" here means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior or better than other embodiments.

[0101] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present disclosure can also be implemented without some specific details. In other instances, methods, means, equipment and steps well-known to those skilled in the art are not described in detail in order to highlight the gist of the present disclosure.

[0102] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values and numerical ranges appearing in the present disclosure should be understood to include the inevitable systematic errors in industrial production.

[0103] In this specification, the meaning expressed by using "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0104] In this specification, the so-called "some specific / preferred implementation manners", "other specific / preferred implementation manners", "implementation manners", etc. refer to the specific elements (for example, features, structures, properties and / or characteristics) related to the implementation manner described, which are included in at least one of the implementation manners described here, and may exist in other implementation manners or may not exist in other implementation manners. In addition, it should be understood that the elements can be combined in various implementation manners in any suitable manner.

[0105] In this specification, the numerical range expressed by using "numerical value A to numerical value B" refers to the range including the end point numerical values A and B.

[0106] In this specification, when using "normal temperature" and "room temperature", the temperature can be 15-25°C.

[0107] <First aspect>

[0108] A first aspect of the present disclosure provides an asymmetric adhesive wound dressing, which comprises:

[0109] a substrate having a fibril structure, and,

[0110] an adhesive layer including a first gel component and a second gel component, the first gel component being derived from an adhesive composition comprising an acrylic compound, a photoinitiator, a crosslinking agent, and a first solvent.

[0111] The asymmetric adhesive wound dressing of the present disclosure can not only firmly adhere to the injury, but also has good cell compatibility and angiogenesis-promoting ability, and can enable tissue regeneration, thereby producing a significant tissue repair effect.

[0112] <Substrate>

[0113] The substrate of the present disclosure is a substrate having a fibril structure. The present disclosure does not particularly limit the substrate, and some substrates commonly used in the art can be used. In the present disclosure, the substrate is derived from a biodegradable biomaterial, preferably a biomaterial mainly containing collagen, and the collagen can be of natural origin, synthetic, modified or crosslinked, including but not limited to submucosa, dermis, pericardium, collagen, gelatin, etc.

[0114] In some embodiments of the present disclosure, the substrate is derived from the small intestine submucosa, preferably from the acellular small intestine submucosa, that is, the substrate of the present disclosure can be prepared using the small intestine submucosa. In some embodiments of the present disclosure, the substrate is derived from the dermis, preferably from the acellular dermis, that is, the substrate of the present disclosure can be prepared using the dermis. In some embodiments of the present disclosure, the substrate is derived from the bladder submucosa, preferably from the acellular bladder submucosa, that is, the substrate of the present disclosure can be prepared using the bladder submucosa. In some embodiments of the present disclosure, the substrate is derived from the pericardium, preferably from the acellular pericardium, that is, the substrate of the present disclosure can be prepared using the pericardium. The submucosa (such as the small intestine submucosa), dermis, and pericardium, etc. are preferably derived from mammals, such as pigs, cows, sheep, dogs, cats, etc.

[0115] In one embodiment of the present disclosure, the substrate is derived from acellular porcine small intestinal submucosa. The porcine small intestinal submucosa can be commercially purchased. The source of porcine small intestinal submucosa is extensive, economically available, easy to process, and the acellular porcine small intestinal submucosa has excellent biocompatibility, is rich in collagen and growth factors, can induce cells to diffuse, adhere, grow and proliferate inward, and promote the repair and regeneration of its own tissue at the tissue defect site. It is suitable for use as the substrate for preparing the wound dressing of the present disclosure. Therefore, the present disclosure preferably uses the porcine small intestinal submucosa material substrate prepared from porcine small intestinal submucosa as the substrate.

[0116] Regarding the preparation method of the porcine small intestinal submucosa material substrate, the present disclosure does not make a special limitation, and it can be some common preparation methods in the art. Of course, the porcine small intestinal submucosa material substrate can also be commercially purchased. Preferably, the porcine small intestinal submucosa material substrate of the present disclosure can be prepared according to the preparation method in CN107007886A.

[0117] In another embodiment of the present disclosure, the substrate can also be a fiber membrane prepared from a chemical substance containing collagen. Regarding the fiber membrane, the present disclosure does not make a special limitation, and it can be a common fiber membrane in the art, such as: non-woven fiber membrane or spun fiber membrane, etc.

[0118] The non-woven fiber membrane of the present disclosure can be obtained by non-woven process using a chemical substance containing collagen and one or more combinations of optionally present other high molecular polymers or their derivatives. The spun fiber membrane of the present disclosure can be obtained by processes such as electrospinning technology, centrifugal spinning technology, hot melt spinning technology, and melt electrospinning technology using a chemical substance containing collagen and one or more combinations of optionally present other high molecular polymers or their derivatives.

[0119] Other high molecular polymers or their derivatives can be various common high molecular polymers or their derivatives in the art, such as one or more combinations selected from natural high molecular polymers. For example, the common high molecular polymers or their derivatives can be one or more combinations of cellulose, chondroitin sulfate, chitosan, modified chitosan, fibrin, silk protein, peptide polymer mimicking elastin, heparin, agar, dextran, alginic acid, cellulose, alginate, starch.

[0120] Preferably, in order to obtain an asymmetric sticky wound dressing with excellent properties in all aspects, the present disclosure preferably uses the porcine small intestinal submucosa material substrate. Based on the substrate of the present disclosure, the wound dressing of the present disclosure contains collagen fibers. Due to the presence of collagen fibers, the function of the asymmetric sticky wound dressing of the present disclosure can be better exerted.

[0121] <Adhesive layer>

[0122] The adhesive layer of the present disclosure has strong adhesion and can be used for the preparation of tissue repair products, especially for the preparation of skin injury repair products.

[0123] First gel component

[0124] The adhesive layer of the present disclosure includes a first gel component, which is derived from an adhesive composition, and the adhesive composition includes an acrylic compound, a photoinitiator, a crosslinking agent, and a first solvent.

[0125] In the present disclosure, due to the presence of active groups, such as carboxyl groups, in the acrylic compound, and the active groups can form tissue adhesion with the tissue surface through physical forces such as hydrogen bonds and electrostatic interactions in a short time. As the contact time prolongs, the active groups react with the amino groups on the tissue surface to undergo amidation reaction, forming chemical bonds to achieve tissue bonding.

[0126] In some specific embodiments, based on the total mass of the first solvent being 100%, the content of the acrylic compound is 10% - 60%, such as 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, etc. When the content of the acrylic compound is 10% - 60%, a first gel component can be formed, making the adhesive layer have excellent adhesion.

[0127] Specifically, the acrylic compound includes one or more combinations of acrylic acid, polyacrylamide, polyacrylic acid, and hydroxyethyl polymethacrylate, preferably acrylic acid and / or polyacrylic acid.

[0128] In the present disclosure, a photoinitiator refers to a compound that decomposes by irradiating active energy rays such as ultraviolet light or visible light to generate free radical species, cationic species, or anionic species. The present disclosure uses a photoinitiator so that the adhesive composition of the present disclosure can be cured under ultraviolet light conditions.

[0129] Based on the total mass of the first solvent being 100%, the content of the photoinitiator is 0.01% - 0.5%, such as 0.02%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, 0.28%, 0.3%, 0.32%, 0.35%, 0.38%, 0.4%, 0.42%, 0.45%, 0.48%, etc. When the content of the photoinitiator is 0.01% - 0.5%, the polymerization reaction can be effectively initiated, thereby obtaining the first gel component.

[0130] The photoinitiator includes ketone photoinitiators, preferably including one or more combinations of α-ketoglutaric acid, 2,2-dimethoxy-2-phenylacetophenone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and more preferably α-ketoglutaric acid.

[0131] Furthermore, the purpose of using a crosslinking agent in the present disclosure is to enable the polyacrylic acid compound formed by the polymerization of the acrylic acid compound to crosslink and form a water-insoluble gel layer. If no crosslinking agent is contained, since the polyacrylic acid compound is also a water-soluble polymer, it will be dissolved by water when contacting wet tissue, resulting in the loss of adhesion.

[0132] In order to effectively exert the function of the crosslinking agent, based on the total mass of the first solvent being 100%, the content of the crosslinking agent is 0.05% - 6%, such as 0.1%, 0.3%, 0.5, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, etc. When the content of the crosslinking agent is 0.05% - 6%, a desired gel layer can be formed.

[0133] Specifically, in the present disclosure, the crosslinking agent includes one or more combinations of gelatin methacrylate, hyaluronic acid methacrylate, polycaprolactone diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, N,N'-methylenebisacrylamide.

[0134] Furthermore, for the first solvent, the present disclosure is not particularly limited and can be an inorganic solvent commonly used in the art. In order to better form a gel and thus obtain a desired adhesive layer, the first solvent described in the present disclosure is water.

[0135] In addition, in the present disclosure, for every 100 cm 2 of the substrate (the area of one surface), the content of the acrylic acid compound in the adhesive layer used can be 100 mg - 600 mg.

[0136] Second gel component

[0137] In the present disclosure, the adhesive layer further includes a second gel component. Preferably, the second gel component is derived from a clay mineral containing magnesium, lithium, and silicon elements and a second solvent. By using the second gel component in the present disclosure, a double-network structure can be formed with the first gel component, thereby further improving the mechanical properties and tissue adhesion of the asymmetric adhesive wound dressing. When the second gel component is used, the asymmetric adhesive wound dressing obtained in the present disclosure has a better adhesion effect compared to existing wound dressings.

[0138] In some specific embodiments, the clay mineral is derived from laponite nanoparticles (LAP). The clay mineral in laponite nanoparticles contains magnesium, lithium, and silicon elements. When using the asymmetric adhesive wound dressing of the present disclosure, active elements such as magnesium and silicon elements can be released in the form of ions, which can effectively enhance cell migration and angiogenesis and have the potential for effective tissue repair in the field of soft tissue regeneration. Specifically, the particle size of the laponite nanoparticles is 5 - 50 nm, preferably 5 - 20 nm.

[0139] In the present disclosure, by adding a second solvent, the clay mineral can form a gel, which is beneficial for use. The second solvent is not particularly limited in the present disclosure and can be a commonly used inorganic solvent in the art, such as water.

[0140] Specifically, in the present disclosure, based on the total mass of the second solvent being 100%, the content of the clay mineral is 1 - 15%, such as 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, etc. When the content of the clay mineral is 1 - 15%, it is beneficial to form the second gel component, and the role of the clay mineral can be effectively exerted.

[0141] In some specific embodiments, the mass ratio of the clay mineral to the acrylic compound is 1:10 - 1:200, preferably 1:30 - 1:150, such as 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, 1:110, 1:120, 1:130, 1:140, 1:150, 1:160, 1:170, 1:180, 1:190, etc. When the mass ratio of the clay mineral to the acrylic compound is 1:10 - 1:200, there is a synergistic effect between the clay mineral and the acrylic compound, and the roles of both can be more effectively exerted.

[0142] In addition, when the second gel component is used, the asymmetric adhesive wound dressing of the present disclosure has good cell compatibility and angiogenesis activity for fibroblasts, etc. Applying the asymmetric adhesive wound dressing to the wound site, through Mg 2+ and Si4+ The release mechanism, etc., promotes significant regeneration of skin tissue at the wound site. This asymmetric adhesive wound dressing has broad application prospects in the fields of wound dressings, hernia repair patches, and cardiovascular stents.

[0143] In addition, in the present disclosure, for every 100 cm 2 of the substrate (the area of one surface), in the adhesive layer used, the content of clay minerals containing magnesium, lithium, and silicon elements can be 10 mg - 150 mg.

[0144] <Second aspect>

[0145] The second aspect of the present disclosure provides a method for preparing the asymmetric adhesive wound dressing according to the first aspect of the present disclosure, which includes the step of mixing the components of the adhesive layer and then compounding and molding with the substrate. The method for preparing the asymmetric adhesive wound dressing of the present disclosure is simple and easy to implement, the raw materials are easy to obtain, and it is suitable for mass production.

[0146] In some specific embodiments, the preparation method includes the following steps:

[0147] The step of obtaining the first gel component;

[0148] The step of obtaining the second gel component;

[0149] Mix the first gel component and the second gel component to obtain a mixed product;

[0150] Make the mixed product present on at least one surface of the substrate, and obtain an asymmetric adhesive wound dressing after a chemical reaction.

[0151] Specifically, in the present disclosure, the first gel component includes an acrylic pre-polymerization solution, and the acrylic pre-polymerization solution is prepared by dissolving an acrylic compound, a photoinitiator, and a cross-linking agent in a first solvent. The second gel component includes dissolving clay minerals containing magnesium, lithium, and silicon elements in a second solvent. Then, the first gel component and the second gel component are mixed to obtain a mixed product. At this time, some gels have been formed in the mixed product, mainly the gels formed by the second gel component.

[0152] Finally, make the mixed product present on at least one surface of the substrate, and obtain an asymmetric adhesive wound dressing after a chemical reaction. Specifically, the mixed product can be made to be present on at least one surface of the substrate by one or a combination of two or more of spreading, coating, casting, and spraying.

[0153] In some specific embodiments, the conditions for the chemical reaction include carrying out under the irradiation of ultraviolet light. The chemical reaction may include a polymerization reaction and a photocrosslinking reaction. Through the chemical reaction, not only can the acrylic compounds in the first gel component undergo a polymerization reaction, but also the physical crosslinked gel network structure of the first gel component and the chemical crosslinked gel network structure of the second gel component can form a double network structure, thereby enhancing the cohesive force and further improving the mechanical properties and tissue adhesion of the asymmetric adhesive wound dressing.

[0154] Preferably, the power of the ultraviolet light is 200 - 400W, such as: 220W, 250W, 280W, 300W, 320W, 350W, 380W, etc.; the wavelength is 350 - 400nm, such as: 360nm, 370nm, 380nm, 390nm, etc. When the power of the ultraviolet light is 200 - 400W and the wavelength is 350 - 400nm, both the polymerization reaction and the photocrosslinking reaction can proceed effectively.

[0155] <Third aspect>

[0156] As Figure 1 shown, the third aspect of the present disclosure provides a use of the asymmetric adhesive wound dressing according to the first aspect of the present disclosure for preparing tissue repair products, especially for preparing skin injury repair products, hernia repair patches, and cardiovascular stents.

[0157] Examples

[0158] The embodiments of the present disclosure will be described in detail below in conjunction with the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure. For those not specified in the examples, the operations are carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments not indicated by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0159] In the examples, acrylic acid (AA) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (China), laponite (LAP) nanoparticles were purchased from Macklin (China), gelatin methacrylate (Gel - MA) was purchased from Sigma (degree of methacrylation 50%), and the SIS patch was purchased from Beijing Bohui Ruijin Biotechnology Co., Ltd. Unless otherwise specified, other reagents were all of analytical grade and provided by Beijing Chemical Reagent Co., Ltd. (China).

[0160] 1. Related research on laponite nanoparticles

[0161] The morphology of laponite nanoparticles was detected using a transmission electron microscope (TEM) and an energy dispersive spectrometer (EDS), and the results are as Figure 2 shown.

[0162] From Figure 2 It can be seen that the average particle size of the saponite nanoparticles is about 10 nm. The elemental mapping images show that the saponite nanoparticles have specific elements such as Mg, Si, Na, and O.

[0163] 20 mg, 40 mg, 60 mg, 80 mg, and 100 mg of saponite nanoparticles were respectively placed in 1 ml of deionized water and ultrasonically dispersed for 5 minutes at a power of 300 W. Among them, based on the total mass of deionized water being 100%, the weight percentages of the saponite nanoparticles were 2%, 4%, 6%, 8%, and 10% respectively. Subsequently, an inverted centrifuge tube was used, and the gelation time was measured using the timing method. The results are as Figure 3 shown.

[0164] From Figure 3 It can be seen that when the concentration of saponite nanoparticles in water is low (such as 2% and 4%), the electrostatic interaction between the saponite nanoparticles is weak, resulting in difficulty in gel formation. As the concentration increases, gel formation becomes obvious, and the gelation time shortens as the concentration of the nanoparticles increases. When the concentration of the saponite nanoparticles reaches 10%, the gelation time drops to 86.75 ± 6.70 seconds.

[0165] 2. Research on polyacrylic acid gel

[0166] 1 g, 2 g, 3 g, and 4 g of acrylic acid and 100 mg of methacrylated gelatin were respectively dissolved in 10 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the contents of acrylic acid were 10%, 20%, 30%, and 40% respectively, and the content of methacrylated gelatin was 1%. Then, based on the total mass of deionized water being 100%, 0.2% of α-ketoglutaric acid was added as a photoinitiator. Then, a polymerization reaction and a photocrosslinking reaction were initiated under ultraviolet light (360 nm) at a power of 300 W for 30 minutes to obtain a polyacrylic acid gel, denoted as: PAA adhesive.

[0167] Tissue adhesion research was carried out on the polyacrylic acid gel. The shear adhesion strength test was carried out according to ASTM F2255. The pig skin was cut into 4 cm × 2.5 cm, and then the polyacrylic acid gel was placed on a piece of pig skin covering 2 cm × 2 cm. Then, the two pieces of pig skin were bonded in opposite directions at room temperature. After 1 hour, a universal testing machine was used to test the force-displacement curve in the shear direction at a speed of 5 mm / min. The shear adhesion strength (Pa) at the bonding site obtained using the pig skin was calculated as follows: F max (N) / S(m 2 ), where F max is the maximum shear force and S is the bonding area. The results are as Figure 4As shown

[0168] From Figure 4 It can be seen that as the concentration of acrylic acid increases, the shear adhesion strength increases correspondingly. When the content is 40%, the adhesive force reaches 23.59 ± 5.59 kPa.

[0169] Example 1

[0170] Dissolve 4 g of acrylic acid and 100 mg of methacrylated gelatin in 10 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the weight percentage of acrylic acid is 40%, and the content of methacrylated gelatin is 1%; then, based on the total mass of deionized water being 100%, add 0.2% of α-ketoglutaric acid as a photoinitiator to obtain an acrylic pre-polymerization solution.

[0171] Coat the acrylic pre-polymerization solution on one surface of a 100 cm 2 SIS patch, and initiate the polymerization reaction and photo-crosslinking reaction under ultraviolet light (360 nm) with a power of 300 W for 30 minutes to form an adhesive layer on the SIS patch, thereby obtaining an asymmetric sticky wound dressing, denoted as: SIS / PAA 40％ .

[0172] Example 2

[0173] Place 60 mg of laponite nanoparticles in 1 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the content of laponite nanoparticles is 6%; ultrasonically disperse for 5 minutes at a power of 300 W to obtain a laponite solution.

[0174] Dissolve 4 g of acrylic acid and 100 mg of methacrylated gelatin in 10 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the weight percentage of acrylic acid is 40%, and the content of methacrylated gelatin is 1%; then, based on the total mass of deionized water being 100%, add 0.2% of α-ketoglutaric acid as a photoinitiator to obtain an acrylic pre-polymerization solution.

[0175] Mix the acrylic pre-polymerization solution and the laponite solution to obtain a mixed product.

[0176] Coat the mixed product on the surface of a 100 cm 2 SIS patch, and initiate the polymerization reaction and photo-crosslinking reaction under ultraviolet light (360 nm) with a power of 300 W for 30 minutes to form an adhesive layer on the SIS patch, thereby obtaining an asymmetric sticky wound dressing, denoted as: SIS / PAA 40％ / LAP 6％ .

[0177] Example 3

[0178] 80 mg of laponite nanoparticles were placed in 1 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the mass percentage of laponite nanoparticles was 8%; ultrasonic dispersion was carried out for 5 minutes at a power of 300 W to obtain a laponite solution.

[0179] 4 g of acrylic acid and 100 mg of methacrylated gelatin were dissolved in 10 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the weight percentage of acrylic acid was 40%, and the content of methacrylated gelatin was 1%; then, based on the total mass of deionized water being 100%, 0.2% of α-ketoglutaric acid was added as a photoinitiator to obtain a pre-polymerized acrylic acid solution.

[0180] The pre-polymerized acrylic acid solution and the laponite solution were mixed to obtain a mixed product.

[0181] The mixed product was coated on the surface of a 100 cm 2 SIS patch. A polymerization reaction and a photo-crosslinking reaction were initiated under ultraviolet light (360 nm) with a power of 300 W for 30 minutes to form an adhesive layer on the SIS patch, thereby obtaining an asymmetric adhesive wound dressing, denoted as: SIS / PAA 40％ / LAP 8％ .

[0182] Example 4

[0183] As Figure 5 shown, 100 mg of laponite nanoparticles were placed in 1 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the mass percentage of laponite nanoparticles was 10%; ultrasonic dispersion was carried out for 5 minutes at a power of 300 W to obtain a laponite solution.

[0184] 4 g of acrylic acid and 100 mg of methacrylated gelatin were dissolved in 10 mL of deionized water. Among them, based on the total mass of deionized water being 100%, the weight percentage of acrylic acid was 40%, and the content of methacrylated gelatin was 1%; then, based on the total mass of deionized water being 100%, 0.2% of α-ketoglutaric acid was added as a photoinitiator to obtain a pre-polymerized acrylic acid solution.

[0185] The pre-polymerized acrylic acid solution and the laponite solution were mixed to obtain a mixed product.

[0186] The mixed product was coated on the surface of the SIS patch. A polymerization reaction and a photo-crosslinking reaction were initiated under ultraviolet light (360 nm) with a power of 300 W for 30 minutes to form an adhesive layer on the SIS patch, thereby obtaining an asymmetric adhesive wound dressing, denoted as: SIS / PAA 40％ / LAP 10％ , and the specific morphology is asFigure 5 and 6 as shown

[0187] Performance test

[0188] 1. Morphological Study of Asymmetric Adhesive Wound Dressings

[0189] Observe the appearance of the asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ in Example 4, and use a scanning electron microscope (SEM) (Hitachi S4800, Japan) to observe the morphological structure of the surface and cross-section of the asymmetric adhesive wound dressing, and use an energy dispersive spectrometer (EDS) to characterize the element distribution. The results are as Figure 5 and Figure 6 shown

[0190] It can be seen from Figure 5 and 6 that among them, Figure 6 a is a schematic process diagram for preparing the asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ in Example 4, which includes coating the surface of the SIS patch with a mixed product of a lithium saponite solution and an acrylic prepolymerization solution, and then placing it under ultraviolet light irradiation. After polymerization and photocrosslinking reactions, SIS / PAA 40％ / LAP 10％ is formed Figure 6 b shows the physical appearance of the SIS / PAA 40％ / LAP 10％ patch, indicating that the adhesive layer adheres to the SIS surface without affecting the morphology of the patch, and SIS / PAA 40％ / LAP 10％ exhibits good flexibility ( Figure 6 c). The scanning electron microscope (SEM) image of SIS / PAA 40％ / LAP 10％ shows that the adhesive layer adheres evenly to the surface of the SIS patch ( Figure 5 , Figure 6 d).

[0191] In addition, the element mapping diagrams (such as Mg element and Si element) of SIS / PAA 40％ / LAP 10％ confirm the uniform distribution of lithium saponite within SIS / PAA 40％ / LAP 10％ ( Figure 6 e).

[0192] 2. Mechanical Study

[0193] The SIS patch, the asymmetric adhesive wound dressing SIS / PAA of Example 1 40％ and the asymmetric adhesive wound dressing SIS / PAA of Example 4 40％ / LAP 10％ were cut into regular pieces (3 cm in length and 1 cm in width), and then loaded onto a universal testing machine (Instron 5848, China) for mechanical property testing. The test was carried out at room temperature at a tensile speed of 10 mm·min -1 . The stress-strain curve was measured, and the ultimate tensile strength (UTS) corresponded to the maximum tension at the elongation at break. The Young's modulus was determined by the slope of the stress-strain curve in the elastic deformation region, and the results are as Figure 7 shown.

[0194] It can be seen from Figure 7 that the introduction of SIS / PAA 40％ and SIS / PAA 40％ / LAP 10％ improved the mechanical strength. Compared with the SIS patch and SIS / PAA 40％ / LAP 10％ , the Young's modulus and tensile strength increased from 215.15 ± 13.90 MPa and 17.56 ± 3.82 MPa to 360.63 ± 24.37 MPa and 48.90 ± 6.80 MPa, respectively. Therefore, the asymmetric adhesive wound dressing structure of the present disclosure exhibits excellent mechanical strength.

[0195] 3. Research on tissue adhesion and bursting strength

[0196] The asymmetric adhesive wound dressing SIS / PAA 40％ / LAP 10％ of Example 4 was used to adhere to different tissues, and the results are as Figure 8 shown.

[0197] The tissue adhesion of the asymmetric adhesive wound dressings of Examples 1-4 and commercial tissue adhesive products was studied.

[0198] The shear adhesion strength test was carried out according to ASTM F2255. The porcine skin was cut into 4 cm × 2.5 cm, and then the asymmetric adhesive wound dressing was placed on a piece of porcine skin covering 2 cm × 2 cm, and then the two pieces of porcine skin were bonded in opposite directions at room temperature. After 1 hour, the force-displacement curve in the shear direction was tested using a universal testing machine at a speed of 5 mm / min. The shear adhesion strength (Pa) at the bonding site obtained using porcine skin was calculated as follows: F max (N) / S(m 2 ), where F max is the maximum shear force and S is the bonding area, and the results are as Figure 9 shown.

[0199] The bursting strength test was carried out according to ASTM F2392. A 5-mm defect was created on 3-cm porcine colon by biopsy, and then the material (2 cm × 2 cm) was placed at room temperature to cover the defect for 15 minutes. The pressure pump applied pressure at 2 mL·min -1 and the bursting strength when leakage occurred was recorded. The results are as Figure 9 shown.

[0200] As Figure 8 can be seen, the asymmetric adhesive wound dressing structure of the present disclosure also exhibits tissue adhesion strength.

[0201] As Figure 9 can be seen, in the tissue shear adhesion test, when the mass percentage of laponite reached 10%, the shear adhesion strength increased significantly, rising from the initial value of 21.38 ± 4.94 kPa (SIS / PAA 40％ ) to 32.98 ± 2.31 kPa (SIS / PAA 40％ / LAP 10％ )( Figure 9 (a, b)). In addition, the shear adhesion strength of the prepared SIS / PAA 40％ / LAP 10％ was compared with that of commercial tissue adhesive products, demonstrating that its shear adhesion strength exceeded products such as Coseal (22.05 ± 1.65 kPa), TissuePatch (20.70 ± 2.12 kPa), and Tegaderm (7.25 ± 2.08 kPa)( Figure 9 c).

[0202] In addition, the bursting strength was also tested according to the ASTM F2392 standard. The bursting strength of SIS / PAA 40％ / LAP 10％ was 22.25 ± 2.50 kPa, which was significantly higher than that of Coseal (7.53 ± 1.22 kPa), TissuePatch (6.10 ± 0.62 kPa), and Tegaderm (2.50 ± 0.95 kPa)( Figure 9 (d, e)). This is because the combination of the double-network structure including the electrostatic interaction of laponite and the chemical crosslinking of polyacrylic acid significantly enhanced the mechanical strength and shear adhesion strength of the material( Figure 9 f). Therefore, the asymmetric adhesive wound dressing of the present disclosure exhibits excellent tissue adhesion, can promote wound closure, and prevent problems such as the dressing falling off from the wound site.

[0203] 4. Cell Compatibility and Angiogenesis Studies

[0204] Following the ISO 10993 biological test standard, the asymmetric adhesive wound dressings SIS / PAA based on Example 1 and Example 4 40％ and SIS / PAA 40％ / LAP 10％ as well as the SIS patch were respectively immersed in cell culture medium at a ratio of 6 cm 2 ·mL -1 . After immersion for 24 hours, extracts were obtained, and a blank control group was set up.

[0205] The obtained extracts were co-cultured with fibroblasts L929 (48-well plate, 1000 cells in each well), and the co-culture was maintained for 1, 2, and 3 days. Cell viability was evaluated at 450 nm using the CCK-8 reagent in a microplate reader (Bio-Rad 680, USA), and live / dead cells stained with calcein-AM / PI fluorescent dye (Aladdin, China) were observed under a confocal laser scanning microscope (CLSM, TCS SP8, Leica, Germany), and the results were as Figure 10 shown.

[0206] To evaluate the angiogenesis potential of the extracts, human umbilical vein endothelial cells HUVEC were used. 5,000 HUVEC were seeded into a 48-well plate and incubated with the extracts for 7 days, and a blank control group was set up. The culture medium was renewed every other day. After incubation, the human umbilical vein endothelial cells were stained with VEGF primary antibody (ab 32152, Abcam, UK), FITC-labeled F-actin, and fluorescent secondary antibody, and then incubated in the dark for 30 minutes. The expression of VEGF intracellularly was observed under a laser scanning confocal microscope (CLSM). Semi-quantitative analysis of the fluorescence intensity was performed using Image Pro Plus software, and the results were as Figure 11 shown.

[0207] Basement membrane matrix Matrigel (Corning, USA) was used to prepare the matrix for cell seeding in the cell culture plate. The seeding density was 5,000 HUVEC, and they were incubated with the extracts for 12 hours, and a blank control group was set up. The formation of tubular networks was observed under an optical microscope. The spacing between the networks was semi-quantitatively measured using Image J software.

[0208] This disclosure immersed the SIS patch, the asymmetric adhesive wound dressing SIS / PAA of Example 1 40％ and the asymmetric adhesive wound dressing SIS / PAA of Example 4 40％ / LAP 10％ in cell culture medium for 24 hours for cytotoxicity evaluation. Then the obtained extraction medium was used to evaluate the cytotoxicity to L929 cells and HUVEC( Figure 11 a).

[0209] The results of co - culture with L929 cells showed that SIS / PAA 40％ / LAP 10％ group presented a spindle - shaped cell morphology, indicating that it did not induce obvious cytotoxicity. In addition, with the extension of the culture time (up to 3 days), cell proliferation was observed, indicating that the extraction medium had good cell compatibility( Figure 10 (a,b)).

[0210] Next, cell scratch, angiogenesis, and angiogenic differentiation assays were performed on HUVEC. SIS / PAA 40％ / LAP 10％ group significantly promoted the migration of HUVEC, and the migration rate was about 4.86 times that of the control group( Figure 11 (b,c)). In addition, it was observed that the SIS patch had a certain role in promoting cell migration, which might be due to the presence of residual bioactive components such as TGF - β in the material.

[0211] In the angiogenesis experiment, SIS / PAA 40％ / LAP 10％ showed a denser number of tubes, number of connection points, and longer tube length (~278μm), while the control group had a tube length of only ~50μm and the SIS group had a tube length of ~133μm( Figure 11 (d,e)). Immunofluorescence staining showed that the expression of VEGF in the control group was low, while the expression of VEGF in the SIS / PAA 40％ / LAP 10％ group was about 3 times higher than that in the control group( Figure 11 (f,g)). These results indicated that the released bioactive ions such as Mg 40％ / LAP 10％ and Si 2+ and Si 4+ could effectively enhance cell migration and angiogenesis, indicating its potential for effective tissue repair in the field of soft tissue regeneration.

[0212] 5. Study on the full - thickness wound model of rats

[0213] All animal experiments complied with the Tianjin Medical Laboratory Animal Management Regulations, and the animal protocol was approved by the Institutional Animal Care and Use Committee of Yishengyuan Gene Technology (Tianjin) Co., Ltd. (No.: YSY - DWLL - 2023227).

[0214] After SD rats were anesthetized with isoflurane, a 10 - mm biopsy punch was used to create a full - thickness skin defect on the back of SD rats, and then the animal models were divided into four groups. 1) Without further treatment, the wound was left (control group). 2) Tegaderm TMCover the wound (Tegaderm group). 3) Cover the wound with SIS patch (SIS group). 4) Cover the wound with SIS / PAA 40％ / LAP 10％ covering the wound (SIS / PAA 40％ / LAP 10％ group).

[0215] After implanting the above four groups of wound dressings respectively, fix the implanted wound dressings and cover them with sterile bandages to prevent the implants from falling off or separating from the wound. All implanted wound dressings were changed every two days and then standard care was carried out. At 3, 6, and 9 days after surgery, the gross appearance of wound regeneration was evaluated. Among them, the harvested targeted tissues were fixed with 10% formalin and sectioned for H&E staining, Masson's trichrome staining, and VEGF / DAPI (ab32152, Abcam) immunohistochemical staining. The section scanning images were obtained using a digital slide scanning device (Nanozoomer, Hamamatsu, Japan), and the results are as Figure 12 shown.

[0216] In a full-thickness skin injury model of rats, we first created a circular defect with a diameter of 10 mm on the back of anesthetized rats. Place different wound dressings (Tegaderm group, SIS group, and SIS / PAA 40％ / LAP 10％ group) on the wound surface and change the wound dressings every other day according to the standard care procedure. After macroscopic evaluation of wound healing, the wound repair effects of the control group and the Tegaderm group were poor, and the wounds were still obvious after 9 days.

[0217] There was a certain degree of wound repair in the SIS group on the 9th day, while most of the wounds in the SIS / PAA 40％ / LAP 10％ group had recovered ( Figure 12 a), and a similar tissue repair rate could be seen in the semi-quantitative wound tracking analysis ( Figure 12 b)). Statistically, the wound contraction rate on the 6th day after surgery was 15.45±2.60% in the control group, 23.88±3.35% in the Tegaderm group, 43.28±4.79% in the SIS group, and 55.70±4.42% in the SIS / PAA 40％ / LAP 10％ group. On the 9th day, the wound contraction rate in the control group was 44.20±5.75%, 53.40±8.17% in the Tegaderm group, 76.10±5.78% in the SIS group, and 94.58±4.54% in the SIS / PAA 40％ / LAP 10％ group ( Figure 12 c).

[0218] Combined with the previous cell results ( Figure 11 ), we speculate that the SIS patch contains endogenous growth factors and other active substances, such as VEGF and TGF-β, and that SIS / PAA 40％ / LAP 10％ can adhere firmly to the wound surface. In addition, when the laponite nanoparticles are penetrated by body fluids, they can release bioactive ions, such as Mg 2+ and Si 4+ , thus promoting tissue healing.

[0219] Histological staining on days 6 and 9 showed that the control group and the Tegaderm group had obvious wound defects and lower collagen expression. In contrast, the wound gaps in the SIS group, especially the SIS / PAA 40％ / LAP 10％ group became narrower and the collagen maturity was higher ( Figure 12 d). In addition, in the VEGF / DAPI fluorescence staining, the SIS / PAA 40％ / LAP 10％ group showed higher VEGF fluorescence intensity, which was 1.84 times and 2.89 times that of the control group on days 6 and 9, respectively ( Figure 13 ). These results indicate that SIS / PAA 40％ / LAP 10％ can adhere firmly to the wound surface and, with the release of active ions by LAP, achieve excellent tissue repair effects.

[0220] On the 9th day after surgery, pathological H&E staining of the main metabolic organs such as the heart, liver, spleen, lungs, and kidneys showed that there were no significant differences in the tissue morphology and hematological analysis between the SIS / PAA 40％ / LAP 10％ group and the control group, indicating good tissue compatibility ( Figure 14 ).

[0221] 6. Wound model in Bama minipigs

[0222] All animal experiments complied with the Tianjin Regulations on the Administration of Laboratory Animals, and the animal protocol was approved by the Institutional Animal Care and Use Committee of Yishengyuan Gene Technology (Tianjin) Co., Ltd. (No. YSY-DWLL-2023228).

[0223] After two pigs were anesthetized with isoflurane, 20-mm biopsy punch holes were made on the pig's back to create skin defects, and then the animal models were divided into four groups. 1) No further treatment, leaving the wound (control group). 2) Covering the wound with Tegaderm TM (Tegaderm group). 3) Covering the wound with the SIS patch (SIS group). 4) Covering the wound with SIS / PAA40％ / LAP 10％ Cover the wound (SIS / PAA 40％ / LAP 10％ group).

[0224] After implanting four groups of wound dressings respectively, fix the implanted wound dressings and cover them with sterile bandages to prevent the implants from falling off or separating from the wound. All implanted wound dressings are changed every two days, and then standard care is carried out. On the 3rd, 6th, 9th, and 12th days after surgery, the gross appearance of wound regeneration is evaluated. Among them, the harvested targeted tissues are fixed with 10% formalin and sectioned for H&E staining, Masson's trichrome staining, and immunohistochemical staining of TNF-α / CD163 / DAPI (MA5-44021, ThermoFisher; EPR19518, Abcam) and VEGF / α-SMA / DAPI (ab2350, Abcam; MA1-06110, ThermoFisher). The section scanning images are obtained using a digital slide scanning device (Nanozoomer, Hamamatsu, Japan).

[0225] In a larger-scale wound defect model of minipig skin, the effectiveness of the wound dressing in promoting tissue healing was evaluated ( Figure 15 a).

[0226] In the overall wound repair results, the early wound repair speed of each group was slow, but after 9 days, the wound repair results were different. On the 9th day after surgery, the wound contraction rate of the SIS / PAA 40％ / LAP 10％ group was 40.02 ± 8.76%, significantly higher than that of other groups. On the 12th day, the wound contraction rate of the SIS / PAA 40％ / LAP 10％ group reached 80.75 ± 9.53%, while the contraction rates of the control group, Tegaderm group, and SIS group were only 37.25 ± 3.77%, 46.50 ± 5.26%, and 55.50 ± 5.80% respectively ( Figure 15 (b, c)). In histological staining, we observed that the SIS / PAA 40％ / LAP 10％ wound dressing used on the wound surface did not cause adverse reactions.

[0227] In addition, compared with the control group and Tegaderm group, using the SIS group and SIS / PAA 40％ / LAP 10％ group resulted in a significant increase in the thickness of the epidermal layer (SIS group: 135.63 ± 40.86 μm, SIS / PAA 40％ / LAP 10％Group: (271.75 ± 12.84 μm). In Masson's trichrome staining, SIS / PAA 40％ / LAP 10％ group showed a higher level of collagen expression and more ordered collagen arrangement ( Figure 15 (d-f)). These results confirmed that SIS / PAA 40％ / LAP 10％ had good biocompatibility, which could not only effectively promote the repair of full-thickness skin wounds in rats, but also achieved excellent tissue repair effects in a larger-scale skin injury model of minipigs.

[0228] In addition, we performed immunohistochemical staining on the wound tissues at 12 days to further analyze how the asymmetric adhesive wound dressing improved tissue repair.

[0229] We selected TNF-α as a typical pro-inflammatory marker and CD163 as a typical anti-inflammatory marker. According to the expression of TNF-α / CD163 immunofluorescence, there was no significant difference in TNF-α expression among groups. However, the expression of CD163 in the SIS / PAA 40％ / LAP 10％ group was 1.31 times that of the control, 1.28 times that of the Tegaderm group, and 1.14 times that of the SIS group ( Figure 16 (a,c)).

[0230] In terms of VEGF / α-SMA expression, the SIS / PAA 40％ / LAP 10％ group showed higher VEGF and α-SMA expression levels compared with other groups. The expression of VEGF in the SIS / PAA 40％ / LAP 10％ group was 2.75 times that of the control group and 2.79 times that of the Tegaderm group; the expression of α-SMA in the SIS / PAA 40％ / LAP 10％ group was 2.99 times that of the control group, 3.36 times that of the Tegaderm group, and 1.41 times that of the SIS group ( Figure 16 (b,d)).

[0231] These results indicate that there is a significant inflammatory response in the early stage of wound healing. When SIS / PAA 40％ / LAP 10％ is used as a wound dressing, the release of bioactive ions such as Mg 2+ and Si 4+ increases the expression level of the anti-inflammatory factor between cells (such as CD163) to create a microenvironment conducive to cell migration and proliferation. In addition, Mg 2+ and Si4+ can significantly promote angiogenesis in tissues. Therefore, SIS / PAA 40％ / LAP 10％ can achieve excellent tissue wound repair effects.

[0232] In all the above experimental tests, all quantitative data are expressed as mean ± standard deviation (SD). Statistical analysis was performed using SPSS software by one-way analysis of variance (ANOVA). Inter-group differences with *p < 0.05 were considered statistically significant, **p < 0.01 were considered highly significant. ***p < 0.001 were considered very significant.

[0233] In the present disclosure, the asymmetric adhesive wound dressing exhibits excellent tissue adhesion strength (~33 kPa) and burst strength (~22 kPa), which are superior to those of commercially available tissue adhesives used as wound dressings. In cell experiments, rat and pig skin injury models, the asymmetric adhesive wound dressing exhibits good cell compatibility and angiogenesis-promoting ability, thereby producing significant tissue repair effects. This asymmetric adhesive wound dressing not only shows the advantages as a wound dressing, but also has the potential to be applied in surgical fields such as general surgery and cardiac surgery.

[0234] It should be noted that although the technical solutions of the present disclosure are introduced by specific examples, those skilled in the art can understand that the present disclosure should not be limited thereto.

[0235] The embodiments of the present disclosure have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An asymmetric adhesive wound dressing, characterized in that, Comprising: A substrate having a fibril structure, and An adhesive layer comprising a first gel component and a second gel component, the first gel component being derived from an adhesive composition comprising an acrylic compound, a photoinitiator, a crosslinking agent, and a first solvent.

2. The asymmetric adhesive wound dressing according to claim 1, characterized in that, Based on the total mass of the first solvent being 100%, the content of the acrylic compound is 10% - 60%, the content of the photoinitiator is 0.01% - 0.5%, and the content of the crosslinking agent is 0.05% - 6%.

3. The asymmetric adhesive wound dressing according to claim 1 or 2, characterized in that, The acrylic compound includes one or more combinations of acrylic acid, polyacrylamide, polyacrylic acid, hydroxyethyl polymethacrylate; and / or The crosslinking agent includes one or more combinations of gelatin methacrylate, hyaluronic acid methacrylate, polycaprolactone diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, N,N'-methylenebisacrylamide; and / or The photoinitiator includes a ketone photoinitiator, preferably including one or more combinations of α-ketoglutaric acid, 2,2-dimethoxy-2-phenylacetophenone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, 2-hydroxy-2-methyl-1-phenyl-1-propanone.

4. The asymmetric adhesive wound dressing according to any one of claims 1-3, characterized in that, The second gel component is derived from a clay mineral containing magnesium, lithium, and silicon elements and a second solvent; Preferably, the clay mineral includes laponite nanoparticles; More preferably, the particle size of the laponite nanoparticles is 5 - 50 nm, preferably 5 - 20 nm.

5. The asymmetric adhesive wound dressing according to claim 4, characterized in that, Based on the total mass of the second solvent being 100%, the content of the clay mineral is 1 - 15%.

6. The asymmetric adhesive wound dressing according to claim 4 or 5, characterized in that, The mass ratio of the clay mineral to the acrylic compound is 1:10 - 1:200, preferably 1:30 - 1:

150.

7. A method for preparing an asymmetric adhesive wound dressing according to any one of claims 1-6, characterized in that, Including the step of mixing the components of the adhesive layer and then compounding and molding with the substrate; Preferably, the preparation method includes the following steps: The step of obtaining the first gel component; The step of obtaining the second gel component; Mixing the first gel component and the second gel component to obtain a mixed product; Allowing the mixed product to be present on at least one surface of the substrate and obtaining an asymmetric adhesive wound dressing after a chemical reaction.

8. The preparation method according to claim 7, characterized in that, The first gel component includes an acrylic acid pre-polymerization solution prepared by dissolving an acrylic compound, a photoinitiator, and a crosslinking agent in a first solvent; and / or The second gel component includes a solution obtained by dissolving a clay mineral containing magnesium, lithium, and silicon elements in a second solvent.

9. The preparation method according to claim 7 or 8, characterized in that, The conditions of the chemical reaction include being carried out under the irradiation of ultraviolet light; preferably, the power of the ultraviolet light is 200 - 400 W and the wavelength is 350 - 400 nm.

10. Use of an asymmetric adhesive wound dressing according to any one of claims 1-6 for the preparation of tissue repair products, in particular for the preparation of skin injury repair products, hernia repair patches and cardiovascular stents.

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