Chronic ulcer wound repair gel as well as preparation method and application thereof

Abstract

The invention discloses chronic ulcer wound repair gel as well as a preparation method and application thereof, and belongs to the technical field of medical materials. The bacterial cellulose has the advantages of good biocompatibility, high water holding and moisturizing capacity, strong mechanical property, good air permeability, low toxicity and the like, so that the bacterial cellulose-based chronic ulcer wound repair gel capable of promoting chronic wound healing is prepared by compounding functional components by utilizing the material advantages of the bacterial cellulose. The gel can bidirectionally adjust the wet balance of the wound surface; a large amount of hydroxyl groups are contained, so that high water retention can be achieved, the ice-cold feeling is achieved, pain is effectively relieved, stimulation to wounds and mucous membranes is relieved, sensitivity of exposed nerves is relieved, and pain is relieved; the photosensitizer in the gel can inhibit bacterial infection through irradiation of near-infrared laser, and the active ingredients can inhibit inflammation diffusion, promote collagen deposition, angiogenesis and the like to promote healing of chronic ulcer wounds.

Description

Technical Field

[0001] The invention belongs to the technical field of medical materials, and in particular relates to a chronic ulcer wound repair gel and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] In recent years, the trend of population aging has become increasingly obvious. The aging population will increase the demand for residents' medical care, and the problem of pressure ulcers caused by long-term bed rest in the elderly must be taken seriously. Pressure ulcers, also known as bedsores, are caused by impaired blood supply and tissue malnutrition due to long-term pressure, friction or shear. This type of ulcer is common in patients with limited mobility, paralysis of sensory perception or coma, who can neither perceive nor respond to the need for regular repositioning of the body. When tissue compression exceeds capillary pressure, prolonged pressure or shear will cause ischemia. Skin necrosis is caused by tissue hypoxia and ischemia-reperfusion injury. The skin on bony protrusions such as the sacrum, hips and ankles is particularly susceptible to damage, which usually occurs after two hours of inactivity. The presence of inflammatory cytokines, excessive levels of reactive oxygen free radicals (ROS) and repeated bacterial infections are all key factors that lead to the development of skin injuries into chronic wounds.

[0004] With the continuous development of biomedical materials and the deepening of wound healing theory research, researchers have found that gel dressings that can provide a moist environment for the wound surface are considered to be ideal dressings for the treatment of chronic wounds. The high water content of the gel dressing keeps the granulation tissue and epithelial tissue in a moist environment. Its soft texture and low interfacial tension give it good biocompatibility and non-irritation, and help reduce the inflammatory response in the adjacent area. The gel dressing is soft and elastic. After the wound heals, it does not adhere to the new tissue and is easy to remove without causing any discomfort to the patient. The gel dressing can also reduce the temperature of the skin wound, thereby reducing pain. Antibacterial gel dressings, especially antibacterial agent-loaded sustained-release gel dressings, are increasingly widely used in the medical field, but they still have certain limitations. For example, the adhesion ability to the wound is poor and it is easy to fall off; it cannot fully reduce the concentration of active oxygen free radicals at the wound; the antibacterial property is not enough, or some antibacterial ingredients have strong antibacterial properties but still have certain cell or tissue organ toxicity. How to enhance the antibacterial properties of gel dressings, reduce their cytotoxicity, reduce the content of reactive oxygen free radicals at the wound site, and solve the problem of inflammation at the wound site are all development directions for dressings for the treatment of chronic wounds. Summary of the invention

[0005] In order to address the deficiencies in the prior art, the purpose of the present invention is to provide a chronic ulcer wound repair gel and a preparation method and application thereof. The present invention addresses the difficulties in the care and treatment of chronic infected wounds and provides a chronic ulcer wound repair gel that has excellent biocompatibility, high water retention and moisture retention capacity, strong mechanical properties, good air permeability and low toxicity, and can promote chronic wound healing.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] The first aspect of the present invention provides a chronic ulcer wound repair gel, comprising a bacterial cellulose hydrogel, and a functional component composited on the bacterial cellulose hydrogel;

[0008] The functional component is prepared by mixing glycerol, a suspension stabilizer, beta-glucan, epigallocatechin-3-gallate, epsilon-polylysine and a photosensitizer.

[0009] The second aspect of the present invention provides a method for preparing the above-mentioned chronic ulcer wound repair gel, comprising:

[0010] Adding bacterial cellulose into water to obtain bacterial cellulose microfiber suspension;

[0011] dissolving glycerol, a suspension stabilizer, β-glucan, epigallocatechin-3-gallate and ε-polylysine in water to obtain a composite solution;

[0012] Mixing the bacterial cellulose microfiber suspension with the composite solution to obtain a bacterial cellulose-based gel;

[0013] A photosensitizer is added to the bacterial cellulose-based gel, and the mixture is stirred to obtain a chronic ulcer wound repair gel.

[0014] The third aspect of the present invention provides a use of the chronic ulcer wound repair gel or the chronic ulcer wound repair gel prepared by the above preparation method in the preparation of wound dressings.

[0015] A fourth aspect of the present invention provides a wound dressing, comprising the chronic ulcer wound repair gel described above or the chronic ulcer wound repair gel prepared by the above preparation method.

[0016] The beneficial effects of the present invention are:

[0017] The present invention provides a chronic ulcer wound repair gel for the difficulties in the care and treatment of chronic wounds. Since bacterial cellulose has the advantages of good biocompatibility, high water-holding and moisture-retaining capacity, strong mechanical properties, good air permeability and low toxicity, the material advantages of bacterial cellulose are utilized, and its composite functional components are prepared to promote the healing of chronic wounds. The gel contains a large amount of water, which can discharge water to the wound surface to moisturize the over-dried wound surface, and at the same time has liquid affinity, can absorb wound exudate, and bidirectionally regulate the moisture balance of the wound surface. In addition, the gel contains a large amount of hydroxyl groups, highly holds water, has a cool feeling, and can effectively relieve pain. At the same time, the gel state of bacterial cellulose can reduce the stimulation to the wound and mucosa, reduce the sensitivity of exposed nerves, and relieve pain. In addition, the photosensitizer in the gel can inhibit bacterial infection through the irradiation of near-infrared laser, and the active ingredient can inhibit the spread of inflammation, and promote the healing of chronic ulcer wounds by promoting collagen deposition and angiogenesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 The morphological characterization diagram of the chronic ulcer wound repair gel prepared in Example 1 of the present invention; wherein A is a visual appearance diagram, and B is an electron microscope observation diagram;

[0020] Figure 2 The fibroblast culture test results of the chronic ulcer wound repair gel prepared in Example 1 of the present invention; wherein A is a physical picture of the chronic ulcer wound repair gel applied on the 3M skin-like tape, and B is a scanning electron microscope picture after co-culture;

[0021] Figure 3 The anti-inflammatory effect diagram of the chronic ulcer wound repair gel prepared in Example 1 of the present invention; wherein A, B, and C are the pathological results of skin damage repair detection under a light microscope on days 3, 7, and 15 of the control group, respectively, and D, E, and F are the pathological results of skin damage repair detection under a light microscope on days 3, 7, and 15 of the chronic ulcer wound repair gel group, respectively, and the scale bar = 100 μm;

[0022] Figure 4 The graph is a graph showing the antibacterial performance test results of the chronic ulcer wound repair gel prepared in Example 1 of the present invention; wherein A is a graph showing the antibacterial ring against Escherichia coli, and B is a graph showing the antibacterial ring against Staphylococcus aureus;

[0023] Figure 5 The moisturizing property of the chronic ulcer wound repair gel prepared in Example 1 of the present invention;

[0024] Figure 6 The actual pictures of the chronic ulcer wound repair gel prepared in Example 1 (B) of the present invention and Comparative Example 1 (A);

[0025] Figure 7 The moisturizing property of the chronic ulcer wound repair gel prepared in Comparative Example 1 of the present invention;

[0026] Figure 8 Comparison of the effects of the chronic ulcer wound repair gels prepared in Example 1, Comparative Example 3, Comparative Example 4 and Comparative Example 5 of the present invention on repairing chronic ulcer wounds;

[0027] Fig. 9 This is an evaluation of the sustained-release performance of the chronic ulcer wound repair gel prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0028] In view of the difficulties in the care and treatment of existing chronic infected wounds (the presence of inflammatory cytokines at the wound, excessive levels of reactive oxygen free radicals (ROS), and repeated bacterial infections, which lead to the development of skin damage into chronic wounds), the present invention proposes a chronic ulcer wound repair gel and its preparation method and application.

[0029] A first typical embodiment of the present invention provides a chronic ulcer wound repair gel, comprising a bacterial cellulose hydrogel, and a functional component composited on the bacterial cellulose hydrogel;

[0030] The functional component is prepared by mixing glycerol, a suspension stabilizer, beta-glucan, epigallocatechin-3-gallate, epsilon-polylysine and a photosensitizer.

[0031] The presence of inflammatory cytokines, excessive levels of reactive oxygen free radicals (ROS), and repeated bacterial infections are all key factors that lead to the development of skin injuries into chronic wounds. The present invention provides a chronic ulcer wound repair gel to address the difficulties in the care and treatment of chronic wounds. Since bacterial cellulose has the advantages of good biocompatibility, high water retention and moisture retention capacity, strong mechanical properties, good air permeability and low toxicity, the material advantages of bacterial cellulose are utilized and its functional components are compounded to prepare a bacterial cellulose-based chronic ulcer wound repair gel (hereinafter referred to as BC composite gel) that can promote the healing of chronic wounds.

[0032] BC composite gel contains a large amount of water, which can discharge water to the wound surface to moisturize the over-dry wound surface. At the same time, it has liquid affinity and can absorb wound exudate, bidirectionally regulating the moisture balance of the wound surface. In addition, BC composite gel contains a large amount of hydroxyl groups, highly retains water, has a cool feeling, and can effectively relieve pain. At the same time, the gel state of bacterial cellulose can reduce irritation to wounds and mucous membranes, reduce the sensitivity of exposed nerves, and relieve pain. In addition, the photosensitizer in BC composite gel can inhibit bacterial infection through near-infrared laser irradiation, and the active ingredients can inhibit the spread of inflammation, promote collagen deposition and angiogenesis, and promote the healing of chronic ulcer wounds.

[0033] In some examples of this embodiment, the suspension stabilizer is carboxymethyl cellulose.

[0034] In some examples of this embodiment, the molecular weight of the ε-polylysine is 3600-4300.

[0035] In some examples of this embodiment, the photosensitizer is toluidine blue.

[0036] Specifically, the functions of the components of the chronic ulcer wound repair gel provided by the present invention are as follows:

[0037] Bacterial cellulose (BC): The present invention uses bacterial cellulose as raw material to make bacterial cellulose into bacterial cellulose microfibers. The sustained release rate of the components in the gel is controlled by controlling the different lengths of the microfibers. Using bacterial cellulose microfibers as raw materials, bacterial cellulose itself contains a large amount of water, which can discharge water to the wound surface to moisturize the over-dry wound surface. At the same time, it has liquid affinity and can absorb wound exudate to bidirectionally regulate the moisture balance of the wound surface. In addition, the BC composite gel contains a large amount of hydroxyl groups, is highly water-retaining, has a cool feeling, and can effectively relieve pain. The gel state of the bacterial cellulose film can reduce irritation to wounds and mucous membranes, reduce the sensitivity of exposed nerves, and relieve pain. At the same time, the microfibers can be assembled into a network porous structure in the gel again, forming a film on the skin surface to play a breathable and anti-bacterial role.

[0038] Glycerin: Gel-like moisturizing property. After forming a film, the film is relatively soft and will not cause cracking due to the opening and closing of skin texture.

[0039] Carboxymethyl cellulose: thickener and suspension stabilizer. It allows bacterial cellulose microfibers to be evenly suspended in the gel, thus forming a stable network porous structure.

[0040] β-Glucan (β1.3-Glucan): Its unique biological functions and physical and chemical properties (such as anticoagulation, antioxidation, promotion of cell proliferation, antibacterial and water absorption) can produce multiple functions such as moisturizing, delaying aging, promoting epithelial fibroblast proliferation and beautifying skin color. In addition, it can also promote wound healing and eliminate wound infections caused by Staphylococcus.

[0041] Epigallocatechin-3-gallate (EGCG): It can regulate the balance of M1 macrophages (promoting inflammatory response) and M2 macrophages (promoting collagen synthesis) in the wound area, thereby inhibiting the inflammatory response. Most chronic wounds are associated with the formation of bacterial biofilms, which are mainly composed of bacteria, polysaccharides, proteins and lipids. They are a tightly hydrated extracellular polymer that can significantly enhance bacterial tolerance to antibiotics and resistance to host immune defense, and are the main cause of bacterial resistance. EGCG can hinder the formation of bacterial biofilms by interfering with the assembly of amyloid fibers and the generation of phosphoethanolamine-modified cellulose fibrils.

[0042] ε-polylysine: It is synthesized by microorganisms, has a molecular weight between 3600-4300, is composed of more than 10 lysine monomers, has a broad-spectrum antibacterial effect, and has inhibitory effects on both Gram-positive and Gram-negative bacteria.

[0043] Toluidine blue (TB): TB is a thiazine cationic dye that has been proven to be an effective photosensitizer that can effectively kill many microorganisms and their virulence factors. However, since TB is prone to dimerization in solution to form aggregates, the production and life of reactive oxygen species (especially singlets) are reduced, which reduces photosensitivity and affects the application of TB in photodynamic therapy (PDT). In the present invention, TB is added to the gel formed by BC and carboxymethyl cellulose, wherein BC and carboxymethyl cellulose can prevent TB from undergoing aggregate reactions, ensure the content of TB monomers, generate more reactive oxygen species (ROS), play the role of anti-inflammatory, sterilization and removal of bacterial toxins, and has the effect of promoting the healing of infected wounds.

[0044] A second typical embodiment of the present invention provides a method for preparing the above-mentioned chronic ulcer wound repair gel, comprising:

[0045] Adding bacterial cellulose into water to obtain bacterial cellulose microfiber suspension;

[0046] dissolving glycerol, a suspension stabilizer, β-glucan, epigallocatechin-3-gallate and ε-polylysine in water to obtain a composite solution;

[0047] Mixing the bacterial cellulose microfiber suspension with the composite solution to obtain a bacterial cellulose-based gel;

[0048] A photosensitizer is added to the bacterial cellulose-based gel, and the mixture is stirred to obtain a chronic ulcer wound repair gel.

[0049] The present invention compounds the bacterial cellulose-based hydrogel with functional components through the above method, and various functional components impart multiple functions to the gel, and various functional components are slowly released in the gel, which is beneficial to the continuous maintenance of the wound healing environment.

[0050] In some examples of this embodiment, the bacterial cellulose is added into water, and the mass ratio of the bacterial cellulose to water is 1:3-5, specifically 1:3, 1:4, 1:5, and so on.

[0051] In some examples of this embodiment, in the composite solution, the concentration of glycerol is 3-5wt%, the concentration of the suspension stabilizer is 0.5-2wt%, the concentration of β-glucan is 0.01-0.5wt%, the concentration of epigallocatechin-3-gallate is 0.01-0.2wt%, and the concentration of ε-polylysine is 0.1-5wt%.

[0052] It should be noted that in the process of preparing the compound solution, various functional ingredients need to be completely dissolved, and the dissolution rate of the functional ingredients can be increased under heating conditions, for example, they can be dissolved in a water bath at 55-65°C.

[0053] In some examples of this embodiment, the volume ratio of the bacterial cellulose microfiber suspension to the composite solution is 5:5-8:2.

[0054] In some examples of this embodiment, the preparation method includes: adding bacterial cellulose to water, mixing at a speed of 6000-10000 r / min for 15-30 minutes, ultrasonic homogenization, and colloid milling to obtain a bacterial cellulose microfiber suspension; preferably, the colloid milling parameter is a gap gradually adjusted from 0.15 mm to 0.1 mm. By using fluid mechanics for dispersion and decomposition, ultrasonic homogenization, and colloid milling, the size of the bacterial cellulose can be reduced to obtain bacterial cellulose microfibers, and the bacterial cellulose microfibers are fully dispersed in water to obtain a suspension.

[0055] In some examples of this embodiment, the suspension stabilizer is carboxymethyl cellulose. The addition of carboxymethyl cellulose can make the fine fibers in the bacterial cellulose evenly suspended in the gel, thereby forming a stable network porous structure and improving the air permeability of the gel.

[0056] In some examples of this embodiment, the molecular weight of the ε-polylysine is 3600-4300. The molecular weight of ε-polylysine is between 3600-4300, and the antibacterial activity is the best.

[0057] In some examples of this embodiment, the mixing is performed by high-pressure homogenization with a pressure of 1000-1800 bar and a temperature of 35-55°C.

[0058] In some examples of this embodiment, the photosensitizer is toluidine blue, and the concentration of toluidine blue in the chronic ulcer wound repair gel is 0.5-5 μM, specifically 0.5 μM, 0.6 μM, 0.8 μM, 1 μM, 1.5 μM, 2 μM, 2.5 μM, 3 μM, 3.5 μM, 4 μM, 4.5 μM, 5 μM, and the like.

[0059] It should be noted that toluidine blue easily undergoes dimerization reaction in solution to form aggregates, which leads to a decrease in photosensitivity. In order to prevent TB from undergoing polymerization reaction in solution, it is added in the last step, using BC and carboxymethyl cellulose to prevent TB from undergoing polymerization reaction and ensure the TB monomer content in the gel.

[0060] In some examples of this embodiment, after the photosensitizer is added and stirred, bubbles are introduced into the gel due to stirring. The presence of bubbles affects the properties of the gel, such as viscosity, stickiness, service life, etc., so the bubbles need to be discharged. Negative pressure degassing can be used to eliminate the bubbles.

[0061] A third typical embodiment of the present invention provides a use of the chronic ulcer wound repair gel or the chronic ulcer wound repair gel prepared by the above preparation method in the preparation of wound dressings.

[0062] In some examples of this embodiment, the wound is a chronic skin ulcer.

[0063] A fourth typical embodiment of the present invention provides a wound dressing, comprising the above-mentioned chronic ulcer wound repair gel or the chronic ulcer wound repair gel prepared by the above-mentioned preparation method.

[0064] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0065] The raw materials used in the following examples, unless otherwise specified, are conventional products and can be purchased.

[0066] Example 1

[0067] A method for preparing a chronic ulcer wound repair gel comprises the following steps:

[0068] (1) Bacterial cellulose and deionized water were mixed in a mass ratio of 1:4, dispersed by fluid mechanics at a speed of 8000 r / min for 25 min, homogenized by ultrasound, and processed by a colloid mill with the gap gradually adjusted from 0.15 mm to 0.1 mm to obtain a bacterial cellulose microfiber suspension.

[0069] (2) 4 g of glycerol, 1.25 g of carboxymethyl cellulose, 0.25 g of β-glucan, 0.1 g of epigallocatechin-3-gallate, and 2.5 g of ε-polylysine were mixed, water was added to make up to 100 g, and the mixture was dissolved in a water bath at 60° C. to obtain a composite solution.

[0070] (3) The bacterial cellulose microfiber suspension obtained in step (1) is mixed with the composite solution obtained in step (2), and subjected to high-pressure homogenization treatment at a pressure of 1400 bar and a temperature of 45° C. to form a bacterial cellulose-based gel.

[0071] (4) Add 3 μM toluidine blue to the bacterial cellulose-based gel obtained in step (3), stir evenly, and degas under negative pressure to obtain a bacterial cellulose-based chronic ulcer wound repair gel.

[0072] Performance characteristics:

[0073] (1) Figure 1 As shown in (A), the appearance of the chronic ulcer wound repair gel obtained in this Example 1 is a translucent amorphous gel. On the one hand, it is convenient to observe the healing of the wound without repeatedly uncovering it for inspection, thus avoiding secondary damage to the wound. On the other hand, it is convenient for filling wounds with subcutaneous tunnels or deeper wounds. The surface of the gel is moist, soft and elastic, and will not cause any discomfort to the patient. The morphology and microstructure of the chronic ulcer wound repair gel obtained in this Example 1 were characterized by scanning electron microscopy (SEM). Figure 1 As shown in (B), the interior of the chronic ulcer wound repair gel is a loose and porous structure, which is conducive to gas exchange. At the same time, its water vapor transmission rate was measured to be 2658.6gm -2 twenty four -h , in line with the relevant index requirements of contact wound dressings. Many microsphere structures are formed inside, which can achieve the sustained release of substances and is conducive to the continuous maintenance of the wound healing environment.

[0074] The gel system constructed by the present invention is a matrix framework for sustained-release drugs, which can be compounded with various active substances and drugs. The active substances of the chronic ulcer wound repair gel prepared by the present invention are β-glucan, epigallocatechin-3-gallate, ε-polylysine and TB. These active substances can be sustained-released, which is beneficial to the continuous maintenance of the wound healing environment.

[0075] Since the sustained-release detection methods of active ingredients TB, β-glucan, epigallocatechin-3-gallate and ε-polylysine are not mature, this example uses cannabidiol (CBD) as a representative of drugs to analyze the sustained-release performance of chronic ulcer wound repair gel. Cannabidiol (CBD) and toluidine blue were added at the same time, and the sustained-release performance of the obtained chronic ulcer wound repair gel was evaluated. The follow-up detection results of cannabidiol (CBD) are shown in Figure 2. Fig. 9 It can be seen that the chronic ulcer wound repair gel provided by the present invention has excellent sustained-release performance.

[0076] (2) The chronic ulcer wound repair gel obtained in Example 1 can be used as a photosensitizer for photodynamic therapy. Toluidine blue has good selectivity for bacteria and can effectively penetrate tissues and distribute to infected target tissues without damaging normal tissues.

[0077] (3) After testing, the pH value of the chronic ulcer wound repair gel obtained in this Example 1 is 5.8. A slightly acidic environment can affect the growth and proliferation of pathogens. The suitable pH value for the growth and proliferation of most pathogens that cause wound infection is 7.2-7.4. For example, the ideal pH value for the growth and proliferation of Staphylococcus aureus is 7.0-7.5, the ideal pH value for Pseudomonas aeruginosa is 6.6-7.0, and the ideal pH value for enterococci is 7.0-9.0. When the pH value is low, the growth of these pathogens is inhibited. In addition, a slightly acidic microenvironment can promote wound healing.

[0078] (4) The BC dressing and the chronic ulcer wound repair gel were co-cultured with fibroblasts, and the cytotoxicity of the gel was evaluated by the changes in cell proliferation. Among them, the control was a high-density polyethylene extract, which is a material that does not produce cytotoxicity. As a negative control, the rest of the medium process and method were the same as the experimental group. The results are shown in Table 1. The study found that the chronic ulcer wound repair gel obtained in Example 1 has low cytotoxicity and is safe and non-toxic to the human body. Both pure BC dressings and chronic ulcer wound repair gel have very low cytotoxicity. In contrast, the chronic ulcer wound repair gel has a higher relative cell proliferation rate, less cytotoxicity and is safer.

[0079] Table 1 Relative proliferation rate of cells (x±s, n=3)

[0080]

[0081] (5) Fibroblast culture test

[0082] The chronic ulcer wound repair gel prepared in Example 1 was applied on 3M skin-like tape, and fibroblasts were coated for co-culture. Figure 2 (A) The growth of fibroblasts on the surface of the chronic ulcer wound repair gel was observed by scanning electron microscopy.

[0083] The results are as follows Figure 2 As shown in (B), fibroblasts can grow in an extended manner on the surface of the chronic ulcer wound repair gel with good growth, indicating that the chronic ulcer wound repair gel can promote wound healing and reduce scar formation.

[0084] (6) Create skin defect wounds on the backs of diabetic rats, and use a small amount of mixed bacterial suspension to infect the skin defect wounds of diabetic rats to construct a chronic ulcer wound model. The diabetic rats with successful modeling were divided into an experimental group and a control group. The experimental group applied the chronic ulcer wound repair gel prepared in Example 1 on the surface of the chronic ulcer wounds of the rats, and the control group did not perform any treatment on the chronic ulcer wounds of the rats. The skin damage repair was detected under a light microscope on the 3rd, 7th, and 15th days. Figure 3 As shown in the figure, through histopathological examination, it was found that the blank control group had obvious inflammatory reaction on the 3rd day, while the chronic ulcer wound repair gel group was relatively less than the control group. On the 3rd day, obvious granulation tissue began to form in both groups. The chronic ulcer wound repair gel group had glandular structure formed, and the epithelialization of the control group was significantly lower than that of the chronic ulcer wound repair gel group. On the 15th day, the control group was basically full of granulation tissue. The chronic ulcer wound repair gel group was basically close to natural skin, with thinning keratinocyte layer, dermis filled with collagen, and corresponding glands also increased.

[0085] The chronic ulcer wound repair gel obtained in Example 1 can bind to the human body's receptors, reduce the secretion of inflammatory factors, control the migration of inflammatory cells, and promote the secretion of the human antimicrobial peptide β-defensin, thereby achieving the effect of inhibiting skin inflammation and enhancing skin immunity, and quickly alleviating skin inflammation problems.

[0086] (7) Antibacterial properties

[0087] The inherent and long-lasting antibacterial activity of wound dressings is essential for preventing bacterial adhesion, inflammatory response and wound infection. The antibacterial properties of the chronic ulcer wound repair gel obtained in Example 1 were tested using Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus as representative bacteria. The test was carried out using Luria-Bertani (LB) solid culture medium. First, the bacteria were subcultured in a suitable culture medium to confirm their concentration. The suspension containing Escherichia coli and Staphylococcus aureus was then divided into equal parts and spread on the surface of the solid culture medium for inoculation. The chronic ulcer wound repair gel was then placed in different positions of the culture medium and irradiated with a wavelength of 630-660nm and a light dose of 10J / cm 2 , Irradiation time: 0-5min of near-infrared laser irradiation treatment, and observe the antibacterial ring after placing in a 37℃ constant temperature box for 24h.

[0088] Test results such as Figure 4 As shown, the chronic ulcer wound repair gel has an inhibitory effect on both Escherichia coli and Staphylococcus aureus.

[0089] (8) Moisturizing

[0090] The good water retention performance of wound dressing is of great significance for providing a lasting moist environment, dissolving necrotic tissue, avoiding scabs, and promoting wound healing. The chronic ulcer wound repair gel obtained in Example 1 was attached to the 3M imitation leather tape, and the 3M imitation leather tape was attached to the outer wall of a container with 37°C water circulation inside. The human body temperature was simulated, and the weight of the chronic ulcer wound repair gel was taken out and recorded at regular intervals, and its water loss rate was calculated.

[0091] The results are as follows Figure 5 As shown, the chronic ulcer wound repair gel obtained in Example 1 has excellent moisture retention, and its water loss rate reaches 50% only after 16 hours, and has a long service life.

[0092] Example 2

[0093] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (1), the mass ratio of bacterial cellulose to deionized water is 1:3, and the remaining steps are consistent with Example 1.

[0094] Example 3

[0095] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (1), the mass ratio of bacterial cellulose to deionized water is 1:5, and the remaining steps are consistent with Example 1.

[0096] Example 4

[0097] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (2), 3 g glycerol, 0.5 g carboxymethyl cellulose, 0.01 g β-glucan, 0.01 g epigallocatechin-3-gallate, and 0.1 g ε-polylysine are mixed and then water is added to 100 g, and the remaining steps are consistent with Example 1.

[0098] Example 5

[0099] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (2), 5 g glycerol, 2 g carboxymethyl cellulose, 0.5 g β-glucan, 0.2 g epigallocatechin-3-gallate, and 5 g ε-polylysine are mixed and then water is added to 100 g, and the remaining steps are consistent with Example 1.

[0100] Example 6

[0101] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (4), 0.5 μM toluidine blue is added to the bacterial cellulose-based gel obtained in step (3), and the remaining steps are consistent with Example 1.

[0102] Example 7

[0103] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (4), 5 μM toluidine blue is added to the bacterial cellulose-based gel obtained in step (3), and the remaining steps are consistent with Example 1.

[0104] After testing, the performance of the chronic ulcer wound repair gel obtained in Examples 2-7 is similar to that of the chronic ulcer wound repair gel obtained in Example 1. The gels have loose porous structures and the water vapor permeability is greater than 2000 g.m. -2 twenty four -h It has a microsphere structure inside, which can slowly release functional ingredients and has good moisturizing properties. It can be used as a photosensitizer for photodynamic therapy. It has a pH value of 5-7, low cytotoxicity, is safe and non-toxic to the human body, can promote wound healing, relieve skin inflammation problems, and inhibit Escherichia coli and Staphylococcus aureus.

[0105] Comparative Example 1

[0106] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (2), carboxymethyl cellulose is not added. The remaining steps are consistent with those of Example 1.

[0107] Figure 6 (A) is a physical picture of the gel obtained in this comparative example 1. Figure 6 (B) is a physical picture of the gel obtained in Example 1 of the present invention. Figure 6 It can be seen that the addition of carboxymethyl cellulose can effectively prevent TB from undergoing polymerization reaction. The present invention has found through research that the effect of carboxymethyl cellulose on preventing TB from undergoing polymerization reaction is better than that of BC, and the presence of the two has a certain synergistic effect. After TB undergoes polymerization reaction, the photodynamic therapy effect is affected. Therefore, the photodynamic therapy effect of the gel obtained in Comparative Example 1 is poor.

[0108] Comparative Example 2

[0109] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (2), glycerol is not added, and the remaining steps are consistent with Example 1.

[0110] Figure 7 The moisture retention of the gel obtained in Comparative Example 2 is such that its water loss rate reaches 50% in about 8 hours. Its moisture retention is worse than that of the gel obtained in Example 1, and its service life is short.

[0111] Comparative Example 3

[0112] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (2), no β-glucan is added, and the remaining steps are consistent with Example 1.

[0113] Comparative Example 4

[0114] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (2), epigallocatechin-3-gallate is not added, and the remaining steps are consistent with those of Example 1.

[0115] Comparative Example 5

[0116] A method for preparing a chronic ulcer wound repair gel, which differs from Example 1 in that: in step (2), ε-polylysine is not added, and the remaining steps are consistent with Example 1.

[0117] To evaluate the effectiveness of the repair gel in repairing chronic ulcer wounds, a small amount of mixed bacterial suspension was used to infect the wounds of diabetic rats. The wounds were then tested with different formulations of gel, and the wound healing was as follows: Figure 8 As shown. Comparative Example 3 did not add β-glucan, the wound healed slowly, the inflammatory reaction was not particularly obvious, and the wound surface was clean. Comparative Examples 4 and 5 had bacterial infection and obvious inflammatory reaction. Although the wound area was reduced after 15 days, the wound was still very deep and there was tissue pus exudation.

[0118] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A chronic ulcer wound repair gel, characterized in that: It comprises a bacterial cellulose hydrogel, and a functional component compounded on the bacterial cellulose hydrogel; The functional component is prepared by mixing glycerol, a suspension stabilizer, beta-glucan, epigallocatechin-3-gallate, epsilon-polylysine and a photosensitizer.

2. The chronic ulcer wound repair gel according to claim 1, characterized in that: The suspension stabilizer is carboxymethyl cellulose; Preferably, the molecular weight of the ε-polylysine is 3600-4300; Preferably, the photosensitizer is toluidine blue.

3. A method for preparing the chronic ulcer wound repair gel according to claim 1, characterized in that: include: Adding bacterial cellulose into water to obtain bacterial cellulose microfiber suspension; dissolving glycerol, a suspension stabilizer, β-glucan, epigallocatechin-3-gallate and ε-polylysine in water to obtain a composite solution; Mixing the bacterial cellulose microfiber suspension with the composite solution to obtain a bacterial cellulose-based gel; A photosensitizer is added to the bacterial cellulose-based gel, and the mixture is stirred to obtain a chronic ulcer wound repair gel.

4. The preparation method according to claim 3, characterized in that: The bacterial cellulose is added into water, and the mass ratio of the bacterial cellulose to water is 1:3-5; In the composite solution, the concentration of glycerol is 3-5wt%, the concentration of the suspension stabilizer is 0.5-2wt%, the concentration of β-glucan is 0.01-0.5wt%, the concentration of epigallocatechin-3-gallate is 0.01-0.2wt%, and the concentration of ε-polylysine is 0.1-5wt%; Preferably, the volume ratio of the bacterial cellulose microfiber suspension to the composite solution is 5:5-8:

2.

5. The preparation method according to claim 3, characterized in that: The preparation method comprises: adding bacterial cellulose to water, mixing at a rotation speed of 6000-10000 r / min for 15-30 minutes, ultrasonically homogenizing, and treating with a colloid mill to obtain a bacterial cellulose microfiber suspension; Preferably, the colloid mill parameter is that the gap is gradually adjusted from 0.15 mm to 0.1 mm.

6. The preparation method according to claim 3, characterized in that: The suspension stabilizer is carboxymethyl cellulose; Preferably, the molecular weight of the ε-polylysine is 3600-4300.

7. The preparation method according to claim 3, characterized in that: The mixing is performed by high-pressure homogenization, with a pressure of 1000-1800 bar and a temperature of 35-55°C.

8. The preparation method according to claim 3, characterized in that: The photosensitizer is toluidine blue, and the concentration of toluidine blue in the chronic ulcer wound repair gel is 0.5-5 μM.

9. Use of the chronic ulcer wound repair gel according to claim 1 or 2 or the chronic ulcer wound repair gel prepared by the preparation method according to any one of claims 3 to 8 in preparing wound dressings; Preferably, the wound is a chronic skin ulcer.

10. A wound dressing, characterized in that: The invention comprises the chronic ulcer wound repair gel according to claim 1 or 2 or the chronic ulcer wound repair gel prepared by any one of the preparation methods according to claims 3-8.

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