Medical silicone gel for scar repair and method of preparation and use thereof

Abstract

The application discloses a medical silicone gel for scar repair and a preparation method and application thereof, and belongs to the technical field of biomedical materials and tissue engineering. The medical silicone gel comprises the following components in percentage by mass: cyclic siloxane 1-10%, silicone 30-50%, polysiloxane polymer 10-30%, gel matrix 1-10%, and the balance is water. The silicone gel provided by the application is stable in property, has no cytotoxicity, has no skin irritation, is easy to spread, has good film forming property, has strong adhesion to skin tissue, has a tension reducing and pressure adding effect on scars, and has a better scar repair effect than that of a commercial product.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of biomedical materials and tissue engineering technology, and particularly relates to a medical silicone gel for scar repair and a preparation method and use thereof. BACKGROUND

[0002] Obvious skin wounds, such as wounds caused by external force injury, surgery, etc. can lead to scar formation. Scar is a general term for the appearance and histopathological changes of normal skin tissue after various trauma, and mainly manifests in that the tissue is obviously higher than the surrounding normal skin, the surface is red or purple, the local thickening is hard, and itching and pain are felt. In many cases, scar can lead to reduced touch, loss of flexibility and loss of range of motion, and the scar existing in the exposed part of the skin such as the face can cause obvious aesthetic problems. Therefore, there is a need for treatment methods and means to minimize or eliminate scar.

[0003] Under normal circumstances, cotton gauze or various polymers are used in clinic to nurse skin wounds, and the existing wound dressings cannot provide a closed and moist repair environment for the wound, often causing problems such as infection and scar hyperplasia, and the conventional wound dressing cannot be applied to the wound nursing of the joint movement or irregular part, and the medical tape is needed to fix the dressing, which not only affects the normal activity of the patient, but also causes aesthetic problems.

[0004] Silicone gel is a commonly used product for scar repair at present, and its main component is dimethyl silicone oil (silicone). The mechanism of silicone gel in reducing the appearance of scar is not clear at present, and it is speculated that it provides a closed and moist environment for scar tissue, including increased hydration, pH control, temperature rise and oxygen tension control, to promote the partial improvement of fibroblasts and collagen cells in scar tissue.

[0005] However, the conventional silicone gel product has the following defects: 1. Most of them are oily products, which are difficult to apply, and are difficult to clean after application. For patients with large area skin damage, pressure application and cleaning are needed, which brings strong pain to the patient; 2. The adhesion of silicone gel to the skin is weak, and it is easy to break and fall off due to scratching when subjected to external force friction; 3. Silicone gel is soft in texture and has weak adhesion to the skin, and cannot bring pressure and tension reduction to the scar to be repaired, affecting the scar repair effect. SUMMARY

[0006] To address the deficiencies of the prior art, the present invention provides a medical silicone gel for scar repair. The gel exhibits stable storage performance, is non-cytotoxic, and does not irritate the skin. The gel has strong adhesion to the skin, providing gentle pressure and a barrier effect on the scar area. It also reduces tension on the scar area, disrupting collagen synthesis and deposition in the scar area, thereby inhibiting excessive scar growth. The silicone gel provided by the present invention is easy to form a film and clean, resolving the difficult cleaning and application issues of conventional products on the market, and alleviating the pain patients experience during medication changes during long-term treatment.

[0007] Unless otherwise specified, the scars described in the present invention include, but are not limited to, pathological scars caused by burns, trauma, surgery, and hypertrophic scars caused by skin trauma, and do not include open wounds or unhealed wounds.

[0008] The present invention includes the following technical solutions:

[0009] In a first aspect, the present invention provides a medical silicone gel, which comprises the following components, calculated by mass percentage: 1-10% cyclic siloxane, 30-50% silicone, 10-30% polysiloxane polymer, 1-10% gel matrix, and the balance being water.

[0010] The polysiloxane polymer is obtained by cross-linking and polymerizing polymethyl hydrogen siloxane and vinyl polysiloxane prepolymer under platinum catalysis, wherein the vinyl polysiloxane prepolymer is obtained by polymerizing cyclosiloxane and methyl vinyl cyclosiloxane under acid or base catalysis conditions.

[0011] Preferably, the cyclosiloxane is selected from one or a combination of two or more of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane; and the methylvinylcyclosiloxane is selected from one or a combination of two or more of tetramethyltetravinylcyclotetrasiloxane, pentamethylpentavinylcyclopentasiloxane, and hexamethylhexavinylcyclohexasiloxane.

[0012] In a specific embodiment of the present invention, the polysiloxane polymer is prepared by the following method:

[0013] a1) adding cyclosiloxane and methylvinylcyclosiloxane sequentially to a reaction kettle in a mass ratio of 1:(1-3) under base catalysis, raising the temperature to 60-90° C. under nitrogen protection, reacting at this temperature for 2-3 hours, and then removing water by distillation at reduced pressure to obtain a transparent oily vinyl polysiloxane prepolymer;

[0014] a2) adding the vinyl polysiloxane prepolymer and polymethyl hydrogen siloxane in a mass ratio of 1:1 into a reaction kettle, adding a platinum catalyst, raising the temperature to 60-65° C. under nitrogen protection, keeping the temperature to react overnight, and extracting with methanol to obtain an oily substance which is a polysiloxane polymer.

[0015] Preferably, the base catalyst in step a1) is potassium hydroxide or tetramethylammonium hydroxide.

[0016] Preferably, the cyclosiloxane in step a1) is dodecamethylcyclohexasiloxane, and the methylvinylcyclosiloxane is hexamethylhexavinylcyclohexasiloxane.

[0017] In a specific embodiment of the present invention, the platinum catalyst is a Karstedts catalyst.

[0018] The gel matrix is ​​hyaluronic acid or a hyaluronic acid derivative.

[0019] In one embodiment of the present invention, the gel matrix is ​​selected from hyaluronic acid with a molecular weight of 10-20K.

[0020] The cyclic siloxane is selected from one or a combination of two or more of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane.

[0021] In a preferred embodiment of the present invention, the cyclic siloxane is octamethylcyclotetrasiloxane.

[0022] The silicone described in the present invention is polydimethylsiloxane with a viscosity between 100 and 500 cSt.

[0023] In a preferred embodiment of the present invention, the silicone gel comprises the following components, calculated by mass percentage: 5-10% octamethylcyclotetrasiloxane, 40-50% silicone, 20-30% polysiloxane polymer, 5-10% hyaluronic acid, and the balance is water.

[0024] In a specific embodiment of the present invention, the silicone is preferably a modified silicone, which is prepared by the following method:

[0025] Under nitrogen atmosphere, polymethylhydrogensiloxane was added to the reactor, and the modifier was slowly added under stirring. The catalyst Karstedts catalyst was dissolved in toluene and slowly added dropwise to the reactor. The temperature was raised to 60-65°C, and the reaction was kept warm overnight. The oily substance was extracted with methanol, and the modified silicone was obtained.

[0026] The modifier is methoxy polyethylene glycol monoacrylate, the structural formula of which is The average molecular weight is 480, and n is an integer between 8 and 11.

[0027] Preferably, the mass ratio of polymethylhydrogensiloxane to modifier is 1:(1-1.5).

[0028] In the most preferred embodiment of the present invention, the silicone gel comprises the following components, calculated by mass percentage: 10% octamethylcyclotetrasiloxane, 40-50% modified silicone, 20-30% polysiloxane polymer, 10% hyaluronic acid, and the balance is water.

[0029] Furthermore, the silicone gel further comprises 0.1-1% menthol and / or 0.1-1% ascorbic acid.

[0030] In a second aspect, the present invention provides a method for preparing medical silicone gel, the method comprising the following steps:

[0031] b1) thoroughly mixing the water and the gel matrix under stirring to form a homogeneous medium;

[0032] b2) adding cyclic siloxane and polysiloxane polymer to the silicone and mixing uniformly;

[0033] b3) adding the mixed solution of (2) to the homogeneous medium of (1) under stirring, adjusting the pH to 6.0-7.0, stirring evenly to form a gel state, ultrasonically degassing, and packaging for storage.

[0034] In a third aspect, the present invention provides a use of a medical silicone gel in at least one of the following:

[0035] c1) Application in the preparation of materials for scar repair;

[0036] c2) Use in the preparation of antibacterial dressings;

[0037] c3) Application in the preparation of medical devices.

[0038] The medical silicone gel provided by the present invention has the following technical advantages:

[0039] The silicone gel provided by the present invention has good storage stability, no cytotoxicity, no skin irritation, is easy to apply, and has good film-forming properties, making the gel easy to operate during application and dressing changes, and has a scar repair effect that is better than commercially available products.

[0040] The polysiloxane polymer prepared by the present invention is a cross-linked polysiloxane compound. As a gel component, it has good film-forming properties and can increase the adhesion of the gel film to the skin, reduce the pulling of external tension on the wound site, and prevent the scar from becoming wider and larger due to the influence of external forces. In addition, as the gel film loses water and shrinks, it has an inward pulling effect on the skin of the scar site, has a pressure-increasing and tension-reducing effect on the scar site, affects the arrangement of collagen in the scar site, and inhibits excessive scar proliferation.

[0041] The present invention uses active group-modified silicone. The bioactive group-modified silicone has better hydrophilicity, which makes the silicone gel more water-retaining, reduces the stimulation of water loss on fibroblasts, inhibits the proliferation and expansion of scar tissue, and the modified silicone can also increase the adhesion between the gel film and skin tissue.

[0042] The aqueous solution of hyaluronic acid is a viscoelastic fluid. Hyaluronic acid has a good moisturizing and water-retaining effect on skin scar tissue. The present invention uses hyaluronic acid as a medium to disperse silicone and other polysiloxane materials. Compared with conventional silicone gels, it has a higher degree of hydration and is easier to apply. In addition, the large number of hydrophilic groups in hyaluronic acid have a positive effect on promoting tissue repair and reducing tissue fibrosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the rabbit skin irritation test model.

[0044] Figure 2 Polysiloxane polymer prepared in Preparation Example 1 1 H NMR characterization diagram.

[0045] Figure 3 Modified silicone prepared in Preparation Example 4 1 H NMR characterization diagram.

[0046] Figure 4 Pictures of the incision site on days 0, 14, and 21 after surgery.

[0047] Figure 5 Statistical chart of scar elevation index (SEI) in animal experiments. DETAILED DESCRIPTION

[0048] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.

[0049] Preparation of polysiloxane polymers

[0050] The synthetic route of the polysiloxane polymer is as follows:

[0051] Step 1:

[0052]

[0053] Step 2:

[0054]

[0055] Preparation Example 1

[0056] S1: Using KOH as a catalyst (1 g), under nitrogen protection, 200 g of octamethylcyclotetrasiloxane and 200 g of tetramethyltetravinylcyclotetrasiloxane were added to a reaction kettle. The temperature was raised to 90°C and the reaction was kept at this temperature for 3 h. The water was then removed by distillation under reduced pressure to obtain a transparent oily polysiloxane prepolymer.

[0057] S2: The oily polysiloxane prepolymer obtained in step S1 and the same mass of polymethylhydrogensiloxane were simultaneously put into the reactor, and Karstedts catalyst solution was slowly added. The temperature was raised to 60°C under nitrogen protection, and the temperature was kept to react overnight. After cooling to room temperature, cold methanol was added for extraction, and the oily substance was taken and subjected to 1 H NMR characterization, the results are as follows Figure 2 As shown, a characteristic peak of Si-CH3 appears at 0.1-0.3ppm, a characteristic peak of -CH2-CH2- appears at about 0.8ppm, and the characteristic peak of CH2=CH2 of the polysiloxane prepolymer obtained in the first step disappears at about 5.0ppm, indicating that the target product polysiloxane polymer 1 is synthesized.

[0058] Preparation Example 2

[0059] The preparation method and synthesis conditions were the same as those in Preparation Example 1. The same mass (200 g) of decamethylcyclopentasiloxane and pentamethylpentavinylcyclopentasiloxane were reacted under KOH catalyst to obtain a polysiloxane prepolymer. The prepared polysiloxane prepolymer was used as a raw material and reacted with the same mass of polymethylhydrogensiloxane under Karstedts catalyst overnight. The mixture was extracted with methanol to obtain an oily substance, which was polysiloxane polymer 2.

[0060] Preparation Example 3

[0061] The preparation method and synthesis conditions are the same as those in Preparation Example 1. The same mass (200 g) of dodecamethylcyclohexasiloxane and hexamethylhexavinylcyclohexasiloxane are reacted under KOH catalyst to obtain a polysiloxane prepolymer. The prepared polysiloxane prepolymer is used as a raw material and reacted with the same mass of polymethylhydrogensiloxane under Karstedts catalyst overnight. The mixture is extracted with methanol to obtain an oily substance, polysiloxane polymer 3. The NMR characterization images of the polysiloxane products obtained in Preparation Examples 1-3 of the present invention are similar. To save space, the present invention only reflects the NMR characterization results of the product of Preparation Example 1.

[0062] Preparation of modified silicone

[0063] Preparation Example 4

[0064] The synthetic route of the modified silicone is as follows:

[0065]

[0066] Under nitrogen atmosphere, 400g of polymethylhydrogensiloxane was added to the reactor, and the same mass of methoxypolyethylene glycol monoacrylate was slowly added under stirring. The catalyst Karstedts catalyst was dissolved in toluene, and the catalyst solution was slowly added dropwise to the reactor. The temperature was raised to 60°C and kept to react overnight. After cooling to room temperature, cold methanol was added for extraction, and the oily substance was taken and subjected to 1 H NMR characterization, the results are as follows Figure 3 As shown, a characteristic peak of Si-CH3 appears at 0.1-0.3 ppm, a characteristic peak of -CH2-CH2- connected to the carbonyl group appears between 1.0-2.0 ppm, and a characteristic peak of -O-CH3 appears between 3.0-4.0 ppm, indicating that methoxy polyethylene glycol monoacrylate is coupled to the polymethyl hydrogensiloxane structure to form a cross-link to prepare the modified silicone.

[0067] Preparation of medical silicone gel

[0068] Example 1

[0069] S1: Dissolve 10 parts of hyaluronic acid (molecular weight 20K) in 10 parts of deionized water, and mix thoroughly to form a homogeneous hyaluronic acid solution;

[0070] S2: 10 parts by mass of octamethylcyclotetrasiloxane, 30 parts of the polysiloxane polymer 1 prepared in Preparation Example 1, and 40 parts of silicone (viscosity 200 cSt) were thoroughly mixed under stirring;

[0071] S3: Slowly add the mixed solution of step S2 to the hyaluronic acid solution of step S1 under stirring, adjust the pH to about 7 with triethylamine, and the mixture is in a gel state, ultrasonically degassing, and encapsulating to form a gel preparation.

[0072] Example 2

[0073] The preparation method and raw materials are the same as those in Example 1, except that the polysiloxane polymer 1 prepared in Preparation Example 1 in step S2 is replaced by the polysiloxane polymer 2 prepared in Preparation Example 2 of the same mass.

[0074] Example 3

[0075] The preparation method and raw materials are the same as those in Example 1, except that the polysiloxane polymer 1 prepared in Preparation Example 1 in step S2 is replaced by the polysiloxane polymer 3 prepared in Preparation Example 3 of the same mass.

[0076] Example 4

[0077] The preparation method and raw materials are the same as those in Example 1, except that 40 parts of silicone in step S2 is replaced with the same mass of modified silicone prepared in Preparation Example 4 of the present application.

[0078] Example 5

[0079] The preparation method and raw materials are the same as those in Example 2, except that 40 parts of silicone in step S2 is replaced with the same mass of modified silicone prepared in Preparation Example 4 of the present application.

[0080] Example 6

[0081] The preparation method and raw materials are the same as those in Example 3, except that 40 parts of silicone in step S2 is replaced with the same mass of modified silicone prepared in Preparation Example 4 of the present application.

[0082] Comparative Example 1

[0083] The preparation method and raw materials are the same as those in Example 1, except that the polysiloxane polymer prepared in Preparation Example 1 in step S2 is replaced with the same mass of silicone (viscosity 200 cSt).

[0084] Biosafety evaluation of the medical silicone gel prepared by the present invention

[0085] Experiment 1 Cytotoxicity Assay

[0086] Detection method:

[0087] Step 1: According to GB / T 16886.12-2017-2017 Medical Devices-Biological Evaluation-Part 12: Sample Preparation and Reference Materials, the silicone gels prepared in Examples 1-6 and Comparative Example 1 are extracted with DMEM serum-free medium at a volume-mass ratio of 1 mL:0.1 g, the extraction conditions are room temperature, 36 h, and after extraction, the bacteria are removed by filtering with a 0.22 μm filter membrane and stored for use;

[0088] Step 2: Take human epidermal cells HaCaT cells in the logarithmic growth phase, digest, and prepare a cell suspension with a concentration of 5x10 4 6 / mL, inoculate 200 μL per well in a 96-well plate, and after the cells are completely attached, remove the old culture medium, add the extract obtained in step 1 (200 μL), set up 5 replicate wells for each extract, set up a blank control, and culture under normal conditions for 24 h;

[0089] Step 3: Remove the drug solution in the well plate, add 200 μL of CCK-8 diluent, continue to incubate for 1 h, and detect the absorbance value of each well liquid at 450 nm with an enzyme-linked immunoassay instrument, and calculate the cell proliferation rate.

[0090] Cell proliferation rate (%) = (absorbance value of experimental group / absorbance value of blank control group) x 100%

[0091] According to the cytotoxicity evaluation grade table specified in the United States Pharmacopoeia shown in Table 1, the toxicity of the medical silicone gels prepared in Examples 1-6 of the present invention and Comparative Example 1 was evaluated. The results are shown in Table 2.

[0092] Table 1 Cytotoxicity evaluation grade table

[0093]

[0094]

[0095] Table 2 Cytotoxicity evaluation of materials prepared by the present invention

[0096] Extract source Cell proliferation rate (%) Toxicity classification Toxicity evaluation Example 1 Gel 100.3±5.4 0 qualified Example 2 Gel 101.9±4.9 0 qualified Example 3 Gel 93.2±6.2 1 qualified Example 4 Gel 97.4±5.7 1 qualified Example 5 Gel 90.6±7.7 1 qualified Example 6 Gel 92.5±4.0 1 qualified Comparative Example 1 Gel 105.3±3.1 0 qualified

[0097] As shown in Table 2, the cell proliferation rate data indicates that HaCaT cells cultured with the medical silicone gel extracts prepared in accordance with the present invention achieved proliferation rates exceeding 90%. These cells, classified as either Grade 0 or Grade 1 according to the cytotoxicity evaluation table, all passed the toxicity evaluation, demonstrating that the medical silicone gels prepared in accordance with the present invention are non-cytotoxic and exhibit excellent cell biocompatibility. Furthermore, under a microscope, cells in all experimental groups maintained a polygonal epithelial-like appearance, growing uniformly and adherently, with no abnormalities in cell morphology.

[0098] Experiment 2 Skin irritation test

[0099] According to the requirements of GB / T 16886.10-2005 / ISO 10993-10:2002, Biological Evaluation of Medical Devices Part 10: Irritation and Delayed Hypersensitivity Tests, the irritation of the medical silicone gels prepared in Examples 1-6 of the present invention to the skin was tested. Two healthy, newly adult albino rabbits were used as test subjects and were raised in accordance with the provisions of GB / T16886.2. 4-24 hours before the test, the hair on both sides of the spine on the back of the animals was removed (approximately 10 cm × 15 cm area) to serve as the test and observation site. Test gels 1-6 were applied directly to the skin. Figure 1 The marked skin areas and the remaining marked areas were used as observation sites, and normal saline was applied. The reactions of the marked areas were observed under natural light. The skin reactions at each provocation site were observed and recorded 24 hours, 48 ​​hours, and 72 hours after provocation according to the scoring system in Table 3. The scoring results are shown in Table 4.

[0100] Table 3 Skin reaction scoring system

[0101]

[0102] Table 4 Skin irritation reaction of medical silicone gel

[0103]

[0104]

[0105] The skin irritation scoring results reported in Table 4 indicate that the medical silicone gels prepared in Examples 1-6 of the present invention did not cause skin edema during application. Within 24 hours of application, slight erythema appeared at the application site, but this disappeared 48 hours after application. These results demonstrate that the silicone gels prepared in this invention are non-irritating to the skin.

[0106] Tissue adhesion test of the medical silicone gel prepared by the present invention

[0107] Experiment 3 Tissue adhesion strength test

[0108] The present invention uses an in vitro burst pressure test model to evaluate the adhesion strength of the medical silicone gel prepared in accordance with the present invention to biological tissue. The in vitro burst pressure test was conducted according to ASTM F2392-04 (Standard Test Method for Bursting Strength of Surgical Sealants). The principle of this test is to measure the maximum burst pressure that the silicone gel can maintain at the tissue leakage point after film formation.

[0109] Test method:

[0110] Imitation of skin tissue substrate, a hole with a diameter of 3.0 mm was made on the surface of a collagen casing with a thickness of about 0.1-0.5 mm. A syringe was used to apply 500 μL of the medical silicone gel to be tested to the hole of the collagen casing to seal the hole, forming a coating layer with a thickness equivalent to that of the collagen casing. The gel was allowed to stand at room temperature for 10-15 minutes until the gel film formed. The collagen casing to be tested was placed on the test unit, and a digital pressure gauge was used to record the pressure when the silicone gel film ruptured as the maximum burst pressure. The silicone gels prepared in Examples 1-6 of the present invention and Comparative Example 1 were tested separately, with 10 parallel samples of each gel. The test results are shown in the following table:

[0111] Table 5 Burst pressure test of medical gel

[0112]

[0113]

[0114] The silicone gel prepared in Comparative Example 1 is compared with Example 1, the difference is that the polysiloxane polymer 1 prepared in the application is replaced by the same mass of conventional silicone. From the burst pressure results obtained by detection, it can be seen that the polysiloxane polymer 1 prepared in the application has the effect of significantly increasing the burst pressure of the gel compared with the conventional silicone. The inventor analyzes the reason and believes that the polysiloxane polymer prepared by the inventor has good film-forming properties and stronger adhesion to the skin tissue. Therefore, compared with the conventional silicone, the gel film added with the polysiloxane polymer has stronger pressure resistance, and the detected burst pressure value is larger.

[0115] The silicone gels prepared in Examples 1-3 of the application differ in that the addition reaction monomers for forming the polysiloxane polymer are different. From the burst pressure detection results, it can be seen that the gel of Example 3 has better pressure resistance and stronger adhesion to the skin tissue, indicating that the polysiloxane polymer used in Example 3 has better effect, and the polysiloxane prepolymer obtained by ring-opening polymerization of dodecamethylcyclohexasiloxane and hexamethylhexavinylcyclohexasiloxane is better in essence. The skilled person analyzes the reason and believes that it may be because compared with tetramethyltetraethenylcyclotetrasiloxane, hexamethylhexavinylcyclohexasiloxane will polymerize to form a reaction monomer containing more vinyl groups, and when it occurs addition reaction with polymethylhydrosiloxane, it will form a polysiloxane polymer with higher crosslinking state, which has stronger adhesion to the skin during film formation.

[0116] From the detection data in Table 5, it can also be seen that when the conventional silicone in the silicone gel system is replaced by the modified silicone prepared in the application, the pressure resistance of the gel film can be further improved, because compared with the conventional silicone, the modified silicone molecule is coupled with a methoxy polyethylene glycol monoacrylate unit, and a large number of oxygen atoms can form a binding force similar to hydrogen bond with the skin surface in a humid environment, so that the adhesion of the gel film to the skin tissue is further enhanced. On the basis of the above experiments, the silicone gels prepared in Examples 4-6 of the application are used for animal experiments.

[0117] Scar repair ability test of the medical silicone gel prepared by the present invention

[0118] Experiment 4: Scar repair ability detection

[0119] Test method:

[0120] Twelve rats were randomly divided into 4 groups, 3 rats in each group. Before anesthesia, the rats were fasted for 12 h, and then intraperitoneally injected with 10% chloral hydrate to induce general anesthesia. After general anesthesia, the back hair (4 cm x 6 cm) on the medial side of the scapula was shaved, and then iodine tincture was used for disinfection, followed by alcohol to remove iodine to reduce skin mucosa irritation. Two circular incisions deep to the fascia were made on both sides of the spine of the 12 rats using a biopsy punch, and then the wound secretions were cleaned with normal saline, and the residual liquid was wiped off with sterile gauze.

[0121] After the model was established, the incisions were covered with conventional dressings, and the dressings were replaced every 3 days. On the 7th day after the operation, the dressings were removed to expose the wound surface. Starting on the 7th day after the operation, the test side of the 4 groups of rats was coated with the medical silicone gel prepared in Examples 4-6 and a commercially available silicone gel, respectively, and the control side was coated with a commercially available sterile gauze, all of which were replaced every 3 days. The images of the incisions were collected on the 14th day after the operation and the 21st day after the operation, respectively. As shown in FIG. 6, on the 14th day after the operation, granulation tissue was generated on the edge of the incision on the control side, and there was a certain degree of swelling, but the skin on the test side was rapidly epithelialized, and the size of the wound was significantly smaller than that of the control. It was an unexpected finding by the present inventors that the skin on the side using the medical silicone gel had a tendency to be pulled inward, which was more conducive to wound healing. This was because the silicone gel prepared in the present application had good film-forming property and skin adhesion, and during the volume shrinkage of the gel due to water loss, there was a significant pulling force on the wound skin, achieving the effect of tension reduction, while the sterile gauze could not achieve this effect at all. On the 21st day after the operation, the scab on the test side fell off, the wound site was neat, and no obvious linear scar was formed, but the scab on the control side had not fallen off, and the skin around the scab was irregularly raised, forming an obvious scar. Figure 4

[0122] On the 21st day after the operation, the rats were euthanized, and the thickness of the scar tissue on the test side and the control side was measured, and the SEI of the scar position was calculated. The formula for calculating the scar elevation index (SEI) is as follows:

[0123] SEI = (A + B) / B,

[0124] A is the thickness of the scar tissue higher than the normal epidermal skin, and B is the thickness of the normal epidermal skin. The test results are shown in the following table.

[0125] Table 6 SEI statistical results of the scar position

[0126]

[0127] ​From the statistical results of SEI of the scar area of ​​rats, it can be seen that the scar elevation index on the side using the medical silicone gel prepared by the present invention is significantly lower than that on the side using sterile gauze. The inventors analyzed the reasons and believed that compared with sterile gauze, the silicone gel prepared by the present invention has the effect of sterile covering and water retention on the scar area, which is beneficial to the partial improvement of fibroblasts and collagen in the scar tissue, so that the collagen is rearranged close to normal skin, fibrosis is inhibited and scar formation is reduced. In addition, another important reason is that the silicone gel provided by the present invention has a strong adhesion to the skin after forming a film. When the volume of the gel shrinks as it loses water, it exerts an inward pulling force on the scar area of ​​the skin, which has a tension-reducing effect on the scar, and the strong adhesion also causes the gel film to have a pressurizing effect on the scar area, promoting the orderly rearrangement of collagen in the scar area to be close to normal skin. Moreover, through Figure 5 It can be seen from the SEI statistical results that compared with commercially available gels, the silicone gel prepared by the present invention has a more significant effect of reducing scar protrusion. Technicians believe that this is related to the tension-reducing and pressure-increasing effects of the silicone gel prepared by the present invention.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A medical silicone gel, characterized in that: The medical silicone gel comprises the following components in percentage by mass: 10% octamethylcyclotetrasiloxane, 40-50% modified silicone, 20-30% polysiloxane polymer, 10% hyaluronic acid, and the balance water; The polysiloxane polymer is obtained by cross-linking and polymerizing polymethyl hydrogen siloxane and vinyl polysiloxane prepolymer under platinum catalysis, wherein the vinyl polysiloxane prepolymer is obtained by polymerizing cyclosiloxane and methyl vinyl cyclosiloxane under acid or base catalysis, the cyclosiloxane is selected from dodecamethylcyclohexasiloxane, and the methyl vinyl cyclosiloxane is selected from hexamethylhexavinylcyclohexasiloxane; The modified silicone is prepared by the following method: under a nitrogen atmosphere, polymethyl hydrogen siloxane is added to a reactor, a modifier is slowly added under stirring, a Karstedts catalyst is dissolved in toluene, and the mixture is slowly added dropwise to the reactor, the temperature is raised to 60-65° C., the reaction is kept warm overnight, and methanol is extracted to obtain an oily substance, which is the modified silicone, and the modifier is methoxy polyethylene glycol monoacrylate.

2. The medical silicone gel according to claim 1, characterized in that The polysiloxane polymer is prepared by the following method: a1) Under base catalysis, cyclosiloxane and methylvinylcyclosiloxane are sequentially added to a reaction kettle in a mass ratio of 1:(1-3). The temperature is raised to 60-90°C under nitrogen protection, and the reaction is carried out at this temperature for 2-3 hours. The water is then removed by distillation at reduced pressure to obtain a transparent oily vinyl polysiloxane prepolymer. a2) adding the vinyl polysiloxane prepolymer and polymethyl hydrogen siloxane in a mass ratio of 1:1 to a reaction kettle, adding a platinum catalyst, raising the temperature to 60-65° C. under nitrogen protection, keeping the temperature to react overnight, and extracting with methanol to obtain an oily substance which is a polysiloxane polymer; Wherein, the cyclosiloxane in step a1) is dodecamethylcyclohexasiloxane, and the methylvinylcyclosiloxane is hexamethylhexavinylcyclohexasiloxane.

3. The medical silicone gel according to claim 1, characterized in that The silicone gel further comprises menthol 0.1-1% and / or ascorbic acid 0.1-1%.

4. A method for preparing the medical silicone gel according to any one of claims 1-2, comprising the following steps: b1) Mixing water and hyaluronic acid thoroughly with stirring to form a homogeneous medium; b2) adding octamethylcyclotetrasiloxane and polysiloxane polymer to the modified silicone and mixing them uniformly; b3) Under stirring, add the mixed solution of (2) to the homogeneous medium of (1), adjust the pH to 6.0-7.0, stir evenly to form a gel state, perform ultrasonic degassing, and encapsulate for storage.

5. Use of the medical silicone gel according to any one of claims 1 to 3 in preparing a material for scar repair.

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