Nano medical gel dressing and preparation method thereof

Abstract

The invention relates to a nano medical gel dressing and a preparation method thereof, gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate are used as raw materials, and the raw materials are mixed and cross-linked to obtain the medical dressing gel. The used raw materials are non-toxic and harmless, the biocompatibility is good, a film can be formed to cover the wound surface, the physical protection effect is achieved, external stimulation to the wound surface is reduced, then tissue repair is promoted, and the formed three-dimensional network structure is good in stability, has excellent water absorption and storage effects, is high in drug loading capacity, and has a good application prospect. The nano titanium dioxide and the polyhexamethylene guanidine have a synergistic antibacterial effect, so that the antibacterial efficiency and durability are improved, the purpose of rapid sterilization is achieved, meanwhile, the overall density of the gel is increased, polymer entanglement is tighter, the compression strength is improved, the tensile strength and the elongation at break are improved, and the mechanical property is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of medical gel dressings, and in particular relates to a nano medical gel dressing and a preparation method thereof. Background Art

[0002] Skin, as the epidermal tissue of the human body, plays a role in protecting the internal environment of the body and maintaining its stability. The ultimate goal of skin injury treatment is to rebuild the skin barrier function. Excellent medical dressings can provide an environment conducive to wound healing, have good biocompatibility and anti-infection ability, and protect the skin by covering damaged skin to form a wound healing environment. It is a common medical device with broad prospects and research space.

[0003] There are many types of medical dressings. The dressings currently used are divided into fibers, films, sponges, hydrogels, hydrocolloids, and medical adhesives. Among them, hydrogel dressings have the advantages of soft texture, ability to keep the wound moist, and good biocompatibility. They are not easy to adhere to wound tissue, thus avoiding secondary damage. Environmentally responsive hydrogel dressings loaded with active drugs can achieve controlled release of drugs, improve drug efficacy, thereby preventing infection, eliminating inflammatory responses, and promoting wound healing.

[0004] Chinese patent CN104906625A discloses a method for preparing a medical hydrogel, comprising the following steps: pouring deionized water into a reactor, heating the reactor, then slowly adding lemon peel pectin and gelatin, while mechanically stirring, adding lemon peel pectin and gelatin, continuing to stir, then adding chitosan, soybean oligosaccharides, polycaprolactone, and chlorhexidine acetate to the reactor, while mechanically stirring evenly, after the above materials are mixed, cooling the hydrogel to room temperature, and obtaining a medical hydrogel. The medical hydrogel has good biocompatibility and air permeability, but its antibacterial effect is average, and its mechanical properties are poor, and it is easy to break during use.

[0005] Chinese patent CN108030954A discloses a medical wound dressing containing nano polysaccharides, including a wet dressing, which is a hydrocolloid dressing or a hydrogel dressing or a silicone gel dressing or a seaweed salt dressing. Nano polysaccharide compounds or derivatives are also added to mix the nano polysaccharide with the wet dressing, so that the wound dressing can quickly absorb wound exudate and has good moisturizing properties, while assisting in enhancing the mechanical properties of the dressing. However, the antibacterial effect of the medical wound dressing is poor.

[0006] Therefore, it is of great practical significance to develop a medical gel dressing with excellent mechanical properties and excellent antibacterial effect. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a nano medical gel dressing and a preparation method thereof, which not only solves the problem of poor antibacterial effect of medical dressings, but also has good mechanical properties, excellent water absorption and storage effects, and strong drug loading capacity.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: A method for preparing a nano medical gel dressing comprises the following steps: S1. Disperse nano titanium dioxide in anhydrous ethanol, and after uniform dispersion, add γ-glycidyloxypropyltrimethoxysilane, mix, heat, and react in a nitrogen atmosphere. After the reaction is completed, filter, wash, and vacuum dry at 60° C. for 12 h to obtain epoxidized titanium dioxide; S2, ultrasonically dispersing epoxidized titanium dioxide into deionized water, adding polyhexamethylene biguanide, stirring and mixing, reacting, filtering, washing, and drying at 60° C. for 24 h after the reaction is completed to obtain amino-modified titanium dioxide; S3, ultrasonically dispersing amino-modified titanium dioxide into deionized water, adding sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, stirring and mixing, reacting, filtering and freeze-drying after the reaction to obtain modified titanium dioxide; S4. Stir and mix gelatin and deionized water for 1 hour. After mixing evenly, add polyethylene glycol, modified titanium dioxide and sodium alginate, and stir and mix for 2 to 4 hours. After stirring and mixing, let stand for 12 hours and sterilize to obtain a nano medical gel dressing.

[0009] In the present invention, γ-glycidyloxypropyltrimethoxysilane is used to modify nano titanium dioxide, and epoxy groups are introduced on the surface of nano titanium dioxide to obtain epoxidized titanium dioxide. The amino groups on polyhexamethylene biguanide and the epoxy groups on epoxidized titanium dioxide undergo a ring-opening reaction, and a large number of hydroxyl groups, amino groups and flexible long chains are introduced to obtain amino-modified titanium dioxide. The amino groups on the amino-modified titanium dioxide react with sodium hyaluronate under the action of 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide to obtain modified titanium dioxide, and carboxyl groups and hydroxyl groups are introduced. Gelatin, modified titanium dioxide, polyethylene glycol, sodium alginate and deionized water are stirred and mixed to obtain a nano medical gel dressing.

[0010] The sodium hyaluronate in the present invention is a natural glycosaminoglycan, which exists in the extracellular matrix of most tissues and contains abundant carboxyl and hydroxyl groups, which can promote the migration and proliferation of fibroblasts and prevent the formation of scars. At the same time, sodium hyaluronate can absorb and retain skin moisture, providing a lasting moisturizing effect. It has a strong water absorption capacity and can penetrate into the bottom layer of the skin to provide lasting moisture nourishment for the skin, and has excellent moisturizing effect.

[0011] Sodium alginate is non-toxic, biocompatible, gelatinous, and has good thermal stability. It is widely used in medical dressings and other fields. Sodium alginate has good moisturizing properties, can maintain a moist environment on the wound surface, promote cell proliferation and tissue regeneration, thereby accelerating wound healing, and has certain antibacterial and anti-inflammatory effects, which helps to reduce the risk of bacterial infection, and reduce the inflammatory response around the wound surface, regulate the permeability of the liquid in the wound surface, reduce the loss of exudate, protect the wound surface environment, and accelerate the repair of the tissue at the bottom of the wound surface.

[0012] Gelatin is a product of partial hydrolysis of collagen. It is an amphoteric substance that is both acidic and alkaline. It is non-antigenic and easily absorbed. As a carrier material, gelatin provides good biocompatibility and biodegradability in medical gel dressings. It helps in the targeted delivery of drugs and improves the bioavailability of drugs in the body.

[0013] Polyethylene glycol in medical gel dressings can protect wounds, wound surface, promote wound healing, relieve pain, reduce scar formation, isolate bacteria and prevent infection. At the same time, polyethylene glycol dressings have a certain water absorption capacity, which can keep the wound surface moist and promote healing.

[0014] Preferably, in step S1, the mass ratio of nano-titanium dioxide, anhydrous ethanol and γ-glycidyloxypropyltrimethoxysilane is 100:1500-1800:45-65.

[0015] Preferably, in step S1, the reaction temperature is 65-75° C., and the reaction time is 12-18 h.

[0016] Preferably, in step S2, the mass ratio of epoxidized titanium dioxide, deionized water and polyhexamethylene biguanide is 100:4000-4800:210-250.

[0017] Preferably, in step S2, the reaction temperature is 25-35° C., and the reaction time is 24-36 h.

[0018] Preferably, in step S3, the mass ratio of amino-modified titanium dioxide, deionized water, sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:5000-5500:90-105:82-100:72-86.

[0019] Preferably, in step S3, the reaction temperature is 25-35° C., and the reaction time is 18-24 h.

[0020] Preferably, in step S4, the mass ratio of gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate is 2-3:100:0.5-1.2:1.5-3:1.2-2.

[0021] Preferably, in step S4, the stirring temperature is 50-55°C.

[0022] The present invention also provides a nano medical gel dressing prepared by the preparation method.

[0023] The beneficial effects of the present invention are: (1) Nano-titanium dioxide is added to the nano-medical gel dressing of the present invention, which has excellent antibacterial and mechanical properties. In the water and air system, the electrons of nano-titanium dioxide are excited from the valence band to the conduction band, and corresponding holes are generated in the valence band to generate electron-hole pairs. Under the action of the electric field, the electrons and holes are separated and migrate to the surface of the titanium dioxide. The formed superoxide free radicals react with organic matter in the bacteria, thereby killing the bacteria and causing bacterial decomposition. The quantum size effect of nano-titanium dioxide has a very fast migration speed and a fast sterilization speed. The guanidine group on polyhexamethylene guanidine has good biocompatibility, similar to the structure of natural antibacterial peptides. After the guanidine group is protonated, it obtains a positive charge and can adsorb and bind to various negatively charged bacteria, viruses and other microorganisms, and form hydrogen bonds with phosphates on bacteria, destroying the structure of bacterial cells and causing bacterial death. After the nano-titanium dioxide is modified, the agglomeration of nano-titanium dioxide is avoided. At the same time, the antibacterial efficiency and durability are improved through the synergistic antibacterial effect between the nano-titanium dioxide and the polyhexamethylene guanidine, thereby achieving the purpose of rapid sterilization.

[0024] (2) The present invention uses gelatin, modified titanium dioxide, polyethylene glycol, and sodium alginate as raw materials to obtain medical dressing gel through cross-linking. The raw materials used are non-toxic and harmless, and have good biocompatibility and degradability. The preparation process is simple and the production cost is low. The prepared gel dressing has excellent comprehensive performance. The prepared medical gel dressing can form a thin film covering the wound surface, play a physical protective role, reduce the external stimulation of the wound surface, provide a more suitable microenvironment for the wound, and promote cell growth and repair; sodium alginate and sodium hyaluronate both have high water absorption, and the gel dressing contains hydrophilic groups such as carboxyl, hydroxyl, amide bond, and amino group. The gelatin molecule has a three-dimensional network structure, which can be significantly swollen by water but not dissolved in water; the amino group and carboxyl group on the gelatin molecule generate electrostatic interaction with the carboxyl group of sodium alginate and the carboxyl group on the modified titanium dioxide, and generate hydrogen bonds with the hydroxyl group on the polyethylene glycol to form a three-dimensional network structure with good flexibility and good structural stability, excellent water absorption and storage effect, and good drug loading capacity. At the same time, the overall density of the gel is increased, the polymer entanglement is tighter, the compression strength is improved, and the tensile strength and elongation at break are improved, and the mechanical properties are excellent; the nano medical gel prepared by the present invention is not easy to adhere to the wound during the dressing change, thereby avoiding the secondary damage caused by the tearing of the wound.

[0025] (3) The nano medical gel prepared by the present invention has a high swelling ratio and excellent ability to absorb and store water. It can quickly and massively absorb exudate from the wound and keep the wound clean and dry. The present invention is particularly important in treating wounds with a large amount of exudate. By absorbing the exudate, the dressing can reduce the risk of wound infection and promote wound healing. After absorbing the exudate, the dressing will form a layer of gel-like substance, which can serve as a natural physical barrier to effectively block the invasion of external bacteria. Furthermore, the dressing can fit the wound bed, minimize the dead corners for bacterial reproduction, lock the bacteria in the exudate, inhibit bacterial reproduction, and prevent wound infection. DETAILED DESCRIPTION

[0026] The technical scheme of the present invention is further specifically described below through examples, which are provided for the purpose of illustrating the present invention and are not intended to limit the present invention. Based on the examples in this application, all other examples obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0027] The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0028] Example 1 A method for preparing a nano medical gel dressing comprises the following steps: S1. Disperse nano titanium dioxide in anhydrous ethanol, and after uniform dispersion, add γ-glycidyloxypropyltrimethoxysilane, wherein the mass ratio of nano titanium dioxide, anhydrous ethanol and γ-glycidyloxypropyltrimethoxysilane is 100:1500:45, mix, heat, react at 65°C in a nitrogen atmosphere for 18 hours, filter after the reaction, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain epoxidized titanium dioxide; S2, ultrasonically dispersing epoxidized titanium dioxide into deionized water, adding polyhexamethylene biguanide, stirring and mixing, wherein the mass ratio of epoxidized titanium dioxide, deionized water, and polyhexamethylene biguanide is 100:4000:210, reacting at 25°C for 36 hours, filtering after the reaction, washing with deionized water, and drying at 60°C for 24 hours to obtain amino-modified titanium dioxide; S3, ultrasonically dispersing amino-modified titanium dioxide into deionized water, adding sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, wherein the mass ratio of amino-modified titanium dioxide, deionized water, sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:5500:105:100:86, stirring and mixing, reacting at 35°C for 18 hours, filtering after the reaction, and freeze-drying to obtain modified titanium dioxide; S4. Stir gelatin and deionized water for 1 hour at a stirring temperature of 50°C. After mixing evenly, add polyethylene glycol, modified titanium dioxide and sodium alginate, wherein the mass ratio of gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate is 2:100:0.5:1.5:1.2. Stir and mix for 2 hours. After stirring and mixing, let stand for 12 hours and sterilize to obtain a nano medical gel dressing.

[0029] Example 2 A method for preparing a nano medical gel dressing comprises the following steps: S1. Disperse nano titanium dioxide in anhydrous ethanol, and after uniform dispersion, add γ-glycidyloxypropyltrimethoxysilane, wherein the mass ratio of nano titanium dioxide, anhydrous ethanol and γ-glycidyloxypropyltrimethoxysilane is 100:1650:55, mix, heat, react at 70°C in a nitrogen atmosphere for 15 hours, filter after the reaction, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain epoxidized titanium dioxide; S2, ultrasonically dispersing epoxidized titanium dioxide into deionized water, adding polyhexamethylene biguanide, stirring and mixing, wherein the mass ratio of epoxidized titanium dioxide, deionized water, and polyhexamethylene biguanide is 100:4200:225, reacting at 30°C for 32 hours, filtering after the reaction, washing with deionized water, and drying at 60°C for 24 hours to obtain amino-modified titanium dioxide; S3, ultrasonically dispersing amino-modified titanium dioxide into deionized water, adding sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, wherein the mass ratio of amino-modified titanium dioxide, deionized water, sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:5200:95:90:78, stirring and mixing, reacting at 30°C for 20 hours, filtering after the reaction, and freeze-drying to obtain modified titanium dioxide; S4. Stir gelatin and deionized water for 1 hour at a stirring temperature of 52°C. After mixing evenly, add polyethylene glycol, modified titanium dioxide and sodium alginate, wherein the mass ratio of gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate is 2.4:100:0.8:2:1.5. Stir and mix for 3 hours. After stirring and mixing, let stand for 12 hours and sterilize to obtain a nano medical gel dressing.

[0030] Example 3 A method for preparing a nano medical gel dressing comprises the following steps: S1. Disperse nano titanium dioxide in anhydrous ethanol, and after uniform dispersion, add γ-glycidyloxypropyltrimethoxysilane, wherein the mass ratio of nano titanium dioxide, anhydrous ethanol and γ-glycidyloxypropyltrimethoxysilane is 100:1650:55, mix, heat, react at 70°C in a nitrogen atmosphere for 15 hours, filter after the reaction, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain epoxidized titanium dioxide; S2, ultrasonically dispersing epoxidized titanium dioxide into deionized water, adding polyhexamethylene biguanide, stirring and mixing, wherein the mass ratio of epoxidized titanium dioxide, deionized water and polyhexamethylene biguanide is 100:4600:240, reacting at 30°C for 35 hours, filtering after the reaction, washing with deionized water, and drying at 60°C for 24 hours to obtain amino-modified titanium dioxide; S3, ultrasonically dispersing amino-modified titanium dioxide into deionized water, adding sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, wherein the mass ratio of amino-modified titanium dioxide, deionized water, sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:5400:102:95:82, stirring and mixing, reacting at 30°C for 22 hours, filtering after the reaction, and freeze-drying to obtain modified titanium dioxide; S4. Stir gelatin and deionized water for 1 hour at a stirring temperature of 52°C. After mixing evenly, add polyethylene glycol, modified titanium dioxide and sodium alginate, wherein the mass ratio of gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate is 2.8:100:1:2.5:1.8. Stir and mix for 3.5 hours. After stirring and mixing, let stand for 12 hours and sterilize to obtain a nano medical gel dressing.

[0031] Example 4 A method for preparing a nano medical gel dressing comprises the following steps: S1. Disperse nano titanium dioxide in anhydrous ethanol, and after uniform dispersion, add γ-glycidyloxypropyltrimethoxysilane, wherein the mass ratio of nano titanium dioxide, anhydrous ethanol and γ-glycidyloxypropyltrimethoxysilane is 100:1800:65, mix, heat, react at 75°C in a nitrogen atmosphere for 12 hours, filter after the reaction, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain epoxidized titanium dioxide; S2, ultrasonically dispersing epoxidized titanium dioxide into deionized water, adding polyhexamethylene biguanide, stirring and mixing, wherein the mass ratio of epoxidized titanium dioxide, deionized water, and polyhexamethylene biguanide is 100:4800:250, reacting at 35°C for 24 hours, filtering after the reaction, washing with deionized water, and drying at 60°C for 24 hours to obtain amino-modified titanium dioxide; S3, ultrasonically dispersing amino-modified titanium dioxide into deionized water, adding sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, wherein the mass ratio of amino-modified titanium dioxide, deionized water, sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:5500:105:100:86, stirring and mixing, reacting at 35° C. for 18 hours, filtering after the reaction, and freeze-drying to obtain modified titanium dioxide; S4. Stir gelatin and deionized water for 1 hour at a stirring temperature of 55°C. After mixing evenly, add polyethylene glycol, modified titanium dioxide and sodium alginate, wherein the mass ratio of gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate is 3:100:1.2:3:2. Stir and mix for 4 hours. After stirring and mixing, let stand for 12 hours and sterilize to obtain a nanomedical gel dressing.

[0032] Comparative Example 1 A method for preparing a medical gel dressing comprises the following steps: S1. Disperse nano titanium dioxide in anhydrous ethanol. After uniform dispersion, add γ-aminopropyltriethoxysilane, wherein the mass ratio of nano titanium dioxide, anhydrous ethanol and γ-aminopropyltriethoxysilane is 100:1650:55. Mix, heat up, react at 70°C in a nitrogen atmosphere for 15 hours. After the reaction is completed, filter, wash with deionized water, and vacuum dry at 60°C for 12 hours to obtain amino titanium dioxide. S2, ultrasonically dispersing amino-modified titanium dioxide into deionized water, adding sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, wherein the mass ratio of amino-modified titanium dioxide, deionized water, sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:5400:102:95:82, stirring and mixing, reacting at 30°C for 22 hours, filtering after the reaction, and freeze-drying to obtain modified titanium dioxide; S3. Stir gelatin and deionized water for 1 hour at a stirring temperature of 52°C. After mixing evenly, add polyethylene glycol, modified titanium dioxide and sodium alginate, wherein the mass ratio of gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate is 2.8:100:1:2.5:1.8. Stir and mix for 3.5 hours. After stirring and mixing, let stand for 12 hours and sterilize to obtain a medical gel dressing.

[0033] Comparative Example 2 A method for preparing a medical gel dressing comprises the following steps: S1. Stir gelatin and deionized water for 1 hour at a stirring temperature of 52°C. After mixing evenly, add polyethylene glycol, nano-titanium dioxide, polyhexamethylene biguanide and sodium alginate, wherein the mass ratio of gelatin, deionized water, polyethylene glycol, nano-titanium dioxide, polyhexamethylene biguanide and sodium alginate is 2.8:100:1:0.7:1.8:1.8. Stir and mix for 3.5 hours. After stirring and mixing, let stand for 12 hours and sterilize to obtain a medical gel dressing.

[0034] The nano titanium dioxide in the examples and comparative examples of the present invention was purchased from Xuancheng Jingrui New Materials Co., Ltd., model JR05, with an average particle size of 5 nm; sodium alginate and sodium hyaluronate were purchased from Shanghai McLean Biochemical Technology Co., Ltd.; polyethylene glycol was purchased from Nantong Jiaxian International Trade Co., Ltd.; other undisclosed reagents were commercially available.

[0035] The medical gel dressings prepared in Examples 1-4 and Comparative Examples 1-2 were used as samples, respectively recorded as Samples 1-6, and the samples were subjected to corresponding tests. The test methods and test results are as follows: (1) Mechanical properties test 1) Compression strength test: At room temperature, a 20 mm diameter and 5 mm high cylindrical gel was prepared using a twelve-well plate. The sample was subjected to compression test using a physical property analyzer until it broke. The compression rate was set to 0.5 mm / s. The compression test was repeated five times for each group of samples. 2) Cut the sample into a dumbbell shape with a cutter. The total length of the sample is 75 cm, the length of the test part is 40 mm, and the width is 4 mm. Clamp the upper and lower ends of the sample on the tensile testing machine and stretch it at a tensile speed of 100 mm / min. Measure the tensile strength and elongation at break. Test each sample three times and take the average value. (2) Swelling performance test: Place the sample in a vacuum freeze dryer and dry it to constant weight. Take a dry gel disc of similar size and mass, record the mass as M0, soak the dried gel disc in deionized water, take it out at regular intervals, wipe off the surface moisture and weigh it. The mass at this time is recorded as Mt. Calculate the swelling ratio SR. The swelling ratio is calculated as follows: SR = (Mt-M0) / Mt×100%, where M0 and Mt are the masses of the dry gel and the hydrogel at time t, respectively. (3) Antibacterial performance test: 0.1 g of the sample was mixed with 10 mL of 1×107 CFU / mL Escherichia coli and Staphylococcus aureus respectively and placed in a test tube. The mixture was placed on a constant temperature incubator shaker at 37°C and 120 r / min for 4 h, and then incubated in an oscillating incubator under natural light conditions for 24 h. The inhibition rate was calculated by the plate colony counting method. The inhibition rate was calculated as follows: inhibition rate = (M1-M2) / M1×100%, where M1 and M2 are the initial colony count and the colony count after incubation, respectively. The above test results are shown in Table 1: Table 1

[0036] According to the test results in Table 1, the medical gel dressings prepared in Examples 1-4 have excellent mechanical properties, swelling properties and antibacterial properties. In Comparative Example 1, the nano-titanium dioxide is directly aminated to obtain aminated titanium dioxide, and the aminated titanium dioxide reacts with sodium hyaluronate to obtain modified titanium dioxide, which is then mixed with gelatin, polyethylene glycol, and sodium alginate to obtain a medical gel dressing. Polyhexamethylene biguanide is not introduced, and the antibacterial properties are greatly reduced, and the mechanical properties and swelling ratio are reduced. In Comparative Example 2, the nano-titanium dioxide is not modified, the dispersibility of the nano-titanium dioxide is greatly reduced, the compatibility with the raw materials is deteriorated, the cross-linking degree is deteriorated, and the comprehensive performance of the prepared medical gel dressing is greatly reduced.

[0037] The present invention uses gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate as raw materials, mixes them, and obtains medical dressing gel by cross-linking. The raw materials used in the present invention are non-toxic and harmless, have good biocompatibility, can form a thin film to cover the wound surface, play a physical protective role, reduce the wound surface from external stimulation, and then promote tissue repair, the formed three-dimensional network structure has good stability, has excellent water absorption and storage effects, and has strong drug loading capacity. Nano titanium dioxide and polyhexamethylene guanidine have a synergistic antibacterial effect, improve the antibacterial efficiency and durability, and achieve the purpose of rapid sterilization. At the same time, the overall density of the gel is increased, the polymer entanglement is more compact, the compression strength is improved, and the tensile strength and elongation at break are improved, and the mechanical properties are excellent.

[0038] Finally, it should be noted that although the embodiments of the present invention have been shown and described, it is understandable to those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and all equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for preparing a nano medical gel dressing, characterized in that The steps include: S1. Disperse nano titanium dioxide in anhydrous ethanol, and after the dispersion is uniform, add γ-glycidyloxypropyltrimethoxysilane, mix, heat, and react in a nitrogen atmosphere. After the reaction is completed, filter, wash, and vacuum dry to obtain epoxidized titanium dioxide; S2, ultrasonically dispersing epoxidized titanium dioxide into deionized water, adding polyhexamethylene biguanide, stirring and mixing, reacting, filtering, washing, and drying after the reaction is completed to obtain amino-modified titanium dioxide; S3, ultrasonically dispersing amino-modified titanium dioxide into deionized water, adding sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, stirring and mixing, reacting, filtering and freeze-drying after the reaction to obtain modified titanium dioxide; S4. Stir and mix gelatin and deionized water. After mixing evenly, add polyethylene glycol, modified titanium dioxide and sodium alginate. After mixing, let stand and sterilize to obtain a nano medical gel dressing.

2. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In the step S1, the mass ratio of nano titanium dioxide, anhydrous ethanol and γ-glycidyloxypropyltrimethoxysilane is 100:1500-1800:45-65.

3. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In the step S1, the reaction temperature is 65-75° C., and the reaction time is 12-18 hours.

4. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In the step S2, the mass ratio of epoxidized titanium dioxide, deionized water and polyhexamethylene biguanide is 100:4000-4800:210-250.

5. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In step S2, the reaction temperature is 25-35° C., and the reaction time is 24-36 hours.

6. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In the step S3, the mass ratio of amino-modified titanium dioxide, deionized water, sodium hyaluronate, 1-ethyl (-3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 100:5000-5500:90-105:82-100:72-86.

7. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In step S3, the reaction temperature is 25-35° C., and the reaction time is 18-24 hours.

8. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In step S4, the mass ratio of gelatin, deionized water, polyethylene glycol, modified titanium dioxide and sodium alginate is 2-3:100:0.5-1.2:1.5-3:1.2-2.

9. The method for preparing the nano medical gel dressing according to claim 1, characterized in that: In the step S4, the stirring temperature is 50-55°C.

10. A nano medical gel dressing prepared by the method according to any one of claims 1 to 9.

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