A medical dressing for wounds and its preparation method

Abstract

This invention belongs to the field of medical dressing technology, specifically relating to a medical dressing for wounds and its preparation method. The medical dressing for wounds of this invention, by weight percentage, consists of the following raw materials: 6-12% polyvinyl alcohol, 3-5% carboxymethyl chitosan, 0.1-0.3% lipid extract, 0.5-1% curculigoside, 0.1-0.5% glycerin, 0.01-0.05% vitamin E, with the balance being deionized water. The addition of lipid extract and curculigoside to the medical dressing for wounds of this invention, when used in combination, can improve the dressing's exudate absorption capacity and significantly improve the healing quality of the wound. The porous carrier added to the lipid extract not only enhances the antioxidant activity of the lipid extract but also facilitates the diffusion and absorption of wound exudate, provides a scaffold for cell adhesion and proliferation, promotes epidermal cell and blood vessel regeneration, and accelerates the wound healing process.

Description

Technical Field

[0001] This invention belongs to the field of medical dressing technology, specifically relating to a medical dressing for wounds and its preparation method. Background Technology

[0002] Human skin is an important component of the immune system, playing a vital role in protecting against external environmental factors and viruses / microorganisms. Composed of the epidermis, dermis, and subcutaneous tissue, skin performs various functions within the body, including regulating body temperature, defending against toxins and pathogens, and immune regulation. However, skin is also one of the most vulnerable parts of the body, frequently susceptible to external damage. Skin wounds are classified as acute or chronic. Acute wounds heal quickly, while chronic wounds take longer to heal. A prime example of a chronic wound is a diabetic wound. The core reason diabetic wounds are difficult to heal is that the high-sugar environment damages microvessels and the immune system. Once a wound develops, it easily leads to bacterial growth, chronic inflammation, wound infection, and other risks, hindering healing.

[0003] Medical dressings typically function by covering the wound to stop bleeding, prevent external infection and damage, and thus promote wound healing. Traditional medical dressings include sterile gauze and medical absorbent cotton, which are widely available and inexpensive. However, they also have certain drawbacks. For example, they only provide physical isolation and protection, and their ability to absorb exudate is limited. Once soaked with exudate, they lose their protective function. Furthermore, due to their limited functionality, their ability to promote wound healing is poor, and changing dressings can easily cause secondary damage to the wound, thereby increasing the risk of infection.

[0004] In order to overcome the shortcomings of traditional medical dressings, there is an urgent need to develop a medical dressing for wounds that can effectively absorb exudate and promote wound healing. Summary of the Invention

[0005] The primary objective of this invention is to provide a medical dressing for use on wound surfaces.

[0006] A second objective of this invention is to provide a method for preparing a medical dressing for wounds.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A medical dressing for wound application, comprising, by weight percentage, the following raw materials: 6-12% polyvinyl alcohol, 3-5% carboxymethyl chitosan, 0.1-0.3% lipid extract, 0.5-1% curculigoside, 0.1-0.5% glycerin, 0.01-0.05% vitamin E, with the balance being water.

[0009] Furthermore, the preparation process of the lipid extract is as follows: Bifidobacterium longum powder is added to PBS buffer and sonicated, then a mixed solvent of chloroform and methanol is added, the mixture is allowed to stand, centrifuged, the precipitate is collected, washed, added to a porous carrier, and freeze-dried to obtain the lipid extract.

[0010] Furthermore, the preparation process of the porous carrier is as follows: corn cobs are washed, dried, and crushed, then added to an aqueous solution of acetic acid, heated to react, and then zinc chloride is added for aging. After aging, the mixture is filtered, washed, and dried to obtain the porous carrier.

[0011] Furthermore, the activity of Bifidobacterium longum in the Bifidobacterium longum powder is (1-5) × 10⁻⁶. 8 CFU / g; the ultrasonic disruption power is 100-200w, the time is 3-5min, and the mass ratio of the Bifidobacterium longum powder to PBS buffer is 1:15-20.

[0012] Further, the mass ratio of the corn cob, the acetic acid aqueous solution, and the zinc chloride is 1:(80-100):(0.2-0.5); the volume concentration of the acetic acid aqueous solution is 2%-10%.

[0013] Furthermore, the heating reaction is carried out at a temperature of 80-90℃ for 3-5 hours; the aging process is carried out at a temperature of 40-50℃ for 5-10 hours.

[0014] Furthermore, the activity of Bifidobacterium longum in the Bifidobacterium longum powder is (1-5) × 10⁻⁶. 8 CFU / g; the ultrasonic power is 100-200w, and the time is 3-5min; the mass ratio of Bifidobacterium longum powder to PBS buffer is 1:15-20.

[0015] Further, the mixed solvent is prepared by mixing chloroform and methanol at a volume ratio of 1:0.3-0.8, and the volume ratio of the PBS buffer to the mixed solvent is 1:(7-10); the standing temperature is 4-6℃ and the time is 1-3h.

[0016] Furthermore, the mass ratio of the precipitate to the porous carrier is 1:(0.1-0.3).

[0017] The preparation method of the above-mentioned medical dressing for wounds includes the following steps:

[0018] (1) Weigh each raw material component according to its mass percentage and set aside;

[0019] (2) Mix carboxymethyl chitosan, polyvinyl alcohol and water in half the mass, stir, and obtain component A;

[0020] (3) Add the lipid extract, curculigoside, glycerol, and vitamin E to the remaining water and stir to obtain component B;

[0021] (4) Mix component A and component B, stir and then sterilize by irradiation.

[0022] Furthermore, the irradiation sterilization is gamma-ray irradiation sterilization or electron beam irradiation sterilization.

[0023] Compared with the prior art, the main advantages of the present invention are:

[0024] 1. This invention provides a novel medical dressing formulation for wound treatment. The addition of lipid extracts and curculigoside significantly improves wound healing quality, enhances cellular antioxidant capacity, and promotes wound healing. The porous carrier added to the lipid extract enhances its antioxidant activity and, through its porous structure, facilitates the diffusion and absorption of wound exudate, providing a scaffold for cell adhesion and proliferation, promoting epidermal cell and angiogenesis, and accelerating wound healing. Furthermore, the cross-linking between the porous carrier and the dressing matrix improves the dressing's mechanical properties. The hydroxyl groups in curculigoside can form electrostatic and hydrogen bonds with the amino and carboxyl groups on carboxymethyl chitosan, improving the stability of curculigoside in the dressing matrix. In addition, the interaction between curculigoside and the dressing matrix enhances the dressing matrix's extensibility, further improving the dressing's exudate absorption capacity, preventing exudate backflow, and accelerating the wound healing process.

[0025] 2. The present invention provides a method for preparing medical dressings for wounds, which is simple and efficient and conducive to clinical application. Attached Figure Description

[0026] Figure 1 This is an electron microscope image of the porous carrier obtained in Embodiment 1 of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will be further described below with reference to specific embodiments. However, those skilled in the art should understand that the following embodiments are only for illustrating the present invention and should not be regarded as limiting the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the reagents or instruments used are all conventional products obtained through commercial channels.

[0028] Example 1

[0029] A medical dressing for wound application, comprising, by weight percentage, the following raw materials: 10% polyvinyl alcohol, 4% carboxymethyl chitosan, 0.2% lipid extract, 0.8% curculigoside, 0.3% glycerin, 0.03% vitamin E, with the balance being deionized water.

[0030] The preparation process of the porous support is as follows: An acetic acid aqueous solution with a volume concentration of 8% was prepared; corn cobs were washed, dried, and pulverized, then added to the acetic acid aqueous solution and heated at 85°C for 4 hours; zinc chloride was then added, with the mass ratio of corn cobs, acetic acid aqueous solution, and zinc chloride being 1:90:0.4; the mixture was aged at 45°C for 7 hours; after aging, it was filtered, washed, and dried to obtain the porous support. The electron micrograph of the porous support is shown below. Figure 1 As shown.

[0031] The preparation process of the lipid extract is as follows:

[0032] Bifidobacterium longum (CICC6068) was inoculated into MRS liquid medium and cultured. The resulting culture solution was freeze-dried to obtain Bifidobacterium longum powder. The viable count of Bifidobacterium longum in the obtained Bifidobacterium longum powder was 5 × 10⁻⁶. 8 CFU / g;

[0033] Bifidobacterium longum powder was added to PBS buffer and sonicated at 150W for 4 min. The mass ratio of Bifidobacterium longum powder to PBS buffer was 1:18. A mixed solvent of chloroform and methanol (prepared by mixing chloroform and methanol at a volume ratio of 1:0.5) was then added. The volume ratio of PBS buffer to the mixed solvent was 1:8. The mixture was allowed to stand at 5℃ for 2 h, centrifuged, and the precipitate was collected. It was washed directly with methanol, and then a porous carrier was added. The mass ratio of precipitate to porous carrier was 1:0.2. The lipid extract was obtained by freeze-drying.

[0034] Example 1 also provides a method for preparing a medical dressing for wounds, as follows:

[0035] (1) Weigh each raw material component according to its mass percentage and set aside;

[0036] (2) Add carboxymethyl chitosan and polyvinyl alcohol to half the mass of water and stir at 60 rpm for 50 min to obtain component A;

[0037] (3) Add lipid extract, curculigoside, glycerol and vitamin E to the remaining water and stir at 60 rpm for 50 min to obtain component B;

[0038] (4) Mix component A and component B, stir at 90 rpm for 30 min, and sterilize by electron beam irradiation.

[0039] Example 2

[0040] A medical dressing for wound application, comprising, by weight percentage, the following raw materials: 6% polyvinyl alcohol, 3% carboxymethyl chitosan, 0.1% lipid extract, 0.5% curculigoside, 0.1% glycerin, 0.01% vitamin E, with the balance being deionized water.

[0041] The preparation process of the porous carrier is as follows: Prepare an acetic acid aqueous solution with a volume concentration of 3%; wash, dry and crush the corn cob, then add it to the acetic acid aqueous solution, heat at 80℃ for 5 hours, then add zinc chloride, the mass ratio of corn cob, acetic acid aqueous solution and zinc chloride is 1:80:0.2; age at 40℃ for 10 hours, after aging, filter, wash and dry to obtain the porous carrier.

[0042] The preparation process of the lipid extract is as follows:

[0043] Bifidobacterium longum was inoculated into MRS liquid medium and cultured. The resulting culture solution was freeze-dried to obtain Bifidobacterium longum powder. The viable count of Bifidobacterium longum in the Bifidobacterium longum powder was 1×10⁻⁶. 8 CFU / g;

[0044] Bifidobacterium longum powder was added to PBS buffer and sonicated at 100W for 5 min. The mass ratio of Bifidobacterium longum powder to PBS buffer was 1:15. A mixed solvent of chloroform and methanol (prepared by mixing chloroform and methanol at a volume ratio of 1:0.3) was then added. The volume ratio of PBS buffer to the mixed solvent was 1:7. The mixture was allowed to stand at 4℃ for 3 h, centrifuged, and the precipitate was collected. The precipitate was washed directly with methanol, and then a porous carrier was added. The mass ratio of the precipitate to the porous carrier was 1:0.1. The lipid extract was obtained by freeze-drying.

[0045] Example 2 also provides a method for preparing a medical dressing for wounds, as follows:

[0046] (1) Weigh each raw material component according to its mass percentage and set aside;

[0047] (2) Add carboxymethyl chitosan and polyvinyl alcohol to half the mass of water and stir at 60 rpm for 50 min to obtain component A;

[0048] (3) Add lipid extract, curculigoside, glycerol and vitamin E to the remaining water and stir at 60 rpm for 50 min to obtain component B;

[0049] (4) Mix component A and component B, stir at 90 rpm for 30 min, and sterilize by electron beam irradiation.

[0050] Example 3

[0051] A medical dressing for wound application, by weight percentage, is composed of the following raw materials: 12% polyvinyl alcohol, 5% carboxymethyl chitosan, 0.3% lipid extract, 1% curculigoside, 0.5% glycerin, 0.05% vitamin E, and the balance being deionized water.

[0052] The preparation process of the porous carrier is as follows: Prepare an acetic acid aqueous solution with a volume concentration of 10%; wash, dry and crush the corn cob, then add it to the acetic acid aqueous solution, heat at 90℃ for 3 hours, then add zinc chloride, the mass ratio of corn cob, acetic acid aqueous solution and zinc chloride is 1:100:0.5; age at 50℃ for 5 hours, after aging, filter, wash and dry to obtain the porous carrier.

[0053] The preparation process of the lipid extract is as follows:

[0054] Bifidobacterium longum was inoculated into MRS liquid medium and cultured. The resulting culture solution was freeze-dried to obtain Bifidobacterium longum powder. The viable count of Bifidobacterium longum in the Bifidobacterium longum powder was 3 × 10⁻⁶. 8 CFU / g;

[0055] Bifidobacterium longum powder was added to PBS buffer and sonicated at 200W for 3 min, with a mass ratio of Bifidobacterium longum powder to PBS buffer of 1:20. A mixed solvent of chloroform and methanol (prepared at a volume ratio of 1:0.8) was then added, with a volume ratio of PBS buffer to the mixed solvent of 1:10. The mixture was allowed to stand at 6℃ for 1 h, centrifuged, and the precipitate was collected and washed directly with methanol. Then, a porous carrier was added, with a mass ratio of precipitate to porous carrier of 1:0.3. The lipid extract was obtained by freeze-drying.

[0056] Example 3 also provides a method for preparing a medical dressing for wounds, as follows:

[0057] (1) Weigh each raw material component according to its mass percentage and set aside;

[0058] (2) Add carboxymethyl chitosan and polyvinyl alcohol to half the mass of water and stir at 60 rpm for 50 min to obtain component A;

[0059] (3) Add the lipid extract, curculigoside, glycerol and vitamin E to the remaining water and stir at 60 rpm for 50 min to obtain component B;

[0060] (4) Mix component A and component B, stir at 90 rpm for 30 min, and sterilize by γ-ray irradiation.

[0061] Comparative Example 1

[0062] Comparative Example 1 is basically the same as Example 1, except that the addition of lipid extract is omitted, while everything else remains the same as Example 1.

[0063] Comparative Example 2

[0064] Comparative Example 2 is basically the same as Example 1, except that the porous carrier is omitted in the preparation of the lipid extract, while the rest is the same as Example 1.

[0065] Comparative Example 3

[0066] Comparative Example 3 is basically the same as Example 1, except that the addition of curculigoside is omitted, while everything else remains the same as Example 1.

[0067] Comparative Example 4

[0068] Comparative Example 4 is basically the same as Example 1, except that the lipid extract is replaced with curculigoside, while the rest is the same as Example 1.

[0069] Experimental Example 1

[0070] The dressings obtained in Examples 1-3 and Comparative Examples 1-4 were cut into pieces 40 mm long, 3 mm wide, and 3 mm thick. The tensile strength and elongation at break of the dressings obtained in Examples 1-3 and Comparative Examples 1-4 were tested using a universal testing machine. The constant strain rate was set to 1 mm / min, and each group was repeated 5 times. The average value was taken as the final experimental result, as shown in Table 1.

[0071] Table 1 Mechanical properties of dressings from Examples 1-3 and Comparative Examples 1-4

[0072]

[0073] As shown in Table 1, compared with Examples 1-3, Comparative Example 2 omitted the introduction of the porous carrier, Comparative Example 3 omitted the addition of curculigoside, and Comparative Example 4 omitted the lipid extract and increased the amount of curculigoside. The tensile strength and elongation at break of the dressings all showed varying degrees of decrease. Analysis indicates that the cross-linking between the porous carrier and the matrix in the dressing improves the mechanical properties of the dressing.

[0074] Experimental Example 2

[0075] According to the test method of YY / T0471.1-2004 "Test methods for contact wound dressings - Part 1: Liquid absorbability", the exudate absorption performance of the products obtained in Examples 1-3 and Comparative Examples 1-4 was tested, and the results are shown in Table 2.

[0076] Table 2. Permeability and absorption rates of dressings in Examples 1-3 and Comparative Examples 1-4

[0077]

[0078] The test results in Table 2 show that the dressings obtained in Examples 1-3 of this invention have good exudate absorption capacity and effectively prevent liquid diffusion. Compared with Examples 1-3, the permeation absorption rate of the medical dressings obtained in Comparative Examples 1-4 decreased to varying degrees. Comparative Example 1 omitted the lipid extract, Comparative Example 2 omitted the porous carrier, and Comparative Example 3 omitted curculigoside; Comparative Example 4 omitted the lipid extract and increased the amount of curculigoside. The above test results show that the combined effect of curculigoside and lipid extract in this invention can improve the exudate absorption capacity of the dressing, prevent exudate backflow, and enhance the absorbency of the dressing.

[0079] Experimental Example 3

[0080] To investigate the healing ability of the medical dressings obtained in Examples 1-3 and Comparative Examples 1-4 on wounds in diabetic rats, the following experiments were conducted:

[0081] Eight-week-old male SD rats were selected as experimental animals and acclimatized for one week with free access to water and food. They were randomly divided into seven groups of ten rats each and fed a high-sugar, high-fat diet for four consecutive weeks. Then, each rat was intraperitoneally injected with streptozotocin citrate solution (0.1M, pH 4.3) at a dose of 60 mg / kg to induce type 2 diabetes.

[0082] The type 2 diabetic rats were anesthetized with an anesthetic (Salvastatin, dose 50 mg / kg). After shaving the back hair, the rats were disinfected with 75% ethanol and povidone-iodine. A circular wound with a diameter of 1 cm was then created on the back of the rats. The wound dressings of Examples 1-3 and Comparative Examples 1-4 were used to cover the wounds. The wounds were photographed on day 16 using a digital camera, and the wound area was calculated using ImageJ software. The wound healing rate (unit: %) was calculated according to the following formula. The results are shown in Table 3.

[0083] Wound healing rate = (initial wound area - post-treatment wound area) / initial wound area × 100%.

[0084] Table 3. Wound healing rates of dressings used in Examples 1-3 and Comparative Examples 1-4

[0085]

[0086] As shown in Table 3, the medical dressings of Examples 1-3 of this invention have a better effect on promoting the healing of diabetic wounds. Compared with Example 1, the medical dressings of Comparative Examples 1-4 have a poorer effect on wound healing. Further analysis shows that Comparative Example 1 omitted the lipid extract, and Comparative Example 2 omitted the porous carrier, indicating that the introduction of the porous carrier can improve the antioxidant activity of the lipid extract and reduce wound fluid exudation, thereby promoting wound healing. The experimental results of Comparative Examples 3 and 4 show that curculigoside promotes rapid wound healing by improving the exudate absorption capacity of the dressing and preventing exudate backflow.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A medical dressing for use on wound surfaces, characterized in that, It is composed of the following raw materials by mass percentage: 6-12% polyvinyl alcohol, 3-5% carboxymethyl chitosan, 0.1-0.3% lipid extract, 0.5-1% curculigoside, 0.1-0.5% glycerin, 0.01-0.05% vitamin E, and the balance being water; The preparation process of the lipid extract is as follows: Take Bifidobacterium longum powder, add it to PBS buffer and sonicate, then add a mixed solvent of chloroform and methanol, let it stand, centrifuge, collect the precipitate, wash it, add it to a porous carrier, and freeze dry to obtain the lipid extract. The preparation process of the porous carrier is as follows: corn cobs are washed, dried and crushed, then added to an aqueous solution of acetic acid, heated and reacted, and then zinc chloride is added for aging. After aging, the mixture is filtered, washed and dried to obtain the porous carrier.

2. The medical dressing for wounds according to claim 1, characterized in that, The mass ratio of the corn cob, acetic acid aqueous solution, and zinc chloride is 1:(80-100):(0.2-0.5); the volume concentration of the acetic acid aqueous solution is 2%-10%.

3. The medical dressing for wounds according to claim 1, characterized in that, The heating reaction is carried out at a temperature of 80-90℃ for 3-5 hours; the aging process is carried out at a temperature of 40-50℃ for 5-10 hours.

4. The medical dressing for wounds according to claim 1, characterized in that, The activity of Bifidobacterium longum in the Bifidobacterium longum powder is (1-5)×10. 8 CFU / g; the ultrasonic power is 100-200w, and the time is 3-5min; the mass ratio of Bifidobacterium longum powder to PBS buffer is 1:(15-20).

5. The medical dressing for wounds according to claim 1, characterized in that, The mixed solvent is prepared by mixing chloroform and methanol at a volume ratio of 1:(0.3-0.8), and the volume ratio of the PBS buffer to the mixed solvent is 1:(7-10); the standing temperature is 4-6℃ and the time is 1-3h.

6. The medical dressing for wounds according to claim 1, characterized in that, The mass ratio of the precipitate to the porous support is 1:(0.1-0.3).

7. The method for preparing a medical dressing for wounds according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Weigh each raw material component according to its mass percentage and set aside; (2) Mix carboxymethyl chitosan, polyvinyl alcohol and water in half the mass, stir, and obtain component A; (3) Add the lipid extract, curculigoside, glycerol, and vitamin E to the remaining water and stir to obtain component B; (4) Mix component A and component B, stir and then sterilize by irradiation.

8. The method for preparing a medical dressing for wounds according to claim 7, characterized in that, The irradiation sterilization is either gamma-ray irradiation sterilization or electron beam irradiation sterilization.

Images