A medical dressing for promoting the healing of diabetic wounds and its preparation method

Abstract

The present invention relates to the field of medical technology, and particularly to a medical dressing for promoting the healing of diabetic wounds and a preparation method thereof. The medical dressing for promoting the healing of diabetic wounds comprises the following raw materials in terms of mass percentage: 0.008-0.012% of stem cell exosomes, 0.002-0.005% of oligopeptide-1, 0.004-0.01% of jasminin, 0.03-0.07% of modified CaSi2 nanosheets, 2-6% of hydroxypropyl chitosan, 0.1-0.5% of xanthan gum, 0.5-5% of glycerol, and the balance being water. This medical dressing can not only promote wound healing, but also facilitate the repair of scars after wound healing.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and particularly to a medical dressing for promoting the healing of diabetic wounds and a preparation method thereof. Background Art

[0002] The acute or chronic wound healing of diabetes is slow, which is prone to cause various complications, imposing a heavy burden on patients, the medical system and social economy. Due to the easy occurrence of vascular lesions in diabetic patients, the regeneration of blood vessels is damaged, which in turn leads to the obstruction of cell proliferation and the synthesis and remodeling of the extracellular matrix, and finally results in the formation of chronic non-healing wounds. Promoting angiogenesis is considered to be one of the key factors in the treatment of diabetic wounds.

[0003] Exosomes are double-layer lipid vesicles with a diameter of 30-150 nm secreted by cells through the multivesicular body pathway, containing various bioactive molecules such as proteins, microRNAs, and long non-coding RNAs, and playing an important role in intercellular material transport and signal communication. Stem cell exosomes can promote the proliferation, migration and microtubule formation of endothelial cells, and thus stimulate angiogenesis. However, there are problems of reduced stability and activity after the addition of stem cell exosomes to the dressing, which limits their application in medical dressings. In addition, the characteristics of difficult-to-heal diabetic wounds often lead to the easier formation of scars after wound healing, affecting the beauty of the skin, and the existing dressings cannot well reduce the formation of scars at diabetic wound sites. Therefore, it is necessary to improve the existing dressings to solve the above problems. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, one of the purposes of the present invention is to provide a medical dressing for promoting the healing of diabetic wounds, which can not only promote wound healing but also be beneficial to the repair of scars after wound healing.

[0005] Another purpose of the present invention is to provide a preparation method of a medical dressing for promoting the healing of diabetic wounds, and the steps are simple and easy to operate.

[0006] One of the purposes of the present invention is realized by adopting the following technical solution:

[0007] A medical dressing for promoting the healing of diabetic wounds, calculated by mass percentage, comprises the following raw materials: stem cell exosomes 0.008-0.012%, oligopeptide-1 0.002-0.005%, jasminin 0.004-0.01%, modified CaSi 2 nano-sheets 0.03-0.07%, hydroxypropyl chitosan 2-6%, xanthan gum 0.1-0.5%, glycerol 0.5-5%, and the balance is water.

[0008] Further, the preparation process of the modified CaSi 2 nano-sheets is as follows:

[0009] Add CaSi 2 nanosheets to the phytic acid solution for reaction. After the reaction is completed, it is purified to obtain the product.

[0010] Further, the dosage ratio of the CaSi 2 nanosheets to the phytic acid solution is 1 g : (180 - 200) mL; the concentration of the phytic acid solution is 0.4 - 0.5 mol / L.

[0011] Further, the temperature of the reaction is 35 - 45 °C, and the reaction time is 0.5 - 1.5 h.

[0012] Further, the preparation process of the CaSi 2 nanosheets is as follows: Disperse CaSi 2 powder in N - methyl - 2 - pyrrolidone, perform probe sonication under ice - bath conditions, collect the precipitate, wash and dry it to obtain the product.

[0013] Further, the dosage ratio of the CaSi 2 powder to N - methyl - 2 - pyrrolidone is 1 g : (45 - 55) mL; the time of probe sonication is 10 - 12 h.

[0014] Further, the stem cell exosomes are umbilical cord mesenchymal stem cell exosomes.

[0015] Further, the method for obtaining the umbilical cord mesenchymal stem cell exosomes is as follows:

[0016] Inoculate passage 3 - 5 umbilical cord mesenchymal stem cells into the culture medium at a density of (0.5 - 3.5)×10 4 cells / mL for culture, obtain the supernatant, perform ultra - centrifugation to obtain the precipitate, and then freeze - dry it to obtain the product.

[0017] Further, the culture medium consists of DMEM / F12 basal medium and the following components added to the medium: 5 - 10% FBS, 25 - 40 ng / mL IL - 21, 1 - 3 ng / mL EGF.

[0018] Further, the culture time is 2 - 3 d, and the culture conditions are 37 °C and 5% CO 2 .

[0019] The second object of the present invention is achieved by the following technical solution:

[0020] The preparation method of the above - mentioned medical dressing for promoting diabetic wound healing includes the following steps:

[0021] (1)According to the mass percentage ratio, hydroxypropyl chitosan and xanthan gum are added to water. After stirring until completely dissolved, glycerol is added, and after mixing evenly, a gel matrix is obtained;

[0022] (2)According to the mass percentage ratio, oligopeptide-1, jasminin, stem cell exosomes and modified CaSi 2 nanosheets are added to the gel matrix in step (1) and mixed evenly, then it is done.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The medical dressing of the present invention adds components such as modified CaSi 2 nanosheets. The test results show that the modified CaSi 2 nanosheets obtained by the present invention can promote wound healing. Specifically, in the modification process of CaSi 2 nanosheets, the chelating property of phytic acid is utilized, so that calcium ions in the CaSi 2 nanosheets are dissolved out, while the complete silicon-based skeleton is retained, making the modified CaSi 2 nanosheets capable of enhancing the stability and pro-angiogenic activity of stem cell exosomes, thereby improving the impaired angiogenesis in diabetic wounds and being beneficial to wound healing.

[0025] 2. The medical dressing of the present invention also adds components such as jasminin and oligopeptide-1. The test results show that the combined use of jasminin and oligopeptide-1 can effectively inhibit the excessive proliferation of scar tissue and reduce the formation of scars.

[0026] 3. The preparation method of the medical dressing provided by the present invention has simple steps and easy operation. Description of the Drawings

[0027] Figure 1 is the morphological diagram of passage 4 umbilical cord mesenchymal stem cells. Detailed Embodiments

[0028] The following combines the detailed embodiments to further describe the present invention. It should be noted that on the premise of no conflict, any combination can be formed between the following described embodiments or technical features to form new embodiments. The specific conditions not specified in the embodiments are carried out according to the conventional conditions. The reagents or instruments used, unless otherwise specified, are all conventional products obtained through commercial channels.

[0029] The acquisition method of umbilical cord mesenchymal stem cell exosomes is as follows:

[0030] Wash 1 mm clean 3Umbilical cord tissue of a certain size was laid flat in a culture dish. The culture medium in the culture dish was DMEM / F12 medium containing 10% fetal bovine serum. The culture dish was placed in a 37°C, 5% CO 2 cell incubator. After culturing until the cell confluence reached 85%, the primary cultured umbilical cord mesenchymal stem cells were obtained after digestion; at a density of 2×10 4 cells / mL, the primary cultured umbilical cord mesenchymal stem cells were inoculated into the culture medium (consisting of DMEM / F12 basal medium and the following components added to the medium: 8% FBS, 30 ng / mL IL-21, 2 ng / mL EGF). When the cell confluence reached 90%, after trypsin digestion, it was then placed in a 37°C, 5% CO 2 cell incubator for passage. The passage ratio was 1:3, and continuous passage was carried out 4 times to obtain P4-generation umbilical cord mesenchymal stem cells. The morphological diagram of the P4-generation umbilical cord mesenchymal stem cells is as shown in Figure 1 Figure.

[0031] At a density of 2×10 4 cells / mL, the P4-generation umbilical cord mesenchymal stem cells were inoculated into the culture medium (consisting of DMEM / F12 basal medium and the following components added to the medium: 8% FBS, 30 ng / mL IL-21, 2 ng / mL EGF), and cultured in a 37°C, 5% CO 2 cell incubator for 3 days. The cell culture supernatant was collected and the umbilical cord mesenchymal stem cell exosomes were obtained after centrifugation and lyophilization.

[0032] 1. Example

[0033] Example 1

[0034] This example provides a medical dressing for promoting diabetic wound healing. By mass percentage, it is composed of the following raw materials: 0.001% umbilical cord mesenchymal stem cell exosomes, 0.003% oligopeptide-1, 0.007% jasminin, 0.05% modified CaSi 2 nano-sheets, 4% hydroxypropyl chitosan, 0.2% xanthan gum, 3% glycerol, and the balance is water.

[0035] The preparation process of the above-mentioned modified CaSi 2 nano-sheets is as follows:

[0036] According to the dosage ratio of CaSi 2 powder and N-methyl-2-pyrrolidone of 1 g:50 mL, CaSi with a particle size of 3-5 μm 2The powder was dispersed in N-methyl-2-pyrrolidone and subjected to probe sonication for 11 h under ice bath conditions (sonication conditions: 900 W, 25% duty cycle). Then, the mixture was centrifuged at 1000 rpm for 5 min, and the suspension was further centrifuged at 15000 rpm for 20 min. The precipitate was collected, washed three times with ethanol, and freeze-dried to obtain CaSi 2 nanosheets.

[0037] According to the dosage ratio of CaSi 2 nanosheets to phytic acid solution of 1 g: 190 mL, the CaSi 2 nanosheets were added to a phytic acid solution with a concentration of 0.45 mol / L and reacted at 40 °C for 1 h. After the reaction was completed, the solid product was obtained by filtration and dried at room temperature.

[0038] The preparation method of the above-mentioned medical dressing for promoting diabetic wound healing is as follows:

[0039] (1) According to the mass percentage ratio, hydroxypropyl chitosan and xanthan gum were added to water, stirred until completely dissolved, and then glycerol was added and mixed evenly to obtain a gel matrix;

[0040] (2) According to the mass percentage ratio, oligopeptide-1, jasminin, umbilical cord mesenchymal stem cell exosomes and modified CaSi 2 nanosheets were added to the gel matrix in step (1) and mixed evenly.

[0041] Example 2

[0042] This example provides a medical dressing for promoting diabetic wound healing, which is composed of the following raw materials by mass percentage: umbilical cord mesenchymal stem cell exosomes 0.012%, oligopeptide-1 0.005%, jasminin 0.01%, modified CaSi 2 nanosheets 0.07%, hydroxypropyl chitosan 6%, xanthan gum 0.5%, glycerol 5%, and the balance is water.

[0043] The preparation process of the above-mentioned modified CaSi 2 nanosheets is as follows:

[0044] According to the dosage ratio of CaSi 2 powder to N-methyl-2-pyrrolidone of 1 g: 55 mL, CaSi 2 powder with a particle size of 3-5 μm was dispersed in N-methyl-2-pyrrolidone and subjected to probe sonication for 12 h under ice bath conditions (sonication conditions: 900 W, 25% duty cycle). Then, the mixture was centrifuged at 1000 rpm for 5 min, and the suspension was further centrifuged at 15000 rpm for 20 min. The precipitate was collected, washed three times with ethanol, and freeze-dried to obtain CaSi 2 nanosheets.

[0045] According to CaSi 2 For the dosage ratio of nanosheets to phytic acid solution of 1 g: 200 mL, add CaSi 2 nanosheets to a phytic acid solution with a concentration of 0.5 mol / L, react at 45 °C for 0.5 h. After the reaction is completed, filter to obtain a solid product, and dry it at room temperature to obtain the product.

[0046] The preparation method of the above-mentioned medical dressing for promoting diabetic wound healing is as follows:

[0047] (1) According to the mass percentage ratio, add hydroxypropyl chitosan and xanthan gum to water, stir until completely dissolved, and then add glycerol, and mix evenly to obtain a gel matrix;

[0048] (2) According to the mass percentage ratio, add oligopeptide-1, jasminin, umbilical cord mesenchymal stem cell exosomes and modified CaSi 2 nanosheets to the gel matrix in step (1) and mix evenly.

[0049] Example 3

[0050] This example provides a medical dressing for promoting diabetic wound healing, which is composed of the following raw materials by mass percentage: umbilical cord mesenchymal stem cell exosomes 0.008%, oligopeptide-1 0.002%, jasminin 0.004%, modified CaSi 2 nanosheets 0.03%, hydroxypropyl chitosan 2%, xanthan gum 0.1%, glycerol 0.5%, and the balance is water.

[0051] The above-mentioned modified CaSi 2 The preparation process of nanosheets is as follows:

[0052] According to the dosage ratio of CaSi 2 powder to N-methyl-2-pyrrolidone of 1 g: 45 mL, disperse CaSi 2 powder with a particle size of 3-5 μm in N-methyl-2-pyrrolidone, perform probe sonication for 10 h under ice bath conditions (sonication conditions: 900 W, 25% duty cycle), then centrifuge the mixture at 1000 rpm for 5 min, take the suspension and further centrifuge it at 15000 rpm for 20 min, and wash the collected precipitate with ethanol 3 times, and freeze-dry to obtain CaSi 2 nanosheets.

[0053] According to the dosage ratio of CaSi 2 nanosheets to phytic acid solution of 1 g: 180 mL, add CaSi 2 nanosheets to a phytic acid solution with a concentration of 0.4 mol / L, react at 35 °C for 1.5 h. After the reaction is completed, filter to obtain a solid product, and dry it at room temperature to obtain the product.

[0054] The preparation method of the above-mentioned medical dressing for promoting diabetic wound healing is as follows:

[0055] (1) According to the mass percentage ratio, add hydroxypropyl chitosan and xanthan gum to water. After stirring until completely dissolved, add glycerol and mix evenly to obtain a gel matrix;

[0056] (2) According to the mass percentage ratio, add oligopeptide-1, jasminin, umbilical cord mesenchymal stem cell exosomes and modified CaSi 2 nanosheets to the gel matrix in step (1) and mix evenly.

[0057] 2. Comparative examples

[0058] Comparative example 1

[0059] The difference between comparative example 1 and example 1 is that: the modified CaSi 2 nanosheets are replaced with CaSi 2 nanosheets, and the rest is the same as example 1.

[0060] Comparative example 2

[0061] The difference between comparative example 2 and example 1 is that: the modified CaSi 2 nanosheets are omitted, and the rest is the same as example 1.

[0062] Comparative example 3

[0063] The difference between comparative example 3 and example 1 is that: oligopeptide-1 is omitted, and the content of jasminin is increased to 0.01%, and the rest is the same as example 1.

[0064] Comparative example 4

[0065] The difference between comparative example 4 and example 1 is that: jasminin is omitted, and the content of oligopeptide-1 is increased to 0.01%, and the rest is the same as example 1.

[0066] 3. Test examples

[0067] (1) Test subjects

[0068] A total of 70 male BALB / c mice at 6 weeks of age were acclimated for 2 weeks before dosing.

[0069] (2) Establish a diabetic model

[0070] After all mice were fasted for 12 h, they were intraperitoneally injected with 50 mg / kg streptozotocin (STZ) for 5 consecutive days. After the administration was completed, tail vein blood was collected every 5 days, and the blood glucose level was measured with a blood glucose meter. Three weeks later, when the fasting glucose concentration of the mice was higher than 300 mg / L, the mice were considered to have diabetes.

[0071] (3)Test procedure

[0072] All diabetic model mice were randomly divided into the groups of Examples 1-3 and Comparative Examples 1-4, with 10 mice in each group. All mice were fixed, and after removing the hair on the back of the mice, they were disinfected with 75% alcohol. Then, a 6 mg / mL sodium pentobarbital solution was intraperitoneally injected to anesthetize the mice, and a circular full-thickness skin wound with a diameter of 8 mm was formed on the back of the anesthetized mice. The wounds were treated with the medical dressings obtained in Examples 1-3 and Comparative Examples 1-4, respectively, and the dressings were changed every 2 days.

[0073] (4)Detection indexes

[0074] Wound healing: The wounds of the mice in the groups of Examples 1-3 and Comparative Examples 1-2 were photographed on the 0th, 4th, 8th, and 16th days after treatment, and the wound areas were measured and analyzed using ImageJ software. The results are shown in Table 1.

[0075] Scar residual width: After wound healing, the width of the widest part of the scar residue of the mice in the groups of Examples 1-3 and Comparative Examples 3-4 was calculated. The results are shown in Table 2.

[0076] Table 1: Residual wound area after using the medical dressings of the groups of Examples 1-3 and Comparative Examples 1-2

[0077]

[0078] Table 2: Scar width after using the medical dressings of the groups of Examples 1-3 and Comparative Examples 1-2

[0079]

[0080] As can be seen from Table 1, the medical dressings obtained in Examples 1-3 of the present invention can promote wound healing. Compared with Examples 1-3, in Comparative Example 1, the modified CaSi 2 nanosheets were replaced with CaSi 2 nanosheets, and in Comparative Example 2, the modified CaSi 2 nanosheets were omitted. The medical dressings obtained in the two groups had poor promoting effects on wound healing. The above results show that the modified CaSi 2 nanosheets obtained in the present invention can promote wound healing. Specifically, in the process of modifying the CaSi 2 nanosheets, the chelating property of phytic acid was utilized, so that the calcium ions in the CaSi 2 nanosheets were dissolved out, while the complete silicon-based skeleton was retained, making the modified CaSi 2 nanosheets able to improve the stability and pro-angiogenic activity of umbilical cord mesenchymal stem cell exosomes, thereby improving the impaired angiogenesis in diabetic wounds and being beneficial to wound healing.

[0081] As can be seen from Table 2, the medical dressings obtained in Examples 1-3 of the present invention are beneficial to the repair of scars after wound healing. Compared with Examples 1-3, in Comparative Example 3, oligopeptide-1 was omitted and the content of jasminin was increased; in Comparative Example 4, jasminin was omitted and the content of oligopeptide-1 was increased. The medical dressings obtained in the two groups showed poor repair effects on scars after wound healing. The above results indicate that the combined use of jasminin and oligopeptide-1 can effectively inhibit the excessive proliferation of scar tissue and reduce the formation of scars.

[0082] The above embodiments are only the preferred embodiments of the present invention, and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention belong to the scope of protection required by the present invention.

Claims

1. A medical dressing for promoting healing of diabetic wounds, characterized in that: Calculated by mass percentage, it includes the following raw materials: Stem cell exosomes 0.008-0.012%, oligopeptide-1 0.002-0.005%, jasmine 0.004-0.01%, modified CaSi2 nanosheets 0.03-0.07%, hydroxypropyl chitosan 2-6%, xanthan gum 0.1-0.5%, glycerol 0.5-5%, and the balance is water; The preparation process of the modified CaSi2 nanosheets is as follows: adding the CaSi2 nanosheets to a phytic acid solution for reaction, and purifying after the reaction is completed to obtain the modified CaSi2 nanosheets.

2. The medical dressing for promoting diabetic wound healing according to claim 1, characterized in that: The dosage ratio of the CaSi2 nanosheets to the phytic acid solution is 1 g: (180-200) mL, and the concentration of the phytic acid solution is 0.4-0.5 mol / L.

3. The medical dressing for promoting diabetic wound healing according to claim 1, characterized in that: The reaction temperature is 35-45°C, and the reaction time is 0.5-1.5h.

4. The medical dressing for promoting diabetic wound healing according to claim 1, characterized in that: The preparation process of the CaSi2 nanosheets is as follows: dispersing CaSi2 powder into N-methyl-2-pyrrolidone, performing probe ultrasonic treatment and centrifugation under ice bath conditions, collecting the precipitate and washing and drying the precipitate.

5. The medical dressing for promoting diabetic wound healing according to claim 4, characterized in that: The dosage ratio of the CaSi2 powder and N-methyl-2-pyrrolidone is 1 g: (45-55) mL, and the time of the probe ultrasonic treatment is 10-12 h.

6. The medical dressing for promoting diabetic wound healing according to claim 1, characterized in that: The stem cell exosomes are umbilical cord mesenchymal stem cell exosomes.

7. The medical dressing for promoting diabetic wound healing according to claim 6, characterized in that: The method for obtaining the umbilical cord mesenchymal stem cell exosomes is: According to (0.5-3.5) × 10 4 The P3-P5 umbilical cord mesenchymal stem cells were inoculated into the culture medium at a density of cells / mL, and the supernatant was obtained. The supernatant was subjected to ultracentrifugation to obtain the precipitate, which was then freeze-dried.

8. The medical dressing for promoting healing of diabetic wounds according to claim 7, characterized in that: The culture medium consists of DMEM / F12 basal medium and the following components added to the culture medium: 5-10% FBS, 25-40 ng / mL IL-21, and 1-3 ng / mL EGF.

9. The method for preparing the medical dressing for promoting diabetic wound healing according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Add hydroxypropyl chitosan and xanthan gum to water according to the mass percentage ratio, stir until completely dissolved, add glycerol, and mix well to obtain a gel matrix; (2) Add oligopeptide-1, jasmine, stem cell exosomes and modified CaSi2 nanosheets into the gel matrix of step (1) according to the mass percentage ratio and mix evenly.

Images