An antibacterial dressing for skin repair and a method of preparing the same

Abstract

The application discloses antibacterial dressing for skin repair and a preparation method thereof, and relates to the field of medical dressings.The antibacterial dressing for skin repair comprises the following raw materials in parts by weight: carboxymethyl chitosan 4-8 parts, collagen 2-5 parts, glycerol 5-10 parts, a skeleton material 10-20 parts, an antibacterial agent 1-2 parts, a moisturizing agent 1-3 parts, and purified water 70 parts.The antibacterial dressing for skin repair prepared by the application has good moisturizing performance and antibacterial performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical dressings, in particular to an antibacterial dressing for skin repair and a preparation method thereof. BACKGROUND

[0002] Skin is the largest barrier organ of the human body, and its damage (such as surgical incision, burn, etc.) is easy to cause bacterial infection, leading to aggravated inflammation, delayed healing and even complications. Traditional dressings (such as gauze, absorbent cotton) can only play a physical covering role, and have defects such as poor moisturizing property, easy adhesion to the wound, and inability to actively resist bacteria. Traditional antibacterial dressings mostly rely on a single antibacterial component (such as silver ions, antibiotics), and long-term use can easily induce bacterial resistance, and silver ions may accumulate in the wound to cause cytotoxicity, and systemic absorption of antibiotics can also cause side effects such as imbalance of intestinal flora. Most moisturizing dressings (such as hyaluronic acid gel, glycerol dressing) lack active antibacterial ability, and antibacterial dressings often ignore the construction of the moist microenvironment of the wound, making it difficult to meet the repair needs of complex wounds.

[0003] Chinese patent with publication number CN106512064A discloses a skin wound dressing with antibacterial property and a preparation method thereof. The skin wound dressing provided by the application is a sponge-like porous membrane structure, and a sodium alginate fiber membrane is prepared by a freeze-drying method with sodium alginate as a matrix. The bio-antibacterial peptide Cys-KR12 is fixed on the fiber membrane by surface modification to obtain the prepared product. The skin wound dressing prepared by the application has a simple preparation method, rich material sources, overcomes the deficiencies of existing antibacterial dressings such as long-term use causing drug resistance and single function, has low immunogenicity, good biocompatibility, antibacterial property and repair induction function, can promote the healing of the wound and the growth of epithelial cells, and is beneficial to re-epithelialization of the wound, but the moisturizing property is still insufficient. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide an antibacterial dressing for skin repair and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the present application realizes the following technical solutions:

[0006] An antibacterial dressing for skin repair, comprising the following raw materials by weight:

[0007] Carboxymethyl chitosan 4-8 parts, collagen 2-5 parts, glycerol 5-10 parts, skeleton material 10-20 parts, antibacterial agent 1-2 parts, humectant 1-3 parts, and purified water 70 parts;

[0008] The humectant is prepared by the following method:

[0009] S1: butanedioic acid dihydrazide is reacted with p-hydroxymethyl benzaldehyde to obtain intermediate 1;

[0010] S2: intermediate 1 is reacted with glycine to obtain intermediate 2;

[0011] S3: intermediate 2 is reacted with hyaluronic acid to obtain the moisturizer.

[0012] In step S1, the molar ratio of the succinic dihydrazide to the p-hydroxymethyl benzaldehyde is 1:(2.1-2.3).

[0013] In step S2, the molar ratio of the intermediate 1 to the glycine is 1:(2.1-2.3).

[0014] In step S3, the mass ratio of the intermediate 2 to the hyaluronic acid is (0.61-0.63):1.

[0015] The antibacterial agent is prepared by the following method:

[0016] N1: 2-(hydroxymethyl)quinolin-4(1H)-one is reacted with 3-[(2-aminoethyl)disulfanyl]propionic acid to obtain intermediate A;

[0017] N2: intermediate A is reacted with caffeic acid to obtain the antibacterial agent.

[0018] In step N1, the molar ratio of the 2-(hydroxymethyl)quinolin-4(1H)-one to the 3-[(2-aminoethyl)disulfanyl]propionic acid is 1:(1.1-1.3).

[0019] In step N2, the molar ratio of the intermediate A to the caffeic acid is 1:(1.05-1.2).

[0020] The collagen is a recombinant human collagen.

[0021] The skeleton material is polyvinyl alcohol.

[0022] A preparation method of the antibacterial dressing for skin repair, comprising the following steps:

[0023] (1) the following are weighed by weight parts: carboxymethyl chitosan 4-8 parts, collagen 2-5 parts, glycerol 5-10 parts, skeleton material 10-20 parts, antibacterial agent 1-2 parts, moisturizer 1-3 parts, and purified water 70 parts;

[0024] (2) the skeleton material is mixed with the purified water and heated, stirred and dissolved, and then cooled; the carboxymethyl chitosan, collagen, glycerol, moisturizer, and antibacterial agent are added and stirred and uniformly mixed; vacuum degassing is performed; freeze-drying is performed; and irradiation sterilization is performed, to obtain the antibacterial dressing for skin repair.

[0025] Due to the above technical solutions, the beneficial effects of the present application include:

[0026] The antibacterial dressing for skin repair prepared by this invention has excellent moisturizing and antibacterial properties. This is mainly because the added moisturizer connects the hyaluronic acid backbone through dynamic acylhydrazone bonds, which can maintain the high-efficiency moisturizing ability of hyaluronic acid and achieve pH-responsive dynamic moisturizing, adapting to the wound microenvironment and realizing the "moisturizing-repair" response of the antibacterial dressing for skin repair. The added antibacterial agent is connected to caffeic acid through disulfide bonds on quinoline ketone. The phenolic hydroxyl group of caffeic acid can destroy bacterial cell membranes, inhibit biofilm formation, and improve antibacterial properties. The quinoline ketone structure can exert antibacterial effects by inhibiting bacterial DNA gyrase and interfering with metabolism, and can cover the main pathogenic bacteria of wound infection. Attached Figure Description

[0027] Figure 1 The 1H NMR spectrum of intermediate 1 prepared in Example 1.

[0028] Figure 2 The 1H NMR spectrum of intermediate 2 prepared in Example 1.

[0029] Figure 3 The image shows the 1H NMR spectrum of intermediate A prepared in Example 4.

[0030] Figure 4 The image shows the 1H NMR spectrum of the antibacterial agent prepared in Example 4. Detailed Implementation

[0031] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0032] Example 1: Preparation of humectant:

[0033] S1: Add 0.1 mol of succinic dihydrazide to 80 ml of glacial acetic acid and stir until homogeneous. Add 0.21 mol of p-hydroxymethylbenzaldehyde to 100 ml of isopropanol and stir until homogeneous. Mix the two solutions and react at 60 °C for 2 h. Cool to 0 °C and stir for 8 h to precipitate. Filter and wash successively with anhydrous ethanol (3 × 100 ml) and water (3 × 100 ml). Dry under vacuum at 50 °C for 12 h to obtain intermediate 1. The reaction equation is shown below:

[0034]

[0035] Its proton nuclear magnetic resonance spectrum is as follows Figure 1 The 1H NMR data are shown below:

[0036] 1 H NMR (400 MHz, Chloroform- d) δ 10.81 (s, 2H), 7.98 (t, J = 1.0 Hz,2H), 7.60-7.52 (m, 4H), 7.25-7.17 (m, 4H), 5.55 (ddt, J = 12.4, 5.0, 1.0 Hz,2H), 5.23 (ddt, J = 12.4, 5.0, 1.0 Hz, 2H), 3.72 (t, J = 5.0 Hz, 2H), 2.81(s, 4H);

[0037] S2: Under nitrogen protection, 0.21 mol glycine and 0.26 mol triethylamine were added into 300 ml anhydrous DMF, stirred and mixed uniformly, 120 ml anhydrous DMF solution containing 0.12 mol chloroformic acid-9-fluorenylmethyl ester was slowly added dropwise at 0°C (dropwise for 20 min), after stirring at 25°C for 12 h, 0.13 mol 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 0.06 mol 4-dimethylaminopyridine were added in 5 batches (each batch interval 5 min), stirred and activated for 45 min under ice bath, then 0.1 mol intermediate 1 was added, reacted at 25°C for 16 h, the reaction liquid was poured into 500 ml ice water (containing 25 ml 1M HCl), stirred for 30 min, neutralized triethylamine; extracted with ethyl acetate for 3 times (each time using 500 ml), after the organic phase was combined, washed with 500 ml saturated brine, added with 50 g anhydrous sodium sulfate and dried for 2 h, filtered, concentrated under reduced pressure at 50°C for 1 h to obtain a concentrated liquid, the concentrated liquid was added into a mixed solution of 300 ml DMF and piperidine (the mixed volume ratio of DMF and piperidine was 4:1), deprotected after stirring at 25°C for 35 min, then added into 500 ml 0.5M HCl solution at 0°C, stirred to precipitate, filtered, washed with 200 ml cold water, 100 ml 5wt% sodium bicarbonate solution and 200 ml cold water in sequence, vacuum dried at 40°C for 12 h to obtain intermediate 2; the reaction equation is shown as follows:

[0038]

[0039] The nuclear magnetic resonance hydrogen spectrum is shown in Figure 2 The nuclear magnetic hydrogen spectrum data are as follows:

[0040] 1 H NMR (500 MHz, DMSO- d6) δ 11.16 (s, 2H), 8.02 (t, J = 1.0 Hz, 2H), 7.67-7.60 (m, 4H), 7.42-7.35 (m, 4H), 5.14 (t, J = 1.0 Hz, 4H), 4.38-4.15 (m, 4H), 3.83 (s, 4H), 2.80 (s, 4H);

[0041] S3: Under nitrogen protection, 10 g of hyaluronic acid (number average molecular weight 5000 Da) was mixed with 50 ml of anhydrous DMF and 50 ml of purified water, 0.46 g of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 0.28 g of N-hydroxysuccinimide were mixed and then added to the hyaluronic acid solution in 5 batches (with an interval of 5 min), and the activation was stirred in an ice bath for 45 min; under nitrogen protection, 6.1 g of intermediate 2 was added to 50 ml of anhydrous DMF and stirred to mix, and the activated hyaluronic acid solution was slowly added dropwise, and after 1 h of dropwise addition, the reaction was carried out at 25°C for 9 h (during the reaction, 0.1 M HCl / NaOH solution was used to maintain the pH of the solution between 7.2-7.6), the mixture was loaded into a dialysis bag with a molecular weight cutoff of 8000 Da, and dialyzed with purified water for 72 h (every 6 hours, change 2000 ml of water), and freeze-dried at -50°C for 24 h to obtain the moisturizer; during the reaction, the amino group of intermediate 2 reacts with the carboxyl group of hyaluronic acid to form an amide.

[0042] Example 2 Preparation of moisturizer:

[0043] S1: 0.1 mol of succinic dihydrazide was added to 80 ml of glacial acetic acid and stirred to mix, 0.22 mol of p-hydroxymethyl benzaldehyde was added to 100 ml of isopropyl alcohol and stirred to mix, the two solutions were mixed, and the reaction was carried out at 65°C for 1.5 h, cooled to 0°C, and stirred for 8 h to precipitate, filtered, washed with anhydrous ethanol (3 x 100 ml) and water (3 x 100 ml) in sequence, and dried at 50°C under vacuum for 12 h to obtain intermediate 1;

[0044] S2: Under nitrogen protection, 0.22 mol glycine and 0.26 mol triethylamine were added into 300 ml anhydrous DMF, stirred and mixed, 120 ml anhydrous DMF solution containing 0.12 mol chloroformic acid-9-fluorenylmethyl ester was slowly added dropwise at 0°C (dropwise for 20 min), after stirring at 25°C for 12 h, a mixture of 0.13 mol 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 0.06 mol 4-dimethylaminopyridine was added in 5 batches (each batch interval 5 min), stirred and activated in ice bath for 45 min, then 0.1 mol intermediate 1 was added, reacted at 25°C for 15 h, the reaction liquid was poured into 500 ml ice water (containing 25 ml 1M HCl), stirred for 30 min, neutralized triethylamine; extracted with ethyl acetate for 3 times (500 ml each time), the combined organic phase was washed with 500 ml saturated brine, 50 g anhydrous sodium sulfate was added and dried for 2 h, filtered, concentrated under reduced pressure at 50°C for 1 h to obtain a concentrated liquid, the concentrated liquid was added into a mixed solution of 300 ml DMF and piperidine (the volume ratio of DMF to piperidine was 4:1), stirred at 25°C for 35 min for deprotection, then 500 ml 0.5M HCl solution at 0°C was added, stirred to precipitate, filtered, washed with 200 ml cold water, 100 ml 5wt% sodium bicarbonate solution and 200 ml cold water in sequence, vacuum dried at 40°C for 12 h to obtain intermediate 2;

[0045] S3: Under nitrogen protection, 10 g hyaluronic acid (number average molecular weight was 5000 Da) was mixed with 50 ml anhydrous DMF and 50 ml purified water, 0.46 g 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 0.28 g N-hydroxysuccinimide were mixed and added into the hyaluronic acid solution in 5 batches (each batch interval 5 min), stirred and activated in ice bath for 45 min; under nitrogen protection, 6.2 g intermediate 2 was added into 50 ml anhydrous DMF at room temperature, stirred and mixed, the activated hyaluronic acid solution was slowly added dropwise, after dropwise for 1 h, reacted at 25°C for 8 h (the pH of the solution was maintained at 7.2-7.6 by using 0.1M HCl / NaOH solution during the reaction), the mixture was loaded into a dialysis bag with a molecular weight cut-off of 8000 Da, dialyzed with purified water for 72 h (2000 ml of water was replaced every 6 hours), freeze-dried at -50°C for 24 h to obtain the moisturizer.

[0046] Example 3 Preparation of the moisturizer:

[0047] S1: 0.1 mol succinic dihydrazide was added into 80 ml glacial acetic acid, 0.23 mol p-hydroxymethyl benzaldehyde was added into 100 ml isopropyl alcohol, and stirred and mixed, the two solutions were mixed, and reacted at 70°C for 1 h, cooled to 0°C, and stirred for 8 h to precipitate a precipitate, which was filtered, washed with anhydrous ethanol (3 x 100 ml) and water (3 x 100 ml) in sequence, and dried at 50°C under vacuum for 12 h to obtain intermediate 1;

[0048] S2: 0.23 mol glycine and 0.26 mol triethylamine were added into 300 ml anhydrous DMF and stirred and mixed, 120 ml anhydrous DMF containing 0.12 mol chloroformic acid-9-fluorenylmethyl ester was slowly added dropwise (dropwise for 20 min) at 0°C, stirred at 25°C for 12 h, and then a mixture of 0.13 mol 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 0.06 mol 4-dimethylaminopyridine was added in 5 batches (each batch was separated by 5 min), stirred and activated in an ice bath for 45 min, then 0.1 mol intermediate 1 was added, reacted at 30°C for 14 h, the reaction liquid was poured into 500 ml ice water (containing 25 ml 1M HCl), stirred for 30 min, and neutralized triethylamine; extracted with ethyl acetate for 3 times (500 ml each time), washed with 500 ml saturated brine after the organic phases were combined, added with 50 g anhydrous sodium sulfate and dried for 2 h, filtered, concentrated at 50°C under reduced pressure for 1 h to obtain a concentrated solution, the concentrated solution was added into a mixed solution of 300 ml DMF and piperidine (the volume ratio of DMF to piperidine was 4:1), stirred at 25°C for 35 min to deprotect, then added into 500 ml 0.5M HCl solution at 0°C, stirred to precipitate a precipitate, which was filtered, washed with 200 ml cold water, 100 ml 5 wt% sodium bicarbonate solution, and 200 ml cold water in sequence, and dried at 40°C under vacuum for 12 h to obtain intermediate 2;

[0049] S3: 10 g hyaluronic acid (number average molecular weight was 5000 Da) was mixed with 50 ml anhydrous DMF and 50 ml purified water, a mixture of 0.46 g 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 0.28 g N-hydroxysuccinimide was prepared, and then added into the hyaluronic acid solution in 5 batches (each batch was separated by 5 min), and stirred and activated in an ice bath for 45 min; under nitrogen protection, 6.3 g intermediate 2 was added into 50 ml anhydrous DMF and stirred and mixed, and then the activated hyaluronic acid solution was slowly added dropwise, after dropwise addition for 1 h, reacted at 30°C for 7 h (0.1M HCl / NaOH solution was used to maintain the pH of the solution between 7.2-7.6 during the reaction), the mixture was loaded into a dialysis bag with a molecular weight cut-off of 8000 Da, dialyzed with purified water for 72 h (2000 ml of water was changed every 6 hours), and freeze-dried at -50°C for 24 h to obtain the moisturizer.

[0050] Example 4 Preparation of antibacterial agent:

[0051] N1: 0.11 mol of 3-[(2-aminoethyl)disulfanyl]propionic acid and 0.16 mol of triethylamine were added to 300 ml of anhydrous DMF, stirred and mixed well, 120 ml of anhydrous DMF solution containing 0.12 mol of chloroformic acid-9-fluorenylmethyl ester was slowly added dropwise at 0°C (dropwise for 20 min), stirred at 25°C for 12 h, then 0.13 mol of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.06 mol of 4-dimethylaminopyridine were added in 5 batches (5 min interval between each batch), stirred and activated in an ice bath for 45 min, then 0.1 mol of 2-(hydroxymethyl)quinolin-4(1H)-one was added, reacted at 25°C for 16 h, the reaction solution was poured into 500 ml of ice water (containing 25 ml of 1M HCl), stirred for 30 min, neutralized triethylamine; extracted with ethyl acetate for 3 times (500 ml each time), the combined organic phase was washed with 500 ml of saturated brine, 50 g of anhydrous sodium sulfate was added and dried for 2 h, filtered, and concentrated under reduced pressure at 50°C for 1 h to obtain a concentrated solution, the concentrated solution was added to a mixed solution of 250 ml of DMF and piperidine (the volume ratio of DMF to piperidine was 4:1), deprotected by stirring at 25°C for 35 min, then added to 500 ml of 0.5M HCl solution at 0°C, stirred to precipitate, filtered, washed with 200 ml of cold water, 100 ml of 5wt% sodium bicarbonate solution, and 200 ml of cold water in sequence, and vacuum dried at 40°C for 12 h to obtain intermediate A; the reaction equation is shown as follows:

[0052]

[0053] The proton nuclear magnetic resonance spectrum thereof is shown in Figure 3 The proton nuclear magnetic resonance data are as follows:

[0054] 1 H NMR (300 MHz, DMSO- d 6) δ 10.17 (s, 1H), 7.97-7.88 (m, 1H), 7.42-7.27 (m, 2H), 7.32-7.22 (m, 1H), 6.46 (s, 1H), 4.83 (s, 2H), 3.16-2.98 (m,4H), 2.78 (s, 2H), 2.64 (s, 2H), 1.83 (d, J = 0.6 Hz, 1H), 1.73 (d, J = 0.6Hz, 1H);

[0055] N2: Under nitrogen protection, 0.105 mol caffeic acid was mixed with 300 ml anhydrous DMF, 0.13 mol 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and 0.13 mol N-hydroxysuccinimide were mixed and then added into the caffeic acid solution in 5 batches (with 5 min interval), and stirred under ice bath for 45 min of activation; under nitrogen protection, 0.1 mol intermediate A was added into 150 ml anhydrous DMF under stirring and mixing, and the activated caffeic acid DMF solution was added dropwise slowly, dropwise for 1 h, and reacted at 25°C for 9 h (during the reaction, 0.1 M HCl / NaOH solution was used to maintain the pH of the solution between 7.2-7.6), the mixture was poured into 500 ml ice water for precipitation, filtered, and dialyzed with purified water for 72 h (molecular weight cut-off 400 Da, water was changed every 6 hours, 2000 ml each time), and freeze-dried at -50°C for 24 h to obtain the antibacterial agent; the reaction equation is shown as follows:

[0056]

[0057] The nuclear magnetic resonance hydrogen spectrum is shown in Figure 4

[0058] 1 H NMR (500 MHz, DMSO- d 6) δ 10.17 (s, 1H), 8.02 (d, J = 0.7 Hz, 1H),7.92 (dd, J = 7.3, 2.3 Hz, 1H), 7.36 (td, J = 7.4, 2.2 Hz, 1H), 7.32-7.25 (m,3H), 7.22 (s, 1H), 7.04-6.96 (m, 2H), 6.79 (d, J = 7.5 Hz, 1H), 6.57 (s, 1H),6.46 (s, 1H), 6.16 (s, 1H), 4.83 (s, 2H), 3.42-3.27 (m, 2H), 3.13 (s, 2H),2.83 (d, J = 12.4 Hz, 2H), 2.64 (s, 2H)。

[0059] Example 5 Preparation of antibacterial agent:

[0060] ​N1 : Under nitrogen protection, 0.12 mol 3-[(2-aminoethyl)disulfanyl]propionic acid and 0.16 mol triethylamine were added into 300 ml anhydrous DMF, stirred and mixed, 120 ml anhydrous DMF solution containing 0.12 mol chloroformic acid-9-fluorenylmethyl ester was slowly added dropwise at 0°C (dropwise for 20 min), stirred at 25°C for 12 h, 0.13 mol 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.06 mol 4-dimethylaminopyridine were added in 5 batches (each batch interval 5 min), stirred and activated in ice bath for 45 min, then 0.1 mol 2-(hydroxymethyl)quinolin-4(1H)-one was added, reacted at 25°C for 15 h, the reaction liquid was poured into 500 ml ice water (containing 25 ml 1M HCl), stirred for 30 min, neutralized triethylamine; extracted with ethyl acetate for 3 times (each time using 500 ml), the combined organic phase was washed with 500 ml saturated brine, 50 g anhydrous sodium sulfate was added and dried for 2 h, filtered, concentrated under reduced pressure at 50°C for 1 h to obtain a concentrated liquid, the concentrated liquid was added into a mixed solution of 250 ml DMF and piperidine (the mixed volume ratio of DMF and piperidine was 4:1), stirred at 25°C for 35 min for deprotection, then 500 ml 0.5M HCl solution at 0°C was added, the precipitate was stirred and separated, filtered, washed with 200 ml cold water, 100 ml 5wt% sodium bicarbonate solution and 200 ml cold water in sequence, vacuum dried at 40°C for 12 h to obtain intermediate A;

[0061] N2: Under nitrogen protection, 0.11 mol caffeic acid was mixed with 300 ml anhydrous DMF, 0.13 mol 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.13 mol N-hydroxysuccinimide were mixed, then added into the caffeic acid DMF solution in 5 batches (each batch interval 5 min), stirred and activated in ice bath for 45 min; under nitrogen protection, 0.1 mol intermediate A was added into 150 ml anhydrous DMF at room temperature, stirred and mixed, the activated caffeic acid solution was slowly added dropwise, dropwise for 1 h, reacted at 25°C for 8 h (the solution pH was maintained at 7.2-7.6 by using 0.1M HCl / NaOH solution during the reaction), the mixture was poured into 500 ml ice water to precipitate, filtered, dialyzed with purified water for 72 h (cut-off molecular weight 400 Da, water was changed every 6 hours, each time 2000 ml), freeze-dried at -50°C for 24 h to obtain the antibacterial agent.

[0062] Example 6 Preparation of the antibacterial agent:

[0063] N1 : Under nitrogen protection, 0.13 mol 3-[(2-aminoethyl)disulfanyl]propionic acid and 0.16 mol triethylamine were added into 300 ml anhydrous DMF, stirred and mixed, 120 ml anhydrous DMF solution containing 0.12 mol chloroformic acid-9-fluorenylmethyl ester was slowly added dropwise at 0°C (dropwise for 20 min), stirred at 25°C for 12 h, 0.13 mol 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.06 mol 4-dimethylaminopyridine were added in 5 batches (each batch interval 5 min), stirred and activated in ice bath for 45 min, then 0.1 mol 2-(hydroxymethyl)quinolin-4(1H)-one was added, reacted at 30°C for 14 h, the reaction liquid was poured into 500 ml ice water (containing 25 ml 1M HCl), stirred for 30 min, neutralized triethylamine; extracted with ethyl acetate for 3 times (each time using 500 ml), the organic phase was combined and washed with 500 ml saturated brine, 50 g anhydrous sodium sulfate was added and dried for 2 h, filtered, concentrated under reduced pressure at 50°C for 1 h to obtain a concentrated liquid, the concentrated liquid was added into a mixed solution of 250 ml DMF and piperidine (the mixed volume ratio of DMF and piperidine was 4:1), stirred at 25°C for 35 min for deprotection, then added into 500 ml 0.5M HCl solution at 0°C, stirred to precipitate, filtered, washed with 200 ml cold water, 100 ml 5wt% sodium bicarbonate solution and 200 ml cold water in sequence, vacuum dried at 40°C for 12 h to obtain intermediate A;

[0064] N2: Under nitrogen protection, 0.12 mol caffeic acid was mixed with 300 ml anhydrous DMF, 0.13 mol 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.13 mol N-hydroxysuccinimide were mixed and added into the caffeic acid DMF solution in 5 batches (each batch interval 5 min), stirred and activated in ice bath for 45 min; under nitrogen protection, 0.1 mol intermediate A was added into 150 ml anhydrous DMF at room temperature, stirred and mixed, the activated caffeic acid solution was slowly added dropwise, dropwise for 1 h, reacted at 30°C for 7 h (0.1M HCl / NaOH solution was used to maintain the solution pH at 7.2-7.6 during the reaction), the mixture was poured into 500 ml ice water to precipitate, filtered, dialyzed with purified water for 72 h (molecular weight cut-off 400 Da, water was changed every 6 hours, each time 2000 ml), freeze-dried at -50°C for 24 h to obtain the antibacterial agent.

[0065] Example 7 Preparation of skin repair antibacterial dressing:

[0066] (1) Weigh by weight: carboxymethyl chitosan 40 g, collagen (recombinant human collagen) 20 g, glycerol 50 g, scaffold material (polyvinyl alcohol) 100 g, antibacterial agent (prepared in Example 4) 10 g, moisturizing agent (prepared in Example 1) 10 g, purified water 700 g;

[0067] (2) The scaffold material is mixed with purified water and heated to 90°C, stirred at 500 rpm for 1 h, then cooled to 40°C. Carboxymethyl chitosan, collagen, glycerol, moisturizing agent and antibacterial agent are added, stirred at 500 rpm for 30 min, vacuum degassing (-0.08 MPa, 40°C) for 20 min, -50°C freeze drying for 24 h, and irradiation sterilization with γ-rays (irradiation dose 25 kGy) for 2 h to obtain the antibacterial dressing for skin repair.

[0068] Example 8 Preparation of antibacterial dressing for skin repair:

[0069] (1) Weigh by weight: carboxymethyl chitosan 40 g, collagen (recombinant human collagen) 20 g, glycerol 50 g, scaffold material (polyvinyl alcohol) 100 g, antibacterial agent (prepared in Example 4) 10 g, moisturizing agent (prepared in Example 1) 10 g, purified water 700 g;

[0070] (2) The scaffold material is mixed with purified water and heated to 90°C, stirred at 500 rpm for 1 h, then cooled to 40°C. Carboxymethyl chitosan, collagen, glycerol, moisturizing agent and antibacterial agent are added, stirred at 500 rpm for 30 min, vacuum degassing (-0.08 MPa, 40°C) for 20 min, -50°C freeze drying for 24 h, and irradiation sterilization with γ-rays (irradiation dose 25 kGy) for 2 h to obtain the antibacterial dressing for skin repair.

[0071] Example 9 Preparation of antibacterial dressing for skin repair:

[0072] (1) Weigh by weight: carboxymethyl chitosan 40 g, collagen (recombinant human collagen) 20 g, glycerol 50 g, scaffold material (polyvinyl alcohol) 100 g, antibacterial agent (prepared in Example 4) 10 g, moisturizing agent (prepared in Example 1) 10 g, purified water 700 g;

[0073] (2) The scaffold material is mixed with purified water and heated to 90°C, stirred at 500 rpm for 1 h, then cooled to 40°C. Carboxymethyl chitosan, collagen, glycerol, moisturizing agent and antibacterial agent are added, stirred at 500 rpm for 30 min, vacuum degassing (-0.08 MPa, 40°C) for 20 min, -50°C freeze drying for 24 h, and irradiation sterilization with γ-rays (irradiation dose 25 kGy) for 2 h to obtain the antibacterial dressing for skin repair.

[0074] Comparative Example 1

[0075] The raw material composition and the preparation method of the antibacterial dressing for skin repair are substantially the same as those of Example 8, except that the moisturizer (prepared in Example 2) in the composition is replaced with an equal weight of hyaluronic acid.

[0076] Comparative Example 2

[0077] The raw material composition and the preparation method of the antibacterial dressing for skin repair are substantially the same as those of Example 8, except that the moisturizer is replaced with an equal weight of a moisturizer prepared by the following method:

[0078] The preparation method of the moisturizer is substantially the same as that of Example 2, except that the succinic dihydrazide in step S1 is replaced with an equal molar amount of propionic hydrazide.

[0079] Comparative Example 3

[0080] The raw material composition and the preparation method of the antibacterial dressing for skin repair are substantially the same as those of Example 8, except that the moisturizer is replaced with an equal weight of a moisturizer prepared by the following method:

[0081] The preparation method of the moisturizer is substantially the same as that of Example 2, except that the hyaluronic acid in step S3 is replaced with 8 g of hyaluronic acid with a number average molecular weight of 4000 Da.

[0082] Comparative Example 4

[0083] The raw material composition and the preparation method of the antibacterial dressing for skin repair are substantially the same as those of Example 8, except that the antibacterial agent is replaced with an equal weight of an antibacterial agent prepared by the following method:

[0084] The preparation method of the antibacterial agent is substantially the same as that of Example 5, except that the 2-(hydroxymethyl)quinolin-4(1H)-one in step N1 is replaced with an equal molar amount of 2-(hydroxymethyl)pyridin-4(1H)-one (CAS No.: 933030-89-8).

[0085] Comparative Example 5

[0086] The raw material composition and the preparation method of the antibacterial dressing for skin repair are substantially the same as those of Example 8, except that the antibacterial agent is replaced with an equal weight of an antibacterial agent prepared by the following method:

[0087] The preparation method of the antibacterial agent is substantially the same as that of Example 5, except that the 3-[(2-aminoethyl)disulfanyl]propanoic acid in step N1 is replaced with an equal molar amount of 7-aminoheptanoic acid.

[0088] Comparative Example 6

[0089] The skin repair antibacterial dressing raw material composition and preparation method and example 8 are basically the same, the difference is that the antibacterial agent is replaced by equal weight of antibacterial agent prepared by the following method:

[0090] The preparation method of the antibacterial agent is basically the same as example 5, the difference is that the caffeic acid in step N2 is replaced by equal molar amount of salicylic acid.

[0091] The recombinant human collagen used in the examples and comparative examples of the present application is a recombinant type III humanized collagen produced by Zhuhai Jibai Kang Biological Technology Co., Ltd. The carboxymethyl chitosan has a carboxyl degree of 80% and a number average molecular weight of 9000 Da. The CAS number of 2-(hydroxymethyl) quinolin-4(1H)-one is 1088522-80-8. The polyvinyl alcohol is type 1788 and is produced by Shanghai Guchen Biological Technology Co., Ltd.

[0092] The skin repair antibacterial dressings prepared in examples 7-9 and comparative examples 1-6 were tested for moisture retention performance and antibacterial performance, and the test results are shown in Table 1.

[0093] Moisture retention performance test: The antibacterial dressings prepared in examples 7-9 and comparative examples 1-6 were placed on human epidermal skin at room temperature for moisture retention performance test. The initial mass of the dressing was weighed and recorded as m0, then the dressing was soaked in deionized water for swelling, then placed in a desiccator pre-filled with silica gel at 20°C for natural drying for 1h, then the mass was weighed every 1h and recorded as m t , the water absorption μ of the dressing was calculated by the formula μ=(m t -m0) / m0×100%. When μ is lower than 100% and there is no obvious change (the difference between the two calculated values is less than 5%), it is considered that the water in the dressing has evaporated completely, and the moisture retention time is recorded, and each group is tested 3 times to take the average.

[0094] Antibacterial performance test: The antibacterial dressings prepared in examples 7-9 and comparative examples 1-6 were cut into uniform circular shapes (diameter 9mm), placed in a glass bottle containing PBS buffer (0.1M, pH=7.4), sterilized at 121°C for 15min, and then cooled under ventilation and sterilized under ultraviolet irradiation for 1h in a clean bench. The test strain is Staphylococcus aureus. Single colonies were picked from the test strain, diluted with physiological saline, and the absorbance was adjusted to about 0.100 by spectrophotometer, i.e. the bacterial concentration was 10 8 CFU / ml. About 100μl of bacterial solution was dropped on the LB solid medium, and the bacterial solution was evenly coated with a coating rod. The cut sample to be tested was pasted, sealed, and the culture dish was placed in a 37°C biochemical incubator for constant temperature culture. After 24h, the bacterial growth on the culture medium was observed and the inhibition zone size was recorded.

[0095] Table 1

[0096]

[0097] As can be seen from Table 1, the skin repair antibacterial dressings prepared in Examples 7-9 have excellent moisturizing performance and antibacterial performance.

[0098] The antibacterial dressings prepared in Comparative Examples 1, 2 and 3 have poorer moisturizing performance than the examples, mainly because the single hyaluronic acid used in Comparative Example 1 has limited moisturizing performance, and the moisturizing agent lacks dynamic acylhydrazone bonds, making it difficult to achieve pH-responsive dynamic moisturizing, resulting in a decrease in moisturizing performance; the hyaluronic acid content of the moisturizing agent prepared in Comparative Example 2 is lower than that of the examples, resulting in a decrease in moisturizing performance; the hyaluronic acid used in Comparative Example 3 has a shorter molecular chain, the intermolecular hydrogen bond interaction is weakened, and the network structure is loose, resulting in a decrease in the water retention capacity of the moisturizing agent, resulting in a decrease in the moisturizing performance of the antibacterial dressing.

[0099] The antibacterial performance of the antibacterial dressings prepared in Comparative Examples 4, 5 and 6 is poorer than that of the examples, mainly because the antibacterial agent prepared in the examples connects quinolinone and caffeic acid molecules through a disulfide bond, the phenolic hydroxyl group of caffeic acid can destroy the bacterial cell membrane and inhibit the formation of biofilm, thereby improving the antibacterial performance; the quinolinone structure can play an antibacterial role by inhibiting bacterial DNA gyrase and interfering with metabolism. The antibacterial agent prepared in Comparative Example 4 using 2-(hydroxymethyl)pyridin-4(1H)-one lacks the bicyclic conjugated system of the benzene ring and the pyridine ring, resulting in a decrease in the binding ability to bacterial targets; the antibacterial agent prepared in Comparative Example 5 using 7-aminoheptanoic acid lacks a disulfide bond, making it difficult to achieve the distributed release of two active fragments; the antibacterial agent prepared in Comparative Example 6 using veratric acid has a reduced number of phenolic hydroxyl groups, and lacks the synergistic effect of two ortho-phenolic hydroxyl groups, resulting in a decrease in the ability to destroy the bacterial cell membrane, thereby resulting in a decrease in the antibacterial performance of the antibacterial dressing.

[0100] The above is only a preferred embodiment of the present application and is not intended to limit the present application; but for ordinary skilled persons in the art, some minor changes, modifications and equivalent changes made to the above disclosed technical content without departing from the scope of the technical solutions of the present application are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above embodiments made in accordance with the essential technology of the present application are still within the protection scope of the technical solutions of the present application.

Claims

1. An antibacterial dressing for skin repair, characterized in that, The ingredients include the following parts by weight: Carboxymethyl chitosan 4-8 parts, collagen 2-5 parts, glycerin 5-10 parts, scaffold material 10-20 parts, antibacterial agent 1-2 parts, moisturizer 1-3 parts, purified water 70 parts; The humectant is prepared by the following method: S1: Succinic dihydrazide reacts with p-hydroxymethylbenzaldehyde to give intermediate 1. S2: Intermediate 1 reacts with glycine to give intermediate 2. S3: Intermediate 2 reacts with hyaluronic acid with a number average molecular weight of 5000 Da to obtain a moisturizer.

2. The antibacterial dressing for skin repair according to claim 1, characterized in that, In step S1, the molar ratio of succinic dihydrazide and p-hydroxymethylbenzaldehyde is 1:(2.1-2.3).

3. The antibacterial dressing for skin repair according to claim 1, characterized in that, In step S2, the molar ratio of intermediate 1 to glycine is 1:(2.1-2.3).

4. The antibacterial dressing for skin repair according to claim 1, characterized in that, In step S3, the mass ratio of intermediate 2 to hyaluronic acid is (0.61-0.63):

1.

5. The antibacterial dressing for skin repair according to claim 1, characterized in that, The antibacterial agent is prepared by the following method: N1: 2-(hydroxymethyl)quinoline-4(1H)-one reacts with 3-[(2-aminoethyl)dithio]propionic acid to give intermediate A; N2: Intermediate A reacts with caffeic acid to obtain an antibacterial agent.

6. The antibacterial dressing for skin repair according to claim 5, characterized in that, In step N1, the molar ratio of 2-(hydroxymethyl)quinoline-4(1H)-one to 3-[(2-aminoethyl)dithio]propionic acid is 1:(1.1-1.3).

7. The antibacterial dressing for skin repair according to claim 5, characterized in that, In step N2, the molar ratio of intermediate A to caffeic acid is 1:(1.05-1.2).

8. The antibacterial dressing for skin repair according to claim 1, characterized in that, The collagen is recombinant human collagen.

9. The antibacterial dressing for skin repair according to claim 1, characterized in that, The skeleton material is polyvinyl alcohol.

10. A method for preparing an antibacterial dressing for skin repair according to any one of claims 1-9, characterized in that, Includes the following steps: (1) Weigh out the following by weight: 4-8 parts of carboxymethyl chitosan, 2-5 parts of collagen, 5-10 parts of glycerin, 10-20 parts of scaffold material, 1-2 parts of antibacterial agent, 1-3 parts of moisturizer, and 70 parts of purified water. (2) After mixing the skeleton material with purified water, heat it, stir to dissolve and then cool it. Add carboxymethyl chitosan, collagen, glycerin, moisturizer and antibacterial agent, stir and mix well, vacuum degas, freeze dry and then irradiate to sterilize, thus obtaining the antibacterial dressing for skin repair.

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