A medical transparent hydrogel dressing and preparation method thereof
By constructing a transparent hydrogel dressing with a dynamic three-dimensional network, the problems of transparency, mechanical properties and responsive drug release are solved, accurate monitoring and efficient repair of the wound surface are achieved, and the overall performance of the dressing is improved.
Patent Information
- Application Number
- CN202510431235.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2045-04-08
AI Technical Summary
Existing transparent hydrogel dressings have difficulties in transparency and mechanical properties, responsiveness and drug release efficiency, and multifunctional integration, making it difficult to meet the adaptability requirements of the dynamic pathological microenvironment of complex wounds.
A dynamic three-dimensional network was constructed by copolymerizing PCA/Fe³⁺ coordination complex with GA-DA to modify PDA nanoparticles and nitrogen-sulfur co-doped carbon quantum dots. Combined with UV curing technology, a medical transparent hydrogel dressing with high transparency, flexibility and responsive drug release was formed.
It achieves precise responsive drug release, visual observation and efficient repair to the wound environment, improves the mechanical strength of the material and the stability of the drug carrier, and enhances the comprehensive performance of wound management.
Smart Images
Figure CN119925687B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of medical dressings, and particularly relates to a medical transparent hydrogel dressing and a preparation method thereof. Background Art
[0002] As an important material for wound care, hydrogel dressings have been widely used in clinical practice. Their core advantages lie in the moist healing environment and local drug delivery capabilities brought by their high water content. However, existing products are mostly oriented towards single functions such as antibacterial, moisturizing and repair promotion, which makes it difficult to meet the adaptive regulation needs of complex wounds to the dynamic pathological microenvironment. In addition, most traditional gel dressings cannot achieve visual monitoring of the wound due to the poor light transmittance of the materials, so the timing of clinical dressing changes still depends on subjective judgment, increasing the risk of secondary injury. Based on this, transparent hydrogel dressings have gradually become a research hotspot. Their high light transmittance not only supports real-time observation of the wound, but also can integrate intelligent monitoring functions through optical means. However, this transparent hydrogel system brings about the difficult problem of balancing transparency and mechanical properties: high transparency often requires a uniform internal structure of the material, but low cross-linking density can easily lead to insufficient mechanical strength, making it difficult to resist exudate erosion or external friction; at the same time, a single response mechanism is difficult to cover the complex microenvironmental changes during wound healing, and the response accuracy and spatiotemporal controllability of drug release still need to be improved; in addition, although the low refractive index characteristics of the transparent matrix are beneficial to optical properties, they limit the stable loading of macromolecules or nanocarriers, resulting in low efficiency in the integration of multiple functions such as antibacterial, anti-inflammatory, and repair-promoting.
[0003] Therefore, there is an urgent need for a new type of transparent hydrogel dressing that can systematically solve the above technical difficulties through structural innovation and component synergy, and achieve responsive drug controlled release, visualization of the transparent matrix and efficient repair methods. Summary of the Invention
[0004] In response to the above situation, the present invention provides a medical transparent hydrogel dressing and a preparation method thereof. With "dynamic response-synergistic repair" as the core idea, the present invention addresses the problems of traditional dressings such as single function, insufficient environmental adaptability, and difficulty in balancing mechanical and biological properties. By synergistically constructing a dynamic three-dimensional network based on modified PDA nanoparticles copolymerized with PCA / Fe³⁺ coordination complex and GA-DA (gallic acid-dopamine) and nitrogen-sulfur co-doped carbon quantum dots, the dressing is given responsive drug release ability while taking into account high transparency, high air permeability and flexible adhesion, providing a new direction for the observation and repair of complex wounds.
[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:
[0006] The present invention provides a medical transparent hydrogel dressing. The hydrogel dressing comprises the following raw materials in parts by weight: 4-6 parts of citric acid, 2-3 parts of L-cysteine, 4-5.5 parts of chitosan, 0.8-1.5 parts of hyaluronic acid, 0.08-0.1 parts of MBA (methylenebisacrylamide), 0.8-1.2 parts of modified PDA (polydopamine), 0.04 parts of a photoinitiator, and 100 parts of a pH 6.5 PBS (phosphate) buffer solution.
[0007] Furthermore, the modified PDA includes the following raw materials in parts by weight: 0.4-0.48 parts of PCA (protocatechuic acid), 0.2-0.24 parts of FeCl3·6H2O, 0.4-0.48 parts of DA (dopamine), 0.2-0.24 parts of GA (gallic acid), 0.1 parts of trehalose, and 100 parts of pH 7.8 PBS buffer.
[0008] Furthermore, the photoinitiator is selected from any one of LAP (lithium phenyl-2,4,6-trimethylbenzoylphosphinate), curcumin and vitamin B2.
[0009] Furthermore, the chitosan has a deacetylation degree of 85%-90% and a molecular weight of 100-150 kDa.
[0010] Furthermore, the hyaluronic acid is composed of hyaluronic acid with a molecular weight of 100-1000 kDa and hyaluronic acid with a molecular weight of 10-100 kDa in a weight ratio of 3:1, and contains thiolated hyaluronic acid with a thiol group substitution degree of 5-8%.
[0011] Furthermore, the DA is in the form of hydrochloride.
[0012] The preparation method of the modified PDA specifically comprises the following steps:
[0013] S1: Weigh 0.4-0.48 parts of PCA and 0.2-0.24 parts of FeCl3·6H2O, dissolve them in 100 parts of pH 7.8 PBS buffer, and stir on ice for 10-30 minutes to obtain a coordination complex;
[0014] S2: Weigh 0.4-0.48 parts of DA and 0.2-0.24 parts of GA and add them to the coordination complex, stir at 4°C in the dark for 12 h to obtain GA-PDA polymer;
[0015] S3: The GA-PDA polymer was dialyzed using a 3 kDa dialysis membrane for 24 h, with the solution replaced every 8 h to obtain a dialysate. 0.1 parts of trehalose was weighed and dissolved in the dialysate, followed by freeze-drying to obtain modified PDA.
[0016] The present invention also provides a method for preparing a medical transparent hydrogel dressing, which specifically comprises the following steps:
[0017] Step 1: Weigh 4-6 parts of citric acid and 2-3 parts of L-cysteine and dissolve them in 100 mL of deionized water. Hydrothermally react at 160°C for 4 h to obtain a reaction solution. The reaction solution is dialyzed with a 1 kDa dialysis bag and then freeze-dried to obtain N,S-CDs (nitrogen-sulfur co-doped carbon quantum dots).
[0018] Step 2: Weigh 4-5.5 parts of chitosan, 0.8-1.5 parts of hyaluronic acid, and 0.08-0.1 parts of MBA and dissolve them in 100 parts of pH 6.5 PBS buffer to obtain a gel matrix;
[0019] Step 3: Weigh 0.8-1.2 parts of modified PDA and N,S-CDs and add them to the gel matrix, ultrasonically disperse them at 180 W for 10 minutes, then weigh 0.04 parts of photoinitiator and add them to dissolve them. After UV curing, incubate at 37°C for 2 hours to obtain a medical transparent hydrogel dressing.
[0020] The beneficial effects achieved by the present invention are as follows:
[0021] The medical transparent hydrogel dressing prepared by the present invention achieves comprehensive performance improvement that is difficult to achieve with a single material through the synergistic effect of multiple components: the composite system of modified PDA nanoparticles and N,S-CDs constitutes a dynamic response intelligent core: PCA / Fe 3+ The coordination network gives the material pH sensitivity, while the GA-DA copolymer structure provides enzyme response sites. The two form a dual drug release switch through the complementary dissociation mechanism of chemical bonds, so that the release of antibacterial and antioxidant ingredients can not only respond to changes in the acidity of the inflammatory microenvironment, but also be specifically activated by the overexpressed MMP-9 enzyme, significantly improving the environmental adaptation accuracy compared with a single response mechanism; the rich functional groups on the surface of N,S-CDs can not only stabilize the dispersion state of the nanocarriers through π-π stacking with PDA, but also avoid the transmittance loss caused by nanoparticle agglomeration while enhancing the photothermal conversion efficiency, and have a two-way gain of responsiveness and optical transparency.
[0022] At the matrix level, the antimicrobial barrier formed by chitosan's cationic action and the cell migration-promoting properties of hyaluronic acid are interconnected. This hydrogel not only serves as a gel matrix but also possesses antimicrobial and anti-inflammatory properties. The presence of the MBA cross-linked network not only limits excessive swelling of the polysaccharide chains but also dissipates external stress through dynamic hydrogen bonding, creating invisible micropores in the material that maintain normal cell respiration at the wound site and enhance oxygen permeability. This "rigid skeleton-flexible buffer" composite structure, coupled with the nano-reinforcement effects of modified PDA, ensures that the hydrogel maintains structural integrity in the presence of wound exudate, providing a stable carrier platform for long-term drug release. During the preparation process, UV light curing precisely controls the free radical polymerization rate to form a uniform cross-linked network within tens of seconds, avoiding the degradation of chitosan chains caused by traditional thermal initiation. The low-temperature incubation phase repairs micro-defects through molecular chain relaxation and recombination. Combined with the freeze-dried protection of the PDA nanoparticles by trehalose, the stability of the active ingredient is enhanced.
[0023] The medical transparent hydrogel dressing provided by the present invention has functions such as dynamic drug release, controllable breathing micropores and transparent visibility, providing a breakthrough material solution for complex wound management. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 The scanning electron microscope characterization results of the transparent hydrogel dressing prepared in Example 4 and the gel appearance renderings;
[0025] Figure 2 These are the results of the skin adhesion test of the transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2;
[0026] Figure 3 Results of light transmittance testing of the transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2;
[0027] Figure 4 The results of the investigation on the swelling properties of the transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 are shown;
[0028] Figure 5 The cumulative release rate results of the transparent hydrogel dressings prepared in Examples 1 and 5 and Comparative Examples 1-2 in pH 5.5 and pH 7.4 media;
[0029] Figure 6 The results of the cell compatibility study of the transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2;
[0030] Figure 7 These are the results of cell migration scratch experiments on the transparent hydrogel dressings prepared in Example 4 and Comparative Example 2. DETAILED DESCRIPTION
[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only and are not intended to limit the scope of this application.
[0033] In the following examples, unless otherwise specified, conventional methods are used; the materials used in the following examples, unless otherwise specified, are all new materials purchased from the market.
[0034] Example 1: This example provides a medical transparent hydrogel dressing, which comprises the following raw materials in parts by weight: 4 parts of citric acid, 2 parts of L-cysteine, 4 parts of chitosan, 1.5 parts of hyaluronic acid, 0.1 parts of MBA, 0.8 parts of modified PDA, 0.04 parts of LAP, and 100 parts of pH 6.5 PBS buffer. The molecular weight of chitosan is 100 kDa, the degree of deacetylation is 90%, and the degree of substitution of thiol groups in hyaluronic acid is 6%.
[0035] The modified PDA includes the following raw materials in parts by weight: 0.4 parts of PCA, 0.2 parts of FeCl3·6H2O, 0.4 parts of DA, 0.2 parts of GA, 0.1 parts of trehalose and 100 parts of pH 7.8 PBS buffer. The specific preparation method is as follows:
[0036] S1: Weigh 0.4 parts of PCA and 0.2 parts of FeCl3·6H2O, dissolve them in 100 parts of pH 7.8 PBS buffer, and stir on ice for 10 min. The solution remains stable and transparent without any change in color, and the particle size is detected to be 54.2 nm, thus obtaining a coordination complex.
[0037] S2: Weigh 0.4 parts of DA and 0.2 parts of GA and add them to the coordination complex, stir at 4°C in the dark for 12 h to obtain GA-PDA polymer;
[0038] S3: The GA-PDA polymer was dialyzed using a 3 kDa dialysis membrane for 24 h, with the solution replaced every 8 h to obtain a dialysate. 0.1 parts of trehalose was weighed and dissolved in the dialysate, followed by freeze-drying to obtain modified PDA.
[0039] This embodiment also provides a method for preparing a medical transparent hydrogel dressing, which specifically comprises the following steps:
[0040] Step 1: Weigh 4 parts of citric acid and 2 parts of L-cysteine and dissolve them in 100 mL of deionized water. Hydrothermally react at 160°C for 4 h to obtain a reaction solution. The reaction solution is dialyzed using a 1 kDa dialysis bag and then freeze-dried to obtain N,S-CDs.
[0041] Step 2: Weigh 4 parts of chitosan, 1.5 parts of hyaluronic acid, and 0.1 parts of MBA and dissolve them in 100 parts of pH 6.5 PBS buffer to obtain a gel matrix;
[0042] Step 3: Weigh 0.8 parts of modified PDA and N,S-CDs and add them to the gel matrix. Ultrasonic dispersion is performed at 180 W for 10 min. Then, 0.04 parts of LAP are weighed and dissolved. After UV curing at 405 nm, the mixture is incubated at 37°C for 2 h to obtain a medical transparent hydrogel dressing.
[0043] Example 2: This example provides a medical transparent hydrogel dressing, which comprises the following raw materials in parts by weight: 5 parts of citric acid, 2.5 parts of L-cysteine, 4.5 parts of chitosan, 0.8 parts of hyaluronic acid, 0.08 parts of MBA, 1.2 parts of modified PDA, 0.04 parts of curcumin and 100 parts of pH 6.5 PBS buffer solution. The molecular weight of chitosan is 120 kDa, the degree of deacetylation is 85%, and the degree of substitution of thiol groups in hyaluronic acid is 5%.
[0044] The modified PDA includes the following raw materials in parts by weight: 0.48 parts of PCA, 0.22 parts of FeCl3·6H2O, 0.48 parts of DA, 0.22 parts of GA, 0.1 parts of trehalose, and 100 parts of pH 7.8 PBS buffer. The specific preparation method is as follows:
[0045] S1: Weigh 0.48 parts of PCA and 0.22 parts of FeCl3·6H2O, dissolve them in 100 parts of pH 7.8 PBS buffer, and stir on ice for 20 min. The solution remains stable and transparent without any change in color, and the particle size is detected to be 45.5 nm, thus obtaining a coordination complex.
[0046] S2: Weigh 0.48 parts of DA and 0.22 parts of GA and add them to the coordination complex, stir at 4°C in the dark for 12 h to obtain GA-PDA polymer;
[0047] S3: The GA-PDA polymer was dialyzed using a 3 kDa dialysis membrane for 24 h, with the solution replaced every 8 h to obtain a dialysate. 0.1 parts of trehalose was weighed and dissolved in the dialysate, followed by freeze-drying to obtain modified PDA.
[0048] This embodiment also provides a method for preparing a medical transparent hydrogel dressing, which specifically comprises the following steps:
[0049] Step 1: Weigh 5 parts of citric acid and 2.5 parts of L-cysteine and dissolve them in 100 mL of deionized water. Hydrothermally react at 160°C for 4 h to obtain a reaction solution. The reaction solution is dialyzed using a 1 kDa dialysis bag and then freeze-dried to obtain N,S-CDs.
[0050] Step 2: Weigh 4.5 parts of chitosan, 0.8 parts of hyaluronic acid, and 0.08 parts of MBA and dissolve them in 100 parts of pH 6.5 PBS buffer to obtain a gel matrix;
[0051] Step 3: Weigh 1.2 parts of modified PDA and N,S-CDs and add them to the gel matrix. Ultrasonic dispersion is performed at 180 W for 10 min. Then, 0.04 parts of curcumin is weighed and dissolved in 1 mL of ethanol and slowly transferred to the gel matrix. After UV curing at 510 nm, the mixture is incubated at 37°C for 2 h to obtain a medical transparent hydrogel dressing.
[0052] Example 3: This example provides a medical transparent hydrogel dressing, which comprises the following raw materials in parts by weight: 6 parts of citric acid, 3 parts of L-cysteine, 5.5 parts of chitosan, 1 part of hyaluronic acid, 0.09 parts of MBA, 1 part of modified PDA, 0.04 parts of vitamin B2 and 100 parts of pH 6.5 PBS buffer, with 0.01 parts of triethanolamine additionally added as a co-initiator. The molecular weight of chitosan is 150 kDa, the degree of deacetylation is 95%, and the degree of substitution of thiol groups in hyaluronic acid is 8%.
[0053] The modified PDA includes the following raw materials in parts by weight: 0.44 parts of PCA, 0.24 parts of FeCl3·6H2O, 0.44 parts of DA, 0.24 parts of GA, 0.1 parts of trehalose, and 100 parts of pH 7.8 PBS buffer. The specific preparation method is as follows:
[0054] S1: Weigh 0.44 parts of PCA and 0.24 parts of FeCl3·6H2O, dissolve them in 100 parts of pH 7.8 PBS buffer, and stir on ice for 30 min. The solution remains stable and transparent without any change in color, and the particle size is detected to be 71.8 nm, thus obtaining a coordination complex.
[0055] S2: Weigh 0.44 parts of DA and 0.24 parts of GA and add them to the coordination complex, stir at 4°C in the dark for 12 h to obtain GA-PDA polymer;
[0056] S3: The GA-PDA polymer was dialyzed using a 3 kDa dialysis membrane for 24 h, with the solution replaced every 8 h to obtain a dialysate. 0.1 parts of trehalose was weighed and dissolved in the dialysate, followed by freeze-drying to obtain modified PDA.
[0057] This embodiment also provides a method for preparing a medical transparent hydrogel dressing, which specifically comprises the following steps:
[0058] Step 1: Weigh 6 parts of citric acid and 3 parts of L-cysteine and dissolve them in 100 mL of deionized water. Hydrothermally react at 160°C for 4 h to obtain a reaction solution. The reaction solution is dialyzed using a 1 kDa dialysis bag and then freeze-dried to obtain N,S-CDs.
[0059] Step 2: Weigh 5.5 parts of chitosan, 1 part of hyaluronic acid, and 0.09 parts of MBA and dissolve them in 100 parts of pH 6.5 PBS buffer to obtain a gel matrix;
[0060] Step 3: Weigh 1 part of modified PDA and N,S-CDs and add them to the gel matrix. Ultrasonic dispersion is performed at 180 W for 10 min. Then, 0.04 part of vitamin B2 and 0.01 part of triethanolamine are weighed and added to the gel matrix. After UV curing at 337 nm, the mixture is incubated at 37°C for 2 h to obtain a medical transparent hydrogel dressing.
[0061] Example 4: This example provides a medical transparent hydrogel dressing, which comprises the following raw materials in parts by weight: 5 parts of citric acid, 3 parts of L-cysteine, 5 parts of chitosan, 1 part of hyaluronic acid, 0.1 parts of MBA, 1 part of modified PDA, 0.04 parts of LAP and 100 parts of pH 6.5 PBS buffer solution, the molecular weight of chitosan is 150 kDa, the degree of deacetylation is 90%, and the degree of substitution of thiol groups in hyaluronic acid is 6%.
[0062] The modified PDA includes the following raw materials in parts by weight: 0.4 parts of PCA, 0.24 parts of FeCl3·6H2O, 0.45 parts of DA, 0.2 parts of GA, 0.1 parts of trehalose, and 100 parts of pH 7.8 PBS buffer. The specific preparation method is as follows:
[0063] S1: Weigh 0.4 parts of PCA and 0.24 parts of FeCl3·6H2O, dissolve them in 100 parts of pH 7.8 PBS buffer, and stir on ice for 20 min. The solution remains stable and transparent without any change in color, and the particle size is detected to be 36.4 nm, thus obtaining a coordination complex.
[0064] S2: Weigh 0.45 parts of DA and 0.2 parts of GA and add them to the coordination complex, stir at 4°C in the dark for 12 h to obtain GA-PDA polymer;
[0065] S3: The GA-PDA polymer was dialyzed using a 3 kDa dialysis membrane for 24 h, with the solution replaced every 8 h to obtain a dialysate. 0.1 parts of trehalose was weighed and dissolved in the dialysate, followed by freeze-drying to obtain modified PDA.
[0066] This embodiment also provides a method for preparing a medical transparent hydrogel dressing, which specifically comprises the following steps:
[0067] Step 1: Weigh 5 parts of citric acid and 3 parts of L-cysteine and dissolve them in 100 mL of deionized water. Hydrothermally react at 160°C for 4 h to obtain a reaction solution. The reaction solution is dialyzed using a 1 kDa dialysis bag and then freeze-dried to obtain N,S-CDs.
[0068] Step 2: Weigh 5 parts of chitosan, 1 part of hyaluronic acid, and 0.1 part of MBA and dissolve them in 100 parts of pH 6.5 PBS buffer to obtain a gel matrix;
[0069] Step 3: Weigh 1 part of modified PDA and N,S-CDs and add them to the gel matrix. Ultrasonic dispersion is performed at 180 W for 10 min. Then 0.04 part of LAP is weighed and added to dissolve. After UV curing at 405 nm, the mixture is incubated at 37°C for 2 h to obtain a medical transparent hydrogel dressing.
[0070] Example 5: This example provides a medical transparent hydrogel dressing, which comprises the following raw materials in parts by weight: 4 parts of citric acid, 2 parts of L-cysteine, 4 parts of chitosan, 0.8 parts of hyaluronic acid, 0.1 parts of MBA, 1 part of modified PDA, 0.04 parts of LAP and 100 parts of pH 6.5 PBS buffer solution, the molecular weight of chitosan is 140 kDa, the degree of deacetylation is 90%, and the degree of substitution of thiol groups in hyaluronic acid is 7%.
[0071] The modified PDA includes the following raw materials in parts by weight: 0.4 parts of PCA, 0.2 parts of FeCl3·6H2O, 0.48 parts of DA, 0.24 parts of GA, 0.1 parts of trehalose, and 100 parts of pH 7.8 PBS buffer. The specific preparation method is as follows:
[0072] S1: Weigh 0.4 parts of PCA and 0.2 parts of FeCl3·6H2O, dissolve them in 100 parts of pH 7.8 PBS buffer, and stir on ice for 20 min. The solution remains stable and transparent without any change in color, and the particle size is detected to be 53.9 nm, thus obtaining a coordination complex.
[0073] S2: Weigh 0.48 parts of DA and 0.24 parts of GA and add them to the coordination complex, stir at 4°C in the dark for 12 h to obtain GA-PDA polymer;
[0074] S3: The GA-PDA polymer was dialyzed using a 3 kDa dialysis membrane for 24 h, with the solution replaced every 8 h to obtain a dialysate. 0.1 parts of trehalose was weighed and dissolved in the dialysate, followed by freeze-drying to obtain modified PDA.
[0075] This embodiment also provides a method for preparing a medical transparent hydrogel dressing, which specifically comprises the following steps:
[0076] Step 1: Weigh 4 parts of citric acid and 2 parts of L-cysteine and dissolve them in 100 mL of deionized water. Hydrothermally react at 160°C for 4 h to obtain a reaction solution. The reaction solution is dialyzed using a 1 kDa dialysis bag and then freeze-dried to obtain N,S-CDs.
[0077] Step 2: Weigh 4 parts of chitosan, 0.8 parts of hyaluronic acid, and 0.1 parts of MBA and dissolve them in 100 parts of pH 6.5 PBS buffer to obtain a gel matrix;
[0078] Step 3: Weigh 1 part of modified PDA and N,S-CDs and add them to the gel matrix. Ultrasonic dispersion is performed at 180 W for 10 min. Then 0.04 part of LAP is weighed and added to dissolve. After UV curing at 405 nm, the mixture is incubated at 37°C for 2 h to obtain a medical transparent hydrogel dressing.
[0079] The difference between Comparative Example 1 and Example 4 is that no modified PDA is added, and the other parts are the same as Example 4.
[0080] The difference between Comparative Example 2 and Example 4 is that no citric acid and L-cysteine are added, that is, no N,S-CDs are added, and the rest is the same as Example 4.
[0081] Morphology inspection
[0082] The transparent hydrogel dressing prepared in Example 4 was dispersed on a silicon wafer, and after spraying with gold, the gel morphology was observed under a cryo-scanning electron microscope (SEM). The gel appearance and SEM results were shown in Figure 2. Figure 1 .
[0083] Skin adhesion test
[0084] 2.0 g of each of the transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 were shaped in a 25 mm × 25 mm mold, adhered to the simulated skin surface, and allowed to stand for 5 minutes to eliminate the preload stress. The adhesion of the hydrogel was tested at 10 mm / min, a preload force of 0.1 N, and 25.0°C. The adhesion strength σ = F max / bonding area, a shear load was applied in the vertical direction of the sample at a shear rate of 5 mm / min, and the shear strength was tested; the transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 were molded into a size of 25 mm×100 mm×2 mm, adhered to the simulated skin surface, and the sample peeling force (F) was tested at a peeling rate of 300 mm / min and a peeling angle of 180°. Each group was tested 5 times, and the results are shown in FIG. Figure 2 .
[0085] Light transmittance testing
[0086] The transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 were made into smooth sheets with a thickness of 2 mm. The transmittance (T%) and haze (H%) at 550 nm were measured using a UV-visible spectrophotometer. The test was repeated three times. The results are shown in Table 1. Figure 3 .
[0087] Swelling rate test
[0088] After freeze-drying the transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2, 0.50 g of the dried gel (W0) was taken out and soaked in PBS at 37°C for 24 h. The surface moisture was absorbed and weighed (W1). The swelling ratio was calculated as (W1-W0) / W0×100%. The results are shown in Table 1. Figure 4 .
[0089] Drug dissolution testing
[0090] Weigh 2.00 g each of the transparent hydrogel dressings prepared in Example 1 and Example 4 and Comparative Examples 1-2, apply them evenly on medical gauze, and place them in a dissolution tester to detect the dissolution of GA in pH 5.5 and pH 7.4 PBS media. The dissolution medium is 900 mL, the temperature is 37±0.5°C, and samples are taken at 5 min, 30 min, 1 h, and 2 h. The paddle speed is 50 rpm, and the GA cumulative release rate is detected by high performance liquid chromatography. The results are shown in Table 1. Figure 5 .
[0091] Cell biocompatibility testing
[0092] The transparent hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 were extracted at 37°C for 24 h, and the extracts were added to HSF human skin fibroblasts. The absorbance (OD) of the cells at 450 nm was measured using the CCK-8 method. The control group consisted of HSF cells without extracts, and the blank group consisted of blank culture dishes without cells inoculated. The cell survival rate (%) was (OD) = 0. 实验 -OD 空白 ) / (OD 对照 -OD 空白 ) × 100%, see the results Figure 6 .
[0093] Cell scratch assay
[0094] HUVEC human umbilical vein endothelial cells were seeded in a 12-well plate. After the cells attached to the wall, scratches were made on the cells. The transparent hydrogel dressings prepared in Example 4 and Comparative Example 2 were extracted at 37°C for 24 hours. The extracts were added to the scratched cell wells and incubated in an incubator for 12 hours. The growth of the scratched cells was observed under a microscope. The cell wells without extract were used as the control group. The results are shown in Figure 2. Figure 7 .
[0095] Figure 1 The SEM results of the transparent hydrogel dressing showed that there were a large number of micron-sized pores in the gel, which were beneficial to the gas exchange of the skin or wound tissues. The qualitative hydrogel was transparent and had strong formability.
[0096] Figure 2 Adhesion test results showed that the transparent hydrogel dressing prepared in Example 4 had high adhesion strength and low peeling force, and was easy to replace and clean.
[0097] Figure 3 The light transmittance results showed that the hydrogel dressings prepared in Examples 1-5 and Comparative Examples 1-2 had strong light transmittance, with a light transmittance of more than 80%, among which the hydrogel dressing prepared in Example 4 had the highest light transmittance.
[0098] Figure 4 The results of the gel swelling test showed that the hydrogel dressing prepared in Example 4 had the highest cross-linking density, restricted the penetration of water molecules, and had the lowest swelling rate. However, the hydrogel dressing prepared in Comparative Example 1 without the addition of modified PDA had a swelling rate of 480%. Its high water absorption easily caused the collapse of the three-dimensional network structure of the gel, resulting in reduced performance.
[0099] Figure 5 The cumulative release rate results showed that in the pH 5.5 environment, the GA release of the hydrogel dressing prepared in Example 4 was the slowest and the content was the lowest, which was conducive to the slow release of the drug in the skin microenvironment and had a sustained-release effect. In the pH 7.4 medium, the cumulative release rate of GA in Example 1 and Example 4 was higher and the release rate was faster, which was conducive to the rapid antibacterial and absorption of tissue fluid in the wound or skin defect area, the utilization of active substances in the gel, and the acceleration of wound healing. The prepared hydrogel dressing has pH responsiveness.
[0100] Figure 6 The cell viability results showed that the hydrogel dressings prepared in Examples 1-5 had good cell compatibility, while the hydrogel dressings prepared in Comparative Examples 1-2 lacked the deep cross-linking structure or the antioxidant protection of N,S-CDs and exhibited certain cytotoxicity.
[0101] Figure 7 The results of the cell scratch test showed that compared with the control group, the hydrogel dressing prepared in Example 4 could promote HUVEC cell migration and accelerate angiogenesis at the wound site.
[0102] While embodiments of the present invention have been shown and described, it will be appreciated by 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 invention, and that the scope of the invention is defined by the appended claims and their equivalents.
[0103] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and actual applications are not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, any method and embodiment similar to the technical solution without creative design shall fall within the scope of protection of the present invention.
Claims
1. A medical transparent hydrogel dressing, characterized in that: The invention comprises the following raw materials in parts by weight: 4-6 parts of citric acid, 2-3 parts of L-cysteine, 4-5.5 parts of chitosan, 0.8-1.5 parts of hyaluronic acid, 0.08-0.1 parts of MBA, 0.8-1.2 parts of modified PDA, 0.04 parts of photoinitiator and 100 parts of pH 6.5 PBS buffer solution; The modified PDA comprises the following raw materials in parts by weight: 0.4-0.48 parts of PCA, 0.2-0.24 parts of FeCl3·6H2O, 0.4-0.48 parts of DA, 0.2-0.24 parts of GA, 0.1 parts of trehalose, and 100 parts of pH 7.8 PBS buffer. The specific preparation method of the modified PDA comprises the following steps: S1: Weigh PCA and FeCl3·6H2O and dissolve them in pH 7.8 PBS buffer to obtain a coordination complex; S2: Weigh DA and GA and add them to the coordination complex to react and obtain GA-PDA polymer; S3: dialyze the GA-PDA polymer, add trehalose and freeze-dry to obtain modified PDA; The preparation method of the medical transparent hydrogel dressing is as follows: Step 1: Weigh citric acid and L-cysteine, dissolve, react, dialyze, and freeze-dry to obtain N,S-CDs; Step 2: Weigh chitosan, hyaluronic acid, and MBA and dissolve them in pH 6.5 PBS buffer to obtain a gel matrix; Step 3: Weigh the modified PDA and N,S-CDs and add them into the gel matrix for dispersion treatment, then add a photoinitiator for curing to obtain a medical transparent hydrogel dressing.
2. A medical transparent hydrogel dressing according to claim 1, characterized in that: The DA is in the form of hydrochloride; In step S2, the reaction process is carried out at 4° C. in the dark; In step S3, the dialysis time is 24 hours, and the solution is changed every 8 hours.
3. The medical transparent hydrogel dressing according to claim 1, characterized in that: The photoinitiator is selected from any one of LAP, curcumin and vitamin B2.
4. The medical transparent hydrogel dressing according to claim 1, characterized in that: The chitosan has a deacetylation degree of 85%-90% and a molecular weight of 100-150 kDa.
5. The medical transparent hydrogel dressing according to claim 1, characterized in that: The hyaluronic acid comprises thiolated hyaluronic acid, and the degree of substitution of thiol groups thereof is 5-8%.
6. The medical transparent hydrogel dressing according to claim 1, characterized in that: In step 1, the reaction process is a hydrothermal reaction at 160° C. for 4 h; In step 3, the dispersion treatment process is performed by ultrasound, and after the solidification is completed, the mixture is incubated at 37° C. for 2 h.