Hydrogel dressing based on multiple synergistic mechanisms and preparation method

Abstract

The invention relates to the technical field of biomedical materials, in particular to a hydrogel dressing based on a multi-synergistic mechanism and a preparation method, the dressing is a GelMA-HTCC-Q [7] hydrogel dressing, the hydrogel dressing has a quadruple synergistic mechanism, and the hydrogel dressing is a hydrogel dressing. The quadruple synergistic mechanism comprises formation of a light-ion dual-network interpenetrating structure, a subject-object dynamic enhancement mechanism, a polyphenol-protein-polysaccharide multivalent cross-linking system and an interface oxidation-adhesion coupling effect; through a light-ion dual-network interpenetrating structure, a subject-object dynamic enhancement mechanism, a polyphenol-protein-polysaccharide multivalent cross-linking system and an interface oxidation-adhesion coupled quadruple synergistic mechanism, collaborative optimization of wet adhesion, mechanical adaptability, volume stability and long-acting antibacterial activity is realized, and the degradation speed is proper; the dressing can be gradually degraded along with wound healing, and the situation that acidic products damage local microenvironment balance is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomedical materials, and particularly relates to a hydrogel dressing based on a multiple synergistic mechanism and a preparation method. BACKGROUND

[0002] Skin and oral mucosa wounds are common clinical conditions. Studies have shown that when the area of oral mucosa defect exceeds 1cm 2 or the skin appears full-thickness defect, the self-healing ability of the tissue will significantly decrease, and the risk of infection will greatly increase. At this time, a dressing is usually needed to cover and protect the wound to promote tissue repair. The clinical treatment of oral mucosa defects is particularly complex: on the one hand, the moist environment and complex microbial community in the oral cavity make the exposed wound without the protection of the stratum corneum more susceptible to microbial invasion; on the other hand, the accumulation of wound exudate and the mechanical friction caused by frequent chewing movements will hinder the regeneration of epithelial tissue. These special physiological environments put higher requirements on the performance of the dressing.

[0003] Traditional wound dressings mainly include gauze, gelatin sponge and biological membrane, etc. These dressings have limitations in oral and skin wound management. Gauze dressings need to be sutured and fixed in the oral cavity, and in skin wounds, they are easy to adhere to the exudate, causing secondary damage. Gelatin sponge is easy to swell excessively in a humid environment, and its mechanical strength can decrease by more than 70% within 48 hours. In addition, most of the current wound dressings have insufficient adhesion durability, especially for intraoral wounds and skin wounds with more exudation. Related clinical studies have reported that about 60% of wound cases with more exudation have dressing displacement within 3 days after surgery. In this case, on the one hand, the dressing cannot effectively protect the wound, and on the other hand, the effective components in the dressing that promote wound healing cannot work well.

[0004] The key problems that need to be solved by an ideal wound dressing are how to achieve long-term strong adhesion on a moist tissue surface, how to achieve the stability of the material in a humid environment, and how to build a long-term antibacterial barrier. These are also the long-term pursuit of researchers.

[0005] GelMA-based hydrogel can form a stable three-dimensional network structure by photocrosslinking, and has excellent plasticity, biodegradability and good tissue biocompatibility. Because this kind of material can be endowed with additional activities such as promoting tissue healing, inhibiting bacteria and resisting infection by adding different active substances, it shows extremely high research value in the field of tissue engineering scaffold materials and wound mucosa materials. However, the addition of active ingredients usually affects the performance of GelMA-based hydrogel itself. In the research of GelMA-based hydrogel as oral mucosa and skin wound dressing, researchers often introduce dopamine, tannic acid, or silver nanoparticles and other active substances to enhance its adhesion, antibacterial and healing ability. However, these modification strategies still face challenges in the oral and skin wound environment. Oral mucosa and skin wounds with more exudation may be in a humid environment for a long time. For example, traditional GelMA dressing is easy to fall off under the erosion of saliva, and its adhesion strength is far lower than the threshold required by the dynamic movement of the oral cavity. Although the introduction of dopamine or tannic acid can improve adhesion, the oxidative crosslinking of polyphenolic substances (such as TA) is unstable in the body fluid environment, resulting in rapid decay of adhesion over time. In addition, oral and joint skin wounds require dressings with high tear strength to resist tongue movement or joint activity. However, the GelMA-related hydrogel network is easy to swell after absorbing water, resulting in a decrease in mechanical properties. In addition, the oral microbial environment is complex, and the antibacterial effect of existing GelMA dressing is difficult to persist. Silver nanoparticles or quaternary ammonium salt can provide broad-spectrum antibacterial properties, but the release of Ag + may cause cytotoxicity, and the combination of quaternary ammonium salt and saliva protein can reduce its antibacterial efficiency. In addition, photo-thermal antibacterial materials such as polydopamine halogen nanometer particles have difficulty in local temperature control in the oral cavity, and there is a risk of burns.

[0006] How to adjust the structure of GelMA-based hydrogel on the basis of its good moisturizing property and tissue compatibility, reasonably add active ingredients without reducing the performance of the material itself, and at the same time enhance its wet adhesion capacity, mechanical strength and volume stability in humid environment, and appropriate degradation rate is the key to promoting its use as an ideal wound dressing in clinical practice.

[0007] The existing GelMA-based hydrogel has various deficiencies when used as a dressing. First, the existing wound dressings, including GelMA-based hydrogel dressings, are easily affected by saliva flow, minor salivary gland secretion, and wound exudation in a moist oral environment and a skin wound environment with more exudation, resulting in insufficient adhesion, difficulty in effectively and stably fixing on the wound, and easy displacement or shedding of the dressing during oral function movement and skin rubbing, thereby weakening its long-term effect and affecting wound protection and treatment effect. Second, traditional dressings such as gauze, gelatin sponge, and biological membrane and GelMA-based hydrogel usually swell in volume after water absorption, resulting in significant changes in their physical properties and possible hardening or excessive swelling. At this time, not only is the patient's wearing comfort reduced, but also excessive mechanical pressure on the wound may interfere with the normal healing process of the wound. Although some studies have improved the above-mentioned dressing materials to increase softness, such improved materials have the disadvantage of insufficient tear resistance. Third, there are many types of microorganisms in the oral cavity and around the exposed skin wound, and the wound is easily invaded by bacteria, fungi, and other pathogens after exposure, increasing the risk of infection and possibly triggering local inflammatory reactions, further delaying the healing process. The reported GelMA-based oral dressings often lack broad-spectrum and long-acting antibacterial properties and are difficult to effectively inhibit microbial growth, resulting in insufficient protection of the dressing in actual application and affecting the recovery of the wound. Fourth, the existing wound dressing hydrogel still has deficiencies in swelling and degradation performance. In terms of swelling properties, highly chemically cross-linked hydrogels have excellent mechanical strength and adhesion properties, but their limited network structure significantly reduces the hydration capacity, resulting in problems such as decreased comfort and interface adhesion failure in clinical application. The hydrogel with low cross-linking density is prone to three-dimensional network structure collapse due to excessive swelling, and shows obvious structural instability in a humid dynamic environment. In terms of degradation behavior, natural polymer-based hydrogels are easily catalytically degraded by the saliva enzyme system; while synthetic polymer hydrogels have enzyme stability, but the presence of hydrolysis-sensitive groups in the molecular chain often leads to non-specific degradation, and the acidic small molecule products and incompletely reacted cross-linking agents produced during the degradation process may disrupt the physiological balance of the local oral microenvironment.

[0008] Therefore, in view of the above problems, the present application provides a hydrogel dressing based on a multiple synergistic mechanism and a preparation method thereof. SUMMARY

[0009] In order to overcome the deficiencies of the existing GelMA-based hydrogel when used as a dressing, such as wet adhesion performance, softness and tear resistance, maintenance of antibacterial effect, significant swelling, and rapid degradation, the present application provides a hydrogel dressing based on a multiple synergistic mechanism and a preparation method thereof.

[0010] The technical scheme of the present application is: a hydrogel dressing based on a multiple synergistic mechanism, comprising: the hydrogel dressing is a GelMA-HTCC-Q[7] hydrogel dressing, the hydrogel dressing has a quadruple synergistic mechanism, the hydrogel dressing can firmly and stably cover the oral mucosa wound by wet adhesion and isolate the oral environment stimulation, the dressing has soft texture but mechanical adaptability against tearing, and the dressing has a suitable degradation rate with wound healing.

[0011] As preferred, the quadruple synergistic mechanism comprises a photo-ion double network interpenetrating structure, a host-guest dynamic enhancement mechanism, a polyphenol-protein-polysaccharide multivalent crosslinking system, and an interface oxidation-adhesion coupling effect.

[0012] As preferred, the photo-ion double network interpenetrating structure is a topological interpenetrating structure formed by in-situ synchronous crosslinking technology of a photo-crosslinking network of methacrylated gelatin as a rigid skeleton and an ionic crosslinking network of chitosan quaternary ammonium salt, so that the photo-crosslinking network of GelMA and the ionic crosslinking network of HTCC synergistically act.

[0013] As preferred, the host-guest dynamic enhancement mechanism refers to the selective inclusion of a quaternary ammonium salt group on the HTCC chain by cucurbit[7]uril, to form a stable host-guest complex, which simultaneously serves as an antibacterial agent slow-release carrier and an energy dissipation unit.

[0014] As preferred, the polyphenol-protein-polysaccharide multivalent crosslinking system is a hydrogen bond network formed by tannic acid through phenolic hydroxyl groups and hydroxyl groups of HTCC and amino groups of GelMA, to form multiple non-covalent crosslinking.

[0015] As preferred, the interface oxidation-adhesion coupling effect is that the phenolic hydroxyl groups of tannic acid form a strong adhesion layer on the wet mucosa surface through dynamic oxidative crosslinking, while endowing the hydrogel with antioxidant and anti-inflammatory functions.

[0016] As preferred, a preparation method of the hydrogel dressing based on the multiple synergistic mechanism comprises the following steps:

[0017] S1, ultrasonic-assisted dispersion of HTCC in a phosphate buffer solution at pH 7.4, control of the final concentration of HTCC to be 0.4% w / v, and ensuring that there is no aggregate state.

[0018] S2, magnetic stirring dispersion of Q[7] in the same PBS system at a speed of 500-600 rpm for 10 min, control of the concentration of Q[7] to be 0.8% w / v, and sterilization filtration by using a 0.22 μm filter membrane.

[0019] S3, slowly drop the HTCC solution obtained in S1 into the Q[7] solution obtained in S2 at a rate of 0.5 mL / min, while maintaining the system at 65±5℃ and 550±50rpm magnetic stirring conditions for 8±2min, wherein the molar ratio of the repeating unit of HTCC to Q[7] is 1:3.5.

[0020] S4, mix 10%w / v GelMA, 0.2%w / v photo-initiator LAP and 1.2%w / v HTCC-Q[7] complex in a light-proof, 50-55℃ water bath, continuously stirring at 200rpm for 1.5±0.5h, until a bubble-free and optically transparent homogeneous solution is formed, wherein the amino substitution degree of GelMA is 60±5%, and the molecular weight is 100-200kDa.

[0021] S5, under light-proof conditions, drop 0.01%w / v tannic acid solution into the mixed system obtained in S4, while dynamically adjusting the pH to 5.5±0.5 by 0.1M HCl / NaOH, and maintaining 250±50rpm magnetic stirring for 30min, so that the tannic acid is uniformly dispersed and combined with the HTCC-Q[7] complex through multiple hydrogen bonds.

[0022] S6, inject the precursor solution into the mold, crosslink under the irradiation of 405nm blue light 10mW / cm 2 for 30±2s, forming a three-dimensional network structure with gradient crosslinking density.

[0023] As preferred, the process of the host-guest dynamic reinforcement mechanism is completed through steps S1-S3, the host-guest reaction occurs between the Q[7] cavity and the HTCC quaternary ammonium group, and the HTCC-Q[7] complex is obtained.

[0024] As preferred, the process of the photo-ion dual-network interpenetrating structure and the polyphenol-protein-polysaccharide multivalent crosslinking system is completed through steps S4-S6, after the HTCC is mixed with tannic acid, the quaternary ammonium group and the amino group of the HTCC simultaneously undergo ionic bond and hydrogen bond crosslinking during the photo-curing of GelMA, forming an interpenetrating network, while the tannic acid constructs a hydrogen bond network through the phenolic hydroxyl group and the hydroxyl group of HTCC and the amino group of GelMA, forming multiple non-covalent crosslinking.

[0025] As preferred, the process of the interface oxidation-adhesion coupling includes: after the GelMA, LAP and HTCC-Q[7] complex are pre-assembled in a homogeneous solution in PBS solution under light-proof conditions, adding a tannic acid solution and uniformly dispersing it by pH regulation and magnetic stirring.

[0026] The beneficial effects of the present application are:

[0027] 1.The hydrogel realizes the synergistic optimization of wet adhesion, mechanical adaptability, volume stability and long-acting antibacterial property through the four synergistic mechanisms of light-ion double network interpenetrating structure, host-guest dynamic enhancement mechanism, polyphenol-protein-polysaccharide multivalent cross-linking system and interface oxidation-adhesion coupling, and the degradation speed is suitable, which can gradually degrade with wound healing, avoiding the destruction of local microenvironment balance by acidic products.

[0028] 2.The precursor solution has fluidity, and when used, it needs to be injected to be uniformly distributed according to the size of the mucosal wound, and the wound is covered with the precursor solution, and a conventional oral light curing lamp is used to irradiate for 30 seconds to form a gel dressing firmly attached to the surface of the wound and fully isolated from environmental stimuli.

[0029] 3.The maximum tensile stress and strain of the composite hydrogel GelMA-HTCC-Q[7] of the application are 112.79kPa and 111%, which indicates that the hydrogel has good soft texture and high tear resistance.

[0030] 4.The hydrogel has excellent volume stability and mechanical property stability in a humid environment, and the swelling rate is only 2.2%, which is much lower than the 20.94% of the traditional GelMA hydrogel, and the maximum tensile stress can still reach 82.43kPa after being soaked in PBS for 24 hours, so that the dressing can be used for a long time in a humid environment without hardening or excessive swelling.

[0031] 5.The hydrogel has long-acting and broad-spectrum antibacterial property, and the antibacterial circle diameters of Staphylococcus aureus and Escherichia coli are 22.6mm and 19.3mm respectively, and the growth of bacteria can still be effectively inhibited after 7 days of application, which solves the problem that the oral and skin wounds are easily attacked by microorganisms, significantly reduces the risk of infection and promotes wound healing. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The preparation process schematic diagram of the application is shown;

[0033] Figure 2 The comparative experiment result schematic diagram of the application is shown Figure 1 ;

[0034] Figure 3 The comparative experiment result schematic diagram of the application is shown Figure 2 ;

[0035] Figure 4 The comparative experiment result schematic diagram of the application is shown Figure 3 ;

[0036] Figure 6The anti-bacterial performance test results of the GleMA, GelMA-HTCC-Q[7] hydrogel of the present application are shown in the schematic diagram.

[0037] Figure 7 The anti-bacterial performance test results of the GleMA, GelMA-HTCC-Q[7] hydrogel of the present application are shown in the schematic diagram.

[0038] Figure 8 The anti-bacterial performance test results of the GleMA, GelMA-HTCC-Q[7] hydrogel of the present application are shown in the schematic diagram.

[0039] Figure 1 The anti-bacterial performance test results of the GleMA, GelMA-HTCC-Q[7] hydrogel of the present application are shown in the schematic diagram. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0041] The present application provides an embodiment: a hydrogel dressing based on multiple synergistic mechanisms, which is a GelMA-HTCC-Q[7] hydrogel dressing that can firmly and stably cover the oral mucosa wound by wet adhesion, isolate the oral environment stimulation, has soft but tear-resistant mechanical adaptability, can maintain volume stability in a moist wound environment, has a suitable degradation rate as the wound heals, and can provide long-acting antibacterial effect.

[0042] Please refer to Figures 2-4 The present application provides an embodiment: a preparation method of a hydrogel dressing based on multiple synergistic mechanisms, which comprises the following steps:

[0043] S1, HTCC is ultrasonically assisted and dispersed in a phosphate buffer solution at pH 7.4, the final concentration of HTCC is controlled to be 0.4% w / v, and no aggregated state exists.

[0044] S2, Q[7] is dispersed by magnetic stirring at a speed of 500-600 rpm for 10 min in the same PBS system, the concentration of Q[7] is controlled to be 0.8% w / v, and 0.22 μm filter membrane is used for sterilization filtration.

[0045] S3, slowly add the HTCC solution obtained in S1 to the Q[7] solution obtained in S2 at a rate of 0.5 mL / min while maintaining the system at 65±5℃ and 550±50 rpm magnetic stirring for 8±2 min, wherein the molar ratio of the repeating unit of HTCC to Q[7] is 1:3.5.

[0046] S4, mix 10% w / v GelMA, 0.2% w / v photo-initiator LAP and 1.2% w / v HTCC-Q[7] complex in a light-proof, 50-55℃ water bath under gentle stirring at 200 rpm for 1.5±0.5 h until a bubble-free and optically transparent homogeneous solution is formed, wherein the amino substitution degree of GelMA is 60±5% and the molecular weight is 100-200 kDa.

[0047] S5, under light-proof conditions, add 0.01% w / v tannic acid solution dropwise to the mixed system obtained in S4 while dynamically adjusting the pH to 5.5±0.5 by 0.1 M HCl / NaOH and maintaining at 250±50 rpm magnetic stirring for 30 min to allow the tannic acid to be uniformly dispersed and combined with the HTCC-Q[7] complex through multiple hydrogen bonds.

[0048] S6, inject the precursor solution into the mold, crosslink under the irradiation of 405 nm blue light 10 mW / cm 2 for 30±2 s to form a three-dimensional network structure with gradient crosslinking density.

[0049] The obtained hydrogel precursor solution needs to be stored under light-proof conditions at a temperature less than or equal to 40℃, preferably under light-proof conditions at 4℃, and can be placed at 37℃ for 10 minutes before use to restore the liquid state of the hydrogel precursor solution.

[0050] Please refer to Figure 2 , Example 1, synthesis and structure identification of GelMA-HTCC-Q[7] hydrogel dressing:

[0051] Process of forming host-guest dynamic enhancement mechanism:

[0052] Thermogravimetric analysis was performed on HTCC, Q[7] and HTCC-Q[7] inclusion complex, and the results are shown in (f) of Figure 2 , HTCC rapidly loses mass at 264.44℃, Q[7] rapidly loses mass at 437.52℃, and HTCC-Q[7] rapidly loses mass at 451.14℃, which indicates that HTCC and Q[7] may form a complex.

[0053] Fourier transform infrared spectroscopy was performed on HTCC, Q[7] and HTCC-Q[7] inclusion complex, and the results are shown inFigure 2 As shown in (e) of FIG. 10, compared with the HTCC group, the peak near 950 cm-1 of the HTCC-Q[7] inclusion complex disappeared, which might be due to the restriction of the C-N bond vibration after HTCC and Q[7] formed the inclusion complex; and the peak near 3400 cm-1 of the HTCC-Q[7] inclusion complex shifted to a lower wave number, which might be due to the formation of new hydrogen bonds between the -OH of HTCC and the port oxygen of Q[7]; in addition, the new peak near 1635 cm-1 of the inclusion complex came from the interaction between the quaternary ammonium group of HTCC and the carbonyl oxygen of Q[7]; and compared with the HTCC group, the characteristic peak intensity of the HTCC-Q[7] group decreased to different degrees, which might be due to the formation of host-guest inclusion complex between Q[7] and the quaternary ammonium group of HTCC.

[0054] Photo-ion dual-network interpenetrating structure and polyphenol-protein-polysaccharide multivalent cross-linking system process:

[0055] Fourier transform infrared spectroscopy was performed on the GleMA, GelMA-HTCC, and GelMA-HTCC-Q[7] hydrogels, and the results are shown in FIG. 11. Figure 3 As shown in (d) of FIG. 11, compared with the GleMA group, the new peak near 1036 cm-1 of the GelMA-HTCC and GelMA-HTCC-Q[7] hydrogel groups came from the sugar ring skeleton vibration of HTCC. The 1730 cm-1 peak in the GelMA-HTCC-Q[7] hydrogel group came from the carbonyl (C=O) stretching vibration of Q[7], and the 806 cm-1 peak came from the molecular framework vibration of Q[7]. In addition, Fourier transform infrared spectroscopy was performed on HTCC, and the results are shown in FIG. 12. Figure 4 The FT-IR characteristic peaks at 1647 and 1478 cm-1 indicated the presence of amino groups and quaternary amino groups in the HTCC chain, and these two peaks disappeared in the GelMA-HTCC and GelMA-HTCC-Q[7] hydrogels, which might be due to the formation of ionic bonds and hydrogen bonds between the quaternary ammonium and amino groups of HTCC and the hydroxyl groups of tannic acid; and compared with the GelMA hydrogel group, the GelMA-HTCC-Q[7] hydrogel group had a wider absorption band in the 3000-3500 cm -1 interval, indicating that the hydroxyl groups of HTCC, the amino groups of GelMA, and the phenolic hydroxyl groups of tannic acid all participated in the hydrogen bond network.

[0056] Interface oxidation-adhesion coupling process: The in vitro wet bonding performance of the GleMA, GelMA-HTCC-Q[7] hydrogels with tannic acid and the corresponding hydrogels without tannic acid was tested, and the results are shown in FIG. 13. Figure 3As shown in (b) of FIG. 6, the wet adhesion of the group with tannic acid is significantly improved compared to the groups G and GHQ without tannic acid, and is higher than the dry adhesion. This indicates that the presence of tannic acid allows the hydrogel to form a strong adhesion layer on the mucosal surface in the wet state.

[0057] GleMA, GelMA-HTCC, and GelMA-HTCC-Q[7] hydrogels soaked in PBS at 37°C for different times were subjected to sputter coating and then scanned under a scanning electron microscope. The results are shown in FIG. 5. Figure 3 As shown in (a) of FIG. 6, the GleMA hydrogel exhibits an irregular, highly interconnected porous structure with relatively thick pore walls. The GelMA-HTCC and GelMA-HTCC-Q[7] hydrogels, on the other hand, exhibit a more regular and denser porous structure with relatively thin pore walls. This is likely because the addition of HTCC forms a double network structure with GelMA, increasing the overall crosslinking density of the hydrogel and thus forming a denser porous structure. This change can improve the mechanical strength of the hydrogel, reducing the likelihood of deformation and rupture, and can also reduce the evaporation rate of water in the hydrogel, improving its moisturizing ability. Meanwhile, the thinner pore walls can reduce the restriction on water molecules in the hydrogel, thus increasing the softness of the hydrogel. The GelMA hydrogel disintegrates after 48 hours of soaking, while the GelMA-HTCC-Q[7] hydrogel still maintains its network structure after 72 hours of soaking, indicating that the GelMA-HTCC-Q[7] hydrogel can persist in a humid environment.

[0058] See Figure 3 Example 2, Cell Compatibility Test:

[0059] The cell compatibility of the GleMA and GelMA-HTCC-Q[7] hydrogels was tested using the Cell Counting Kit-8 (CCK-8) method. Since fibroblasts play an important role in the healing of alveolar bone and gingival mucosa, fibroblasts were used for the experiment, and were cultured in hydrogel conditioned medium and ordinary medium.

[0060] 1 g of sterile hydrogel was soaked in 10 mL of serum-free Dulbecco's modified Eagle's medium (DMEM) at 37°C for 24 hours to prepare a hydrogel extract. The extract was filtered and diluted with serum-free medium at a ratio of 1:3, and serum was added according to the ratio. The cells were incubated at 37°C for 24 hours at 2000 cells per well in a 96-well plate. The cell culture medium was replaced with the hydrogel extract, and incubation was continued for 24 and 48 hours. After incubation, the culture medium in the 96-well plate was removed, and CCK-8 reagent was added to each well for 2 hours of incubation. The absorbance was measured at 450 nm using a microplate reader to assess cell proliferation. Each group was measured in triplicate. The final results are shown in FIG. 7.Figure 3 The proliferation behavior of each group of cells was similar, and no statistically significant difference was observed between the hydrogel group and the blank control group after 24 and 48 hours of culture. This indicates that the GelMA-HTCC-Q[7] hydrogel has good cell compatibility.

[0061] See Figure 3 , Example 3, Anti-tear strength performance test:

[0062] The mechanical properties of the GelMA and GelMA-HTCC-Q[7] groups of hydrogels were tested using a micro-mechanical tester (UniVert S2, CellScale, Canada). The tensile strength of the hydrogel samples was tested at room temperature. The hydrogels were all dumbbell-shaped with a length of 35 mm and a thickness of 2 mm. The samples were stored in a sealed container before testing to avoid long-term contact with air. The tensile rate was 1 mm / s. The test results are shown in Figure 3 As shown in (b) of the foregoing table, the tensile strength of the hydrogel is determined by the stress at the time of sample fracture. The maximum tensile stress and strain of the control group were 62.89 kPa and 55%, respectively, while those of the composite hydrogel GelMA-HTCC-Q[7] were 112.79 kPa and 111%, respectively. The data show that the hydrogel prepared by the present application exhibits good soft texture while maintaining a high anti-tear strength compared to the GelMA hydrogel.

[0063] See Figure 3 , Example 4, Anti-swelling performance test:

[0064] The GelMA and GelMA-HTCC-Q[7] groups of hydrogels were immersed in PBS at 37°C. The hydrogels were all square-shaped with a side length of 1 cm and a thickness of 3 mm. The mass changes at 2 hours, 4 hours, 6 hours, 8 hours, 12 hours, and 24 hours were recorded and compared by plotting. The results are shown in Figure 3 As shown in (d) of the foregoing table, after 24 hours of immersion, the hydrogels were removed and subjected to mechanical tensile performance testing to test the mechanical properties of the swollen hydrogels. The results are shown in Figure 3 As shown in (e) of the foregoing table, according to (d) of the foregoing table, after 24 hours of immersion in PBS at 37°C, the swelling rate of the GelMA-HTCC-Q[7] group was significantly lower than that of the GelMA group. In addition, as shown in (e) of the foregoing table, the mechanical tensile properties of the swollen GelMA-HTCC-Q[7] hydrogel were better than those of the GelMA hydrogel group, and the difference was small compared to before swelling. These results all indicate that the GelMA-HTCC-Q[7] hydrogel has excellent anti-swelling properties and good stability in a humid environment. Figure 3 Figure 3

[0065] Figure 4 ​​(d) of FIG. 6 shows the anti-swelling performance of the composite hydrogel GelMA-HTCC-Q[7] and the control group GelMA hydrogel. Both groups of hydrogels reached swelling equilibrium after about 12 hours, with a swelling rate of 20.94% and 2.2%, respectively. The data show that the hydrogel prepared by the present application has little volume change in a humid environment, and the anti-swelling performance is greatly improved compared with the GelMA hydrogel. In addition, Figure 4 (e) of FIG. 6 shows the maximum tensile strength test results of the composite hydrogel GelMA-HTCC-Q[7] and the control group GelMA hydrogel before and after soaking in 37°C PBS for 24 hours. The maximum tensile stress before and after soaking is 62.89 kPa, 25.31 kPa; 112.79 kPa, 82.43 kPa, respectively. These data show that the hydrogel prepared by the present application can maintain the stability of mechanical properties in a humid environment.

[0066] Referring to Figure 4 , Example 5, in vitro wet adhesion performance test:

[0067] The in vitro wet adhesion performance of GleMA, GelMA-HTCC-Q[7] hydrogel was tested by lap shear test.

[0068] Prepare pig skin pieces, and apply 200 μL of hydrogel precursor to the 1 cm x 1 cm cut pieces of the two pig skins, and crosslink under ultraviolet light for 30 seconds. Use a micro-mechanical tester (UniVert S2, CellScale, Canada, maximum load of weighing sensor is 10 N), and the strain rate of the tensile test is 1 mm / s. The lap shear strength is determined by the pulling force when the hydrogel is separated from the pig skin. Take another hydrogel sample and pig skin pieces, and perform lap shear test under wet conditions. The final results are shown in Figure 5 (a) of FIG. 7, in a dry environment, the lap shear strengths of the three groups of hydrogels are 7.371 kPa, 5.818 kPa, and 1.495 kPa, respectively. And in a humid environment, they are 13.184 kPa, 0.507 kPa, and 4.131 kPa, respectively. The results show that the wet adhesion performance of the GelMA-HTCC-Q[7] group is significantly improved compared with the GleMA group and the commercial oral dressing product Gengigel, and is higher than that in a dry environment. This indicates that the GelMA-HTCC-Q[7] hydrogel has good wet adhesion performance, thereby allowing it to maintain stable adhesion with the oral mucosa in a humid environment in the mouth.

[0069] Another pigskin pieces, pig liver tissue and pig tongue tissue pieces, all made into 2 cm long, 1 cm wide, 4 mm thick rectangular, 200 μL of hydrogel precursor coated on the 1 cm x 1 cm section of two pieces of tissue, cross-linked under UV light for 30 seconds, soaked in artificial saliva for different times, and then tested by a micro-mechanical tester (UniVert S2, CellScale, Canada, maximum load of weighing sensor is 10 N), the strain rate of tensile test is 1 mm / s, and the lap shear strength is determined by the tensile force when the hydrogel is separated from the tissue skin. The lap shear strength of the composite hydrogel GelMA-HTCC-Q[7] and the control hydrogel GelMA soaked in artificial saliva for different times is shown in Figure 6 (c) of the present application. The composite hydrogel GelMA-HTCC-Q[7] and different tissues are bonded, and the bonding force is still present after soaking in artificial saliva for 72 hours, which is significantly better than the control hydrogel GelMA.

[0070] See Figure 5 and Figure 5 , Example 6, antibacterial performance test:

[0071] Escherichia coli and Staphylococcus aureus are used as representative gram-negative and gram-positive bacteria, and are cultured in the conditions of GelMA, GelMA-HTCC-Q[7] hydrogel medium and blank medium.

[0072] In this embodiment, the antibacterial effect of the hydrogel material is evaluated by using colony counting experiment, specifically:

[0073] A portion of the colonies is picked up in a solid culture medium and resuspended in 10 ml of liquid culture medium. A 6 mm diameter hydrogel material is immersed in 1 mL of Staphylococcus aureus / Escherichia coli culture solution and incubated at 37°C on a shaking table for 24 hours. 100 μL of culture solution is taken, and the bacterial solution is diluted to 10-5 times. Then 100 μL of bacterial solution is taken and spread on the corresponding agar medium. After incubation overnight, the number of colonies on the agar plate is counted. The final results are shown in Figure 5 (b) and (d) of the present application.

[0074] In this embodiment, the antibacterial effect of the hydrogel material is evaluated by using a modified Kirby-Bauer disc diffusion test, specifically:

[0075] 100 μL of Staphylococcus aureus / Escherichia coli (107 CFU / mL) was evenly dispersed on a TSB / LB agar plate. Subsequently, a 6 mm diameter hydrogel dressing disc was adhered to the agar medium and incubated at 37°C for 24 hours. After incubation, inhibition zones appeared on the agar plate, and their diameters were measured. A 6 mm diameter circular filter paper disc immersed in PBS was placed on the agar plate as a blank medium. Bacterial growth in the standard medium, control group, and experimental hydrogel medium was compared and analyzed. The final results are shown in Figures 5(a) and (c).

[0076] according to Figure 6 As shown in the results (b) and (d) in Figure 3, dense bacterial colonies were observed in the blank control group and the GleMA group after overnight incubation, while in the group treated with GelMA-HTCC-Q[7] hydrogel, few bacterial colonies grew on the plate. Figures 6-8 As shown in the results (a) and (c), after 24 hours of incubation, no obvious inhibition zone was observed in the blank group and the GleMA group, while the diameter of the inhibition zone of Staphylococcus aureus in the GelMA-HTCC-Q[7] group was 22.6 mm, and the diameter of the inhibition zone of Escherichia coli was 19.3 mm. Figure 6 As shown in the data, the composite hydrogel still had an inhibitory effect on Staphylococcus aureus and Escherichia coli after 7 days of application. These results indicate that the hydrogel prepared by this patent has a good antibacterial effect and can play an effective antibacterial and anti-infection effect when used as an intraoral wound dressing.

[0077] See also Figure 6 Example 7: In vivo wound healing performance test:

[0078] This example tests the wound healing performance of oral ulcers in rats, specifically:

[0079] It is planned to select 8-week-old SD rats, use an 18G needle or a sterile scalpel to gently scrape the target mucosal area 3-5 times until slight bleeding occurs, and then take another 70% acetic acid solution. Use a circular filter paper with a diameter of 4mm soaked in acetic acid to stick on the oral mucosa of the rat on both sides for 60s, remove the filter paper and rinse it three times with normal saline. After 24 hours, obvious ulcers are formed with a diameter of about 2-4mm. The center of the ulcer area is white and necrotic, and the surrounding area is congested and swollen. The hydrogel dressing of the experimental group is adhered to the wound, and the control group is not treated to allow it to heal naturally. The redness, swelling and pain of the oral mucosa are observed for several days after administration, and the diameter of the ulcer surface is measured and statistically processed. The performance of the composite hydrogel GelMA-HTCC-Q[7] in promoting the healing of rat oral ulcers is shown in the following figure, compared with the control group hydrogel GelMA and the commercial oral dressing hydrogel Gengigel positive control group. Figure 7(b) of FIG. 6, the healing rate of the composite hydrogel GelMA-HTCC-Q[7] dressing group was faster than that of the untreated group, the negative and positive control groups. The results showed that the hydrogel prepared in the present patent had good effect on promoting wound healing. ​ (b) of FIG. 6, the healing rate of the composite hydrogel GelMA-HTCC-Q[7] dressing group was faster than that of the untreated group, the negative and positive control groups. The results showed that the hydrogel prepared in the present patent had good effect on promoting wound healing.

[0080] The skin wound healing promoting performance of rats was tested in this example, and the specific steps were as follows:

[0081] SD rats of 8 weeks old were selected, the hair on the back of the rats was shaved, and the remaining short hair was removed with depilatory cream. Iodophor and 75% alcohol were used alternately for disinfection. The wound area was marked with a marker pen, and the wound was a circle with a diameter of 6 mm and a depth of 2 mm. The skin was completely removed by surgical scissors, and the muscle fascia was exposed. The gauze was pressed lightly to stop bleeding, and the wound was washed with sterile normal saline. The hydrogel dressing of the experimental group was adhered to the wound, and the control group was not treated to heal naturally, and the redness and pain of the wound were observed on several days after administration, and the ulcer diameter was measured and statistically processed. The performance of the composite hydrogel GelMA-HTCC-Q[7] in promoting the healing of rat oral ulcers was as follows: ​ (a) of FIG. 6, the healing rate of the composite hydrogel GelMA-HTCC-Q[7] dressing group was faster than that of the untreated group, the negative and positive control groups. The results showed that the hydrogel prepared in the present patent had good effect on promoting wound healing.

[0082] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in other forms. Any person skilled in the art can make modifications or changes to the equivalent embodiments of the above disclosed technical contents, and apply them to other fields, but any simple modification, equivalent change and alteration made to the above embodiments without departing from the technical solution of the present application, and according to the technical essence of the present application, still belong to the protection scope of the technical solution of the present application.

Claims

1. Hydrogel dressing based on multiple synergistic mechanisms, characterized in that, The hydrogel dressing comprises a GelMA-HTCC-Q[7] hydrogel dressing, which has a quadruple synergistic mechanism, can firmly and stably cover the oral mucosa wound and isolate the oral environment stimulation through wet adhesion, has soft but tear-resistant mechanical adaptability, and has a suitable degradation rate as the dressing heals with the wound.

2. The hydrogel dressing based on multiple synergistic mechanisms according to claim 1, characterized in that: The quadruple synergistic mechanism comprises a photo-ion double network interpenetrating structure, a host-guest dynamic enhancement mechanism, a polyphenol-protein-polysaccharide multivalent cross-linking system, and an interface oxidation-adhesion coupling effect.

3. The hydrogel dressing based on multiple synergistic mechanisms according to claim 1, characterized in that: The photo-ion double network interpenetrating structure is a topological interpenetrating structure formed by in-situ synchronous crosslinking of a photo-crosslinked network of methacrylated gelatin as a rigid skeleton and an ionic crosslinked network of chitosan quaternary ammonium salt, so that the photo-crosslinked network of GelMA and the ionic crosslinked network of HTCC synergize.

4. The hydrogel dressing based on multiple synergistic mechanisms according to claim 1, characterized in that: The host-guest dynamic enhancement mechanism refers to the selective inclusion of the quaternary ammonium salt groups on the HTCC chain by cucurbit[7]uril to form a stable host-guest complex, which simultaneously serves as an antibacterial agent release carrier and an energy dissipation unit.

5. The hydrogel dressing based on multiple synergistic mechanisms according to claim 1, characterized in that: The polyphenol-protein-polysaccharide multivalent cross-linking system is a hydrogen bond network formed by tannic acid through phenolic hydroxyl groups and hydroxyl groups of HTCC and amino groups of GelMA, forming multiple non-covalent cross-linking.

6. The hydrogel dressing based on multiple synergistic mechanisms according to claim 1, characterized in that: The interface oxidation-adhesion coupling effect is that the phenolic hydroxyl groups of tannic acid form a strong adhesion layer on the wet mucosa surface through dynamic oxidative crosslinking, while also endowing the hydrogel with antioxidant and anti-inflammatory functions.

7. A method for the preparation of a hydrogel dressing based on multiple synergistic mechanisms according to any one of claims 1-6, characterized in that, The method comprises the following steps: S1, ultrasonic-assisted dispersion of HTCC in a phosphate buffer solution at pH 7.4, control the final concentration of HTCC to be 0.4% w / v, and ensure that there is no aggregation state. S2, magnetic stirring dispersion of Q[7] in the same PBS system at a speed of 500-600 rpm for 10 min, control the concentration of Q[7] to be 0.8% w / v, and use a 0.22 μm filter to sterilize and filter. S3, slowly drop the HTCC solution obtained in S1 into the Q[7] solution obtained in S2 at a rate of 0.5 mL / min, while maintaining the system at 65±5℃ and 550±50 rpm magnetic stirring conditions for 8±2 min, wherein the molar ratio of HTCC repeat units to Q[7] is 1:3.

5. S4, mix 10% w / v GelMA, 0.2% w / v photoinitiator LAP, and 1.2% w / v HTCC-Q[7] complex in a light-proof, 50-55℃ water bath, continuously stir at a speed of 200 rpm for 1.5±0.5 h, until a bubble-free and optically transparent homogeneous solution is formed, wherein the amino substitution degree of GelMA is 60±5%, and the molecular weight is 100-200 kDa. S5, under light-proof conditions, add 0.01% w / v tannic acid solution dropwise to the mixed system obtained in S4, while dynamically adjusting the pH to 5.5±0.5 by 0.1 M HCl / NaOH, and maintaining at 250±50 rpm magnetic stirring for 30 min, so that the tannic acid is uniformly dispersed and combined with the HTCC-Q[7] complex through multiple hydrogen bonds. S6, the precursor solution is injected into the mold, and cross-linked under the irradiation of 405 nm blue light 10 mW / cm 2 for 30±2 s to form a three-dimensional network structure with gradient cross-linking density.

8. The method of claim 7, wherein the hydrogel dressing based on the multiple synergistic mechanisms is prepared by the steps of: The process of the host-guest dynamic enhancement mechanism is completed through steps S1-S3, the Q[7] cavity and the HTCC quaternary ammonium group undergo host-guest reaction to obtain an HTCC-Q[7] complex.

9. The method of claim 7, wherein the hydrogel dressing based on the multiple synergistic mechanisms is prepared by the steps of: The process of the light-ion double-network interpenetrating structure and the polyphenol-protein-polysaccharide multivalent cross-linking system is completed through steps S4-S6, after the HTCC is mixed with the tannic acid, the quaternary ammonium group and the amino group of the HTCC simultaneously undergo ionic bond and hydrogen bond cross-linking during the light curing of the GelMA to form an interpenetrating network, and meanwhile the tannic acid forms a hydrogen bond network through the phenolic hydroxyl group and the hydroxyl group of the HTCC and the amino group of the GelMA to form multiple non-covalent cross-linking.

10. The method of claim 7, wherein the hydrogel dressing based on the multiple synergistic mechanisms is prepared by the steps of: The process of the interface oxidation-adhesion coupling includes: after the GelMA, the LAP and the HTCC-Q[7] complex are pre-assembled to form a homogeneous solution in a PBS solution under light shielding conditions, a tannic acid solution is added and uniformly dispersed through pH regulation and magnetic stirring.

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