A coffee acid-based double network hydrogel, hydrogel composite, and applications

Abstract

The application discloses a kind of double-network hydrogel based on coffee acid, and the double-network hydrogel is prepared by mixing gelatin grafted coffee acid and oxidized hyaluronic acid grafted meta-aminobenzoic acid after being dissolved in PBS respectively.By grafting coffee acid and meta-aminobenzoic acid on gelatin and oxidized hyaluronic acid respectively, the carboxyl group on coffee acid and the amino group on gelatin molecular chain, the amino group on meta-aminobenzoic acid and the carboxyl group on oxidized hyaluronic acid are coupled to form stable chemical bonds respectively, and the double-network structure is constructed by the dynamic covalent interaction between gelatin grafted coffee acid and oxidized hyaluronic acid grafted meta-aminobenzoic acid, which can quickly respond to mechanical disturbance and realize structure reconstruction while ensuring the strength and toughness of the hydrogel, and improve the adaptability and stability in the wound environment.

Description

Technical Field

[0001] This invention relates to the field of biomedical engineering technology, specifically to a caffeic acid-based dual-network hydrogel, hydrogel complex, and its applications. Background Technology

[0002] In recent years, the incidence of skin injuries has been rising annually, especially with a continuous increase in clinical cases of chronic wounds such as diabetic ulcers, burns, and infected wounds, making treatment increasingly urgent. Hydrogels, due to their high water content, three-dimensional network structure, and good biocompatibility, have been widely used in wound dressings and skin tissue engineering. The high water content of hydrogels helps maintain a moist wound environment and promotes the healing process. However, traditional hydrogels suffer from insufficient adaptability in the complex and dynamically changing wound microenvironment, such as poor mechanical properties and tissue matching, lack of environmental responsiveness, and difficulty in precisely controlling inflammatory responses and tissue repair processes, severely limiting their clinical translation and practical application. Therefore, developing intelligent hydrogels with microenvironment adaptability and multifunctionality has become an important direction in current skin regeneration and repair research.

[0003] Wound healing is a highly dynamic physiological process, typically involving four stages: hemostasis, inflammation, proliferation, and remodeling, accompanied by significant changes in indicators such as pH, enzyme activity, and oxidative stress levels within the microenvironment. To address this, researchers have developed various smart hydrogels with microenvironment-responsive properties, aiming to achieve precise intervention at different stages of wound healing. For example, pH-responsive hydrogels can sense the acidic environment of the wound site and regulate the gel swelling state through the proton absorption or release behavior of ionic groups on the polymer chains, thereby achieving controlled release. Enzyme-responsive hydrogels, by introducing specific enzyme-sensitive bonds or peptide sequences, achieve network degradation or structural alteration under the action of target enzymes, releasing loaded drugs or bioactive factors.

[0004] At the wound site, the massive aggregation and activation of immune cells are often accompanied by a significant increase in oxygen consumption and reactive oxygen species (ROS) levels, thereby exacerbating oxidative stress and further delaying tissue repair. ROS plays a crucial role in wound healing, but excessive ROS accumulation can lead to cell damage, excessive inflammatory response, and inhibition of cell proliferation and tissue regeneration. Therefore, ROS-responsive hydrogels have emerged. These hydrogels can selectively remove excess ROS and reduce oxidative damage, and can also trigger structural changes through ROS to achieve controlled release of loaded drugs or growth factors, thus playing a vital role in regulating immune status, promoting cell proliferation, and tissue regeneration. ROS-responsive hydrogels offer a novel treatment approach for chronic wound repair, but existing ROS-responsive hydrogels still face challenges such as poor long-term stability and difficulty in precisely controlling cellular biological functions. Especially in the complex and dynamically changing wound microenvironment, achieving precise regulation of cellular biological functions remains a pressing challenge.

[0005] To enhance the mechanical properties, self-healing capabilities, and multifunctional integration of materials, dynamically cross-linked dual-network hydrogels have garnered increasing attention. These hydrogels consist of two networks: one a stable framework network constructed through covalent bonds or physical interactions, and the other composed of dynamically reversible chemical bonds (such as Schiff base bonds, ester bonds, borate ester bonds, hydrogen bonds, and electrostatic interactions), endowing the material with excellent toughness, self-healing ability, and environmental responsiveness. Based on this structure, dynamically cross-linked dual-network hydrogels can achieve multifunctional integration, such as loading active molecules like antioxidants, growth factors, proteins, and nanoparticles, and possess the ability for slow release and precise regulation, showing promising application potential in promoting cell proliferation, anti-inflammatory regulation, and angiogenesis.

[0006] Chinese patent document CN119633164A discloses a temperature- and pH-responsive hydrogel loaded with chlorogenic acid liposomes. This hydrogel contains chlorogenic acid liposomes, modified gelatin grafted with phenylboronic acid, and oxidized hyaluronic acid grafted with dopamine. The concentration of the modified gelatin grafted with phenylboronic acid is 3-10 wt%, the concentration of the oxidized hyaluronic acid grafted with dopamine is 3-10 wt%, and the concentration of chlorogenic acid is 1-20 μM. This temperature- and pH-responsive hydrogel, alone or in combination with blue light, can effectively promote wound healing.

[0007] While dynamic dual-network hydrogels have made significant progress in improving the stability and functionality of hydrogels, challenges remain in addressing the complex and dynamically changing trauma microenvironment. Current technologies still have limitations in precisely controlling drug release rates and response speeds, thus necessitating the development of a more stable, intelligent, and responsive hydrogel system to changes in the trauma microenvironment. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a caffeic acid-based dual-network hydrogel. By forming amide and borate ester bonds between gelatin grafted with caffeic acid and oxidized hyaluronic acid grafted with m-aminophenylboronic acid, a dual-network structure of gel is constructed using multiple covalent interactions. While ensuring the strength and toughness of the hydrogel, it can quickly respond to mechanical disturbances and achieve structural reconstruction, thereby improving its adaptability and stability in trauma environments.

[0009] A caffeic acid-based dual-network hydrogel is prepared by dissolving gelatin grafted with caffeic acid and oxidized hyaluronic acid grafted with m-aminophenylboronic acid in PBS and then mixing them.

[0010] In this invention, caffeic acid and m-aminophenylboronic acid are grafted onto gelatin and oxidized hyaluronic acid, respectively. The carboxyl group on caffeic acid is coupled with the amino group on the gelatin molecular chain, and the amino group on m-aminophenylboronic acid is coupled with the carboxyl group on oxidized hyaluronic acid to form stable chemical bonds. The phenolic hydroxyl group on caffeic acid reacts with the borate group on m-aminophenylboronic acid to form a borate bond. The multiple dynamic covalent interactions between the two construct a double network structure of the gel. While ensuring the strength and toughness of the hydrogel, it can quickly respond to mechanical disturbances and achieve structural reconstruction, thereby improving its adaptability and stability in trauma environments.

[0011] Preferably, in the dual-network hydrogel, the mass percentage of gelatin grafted with caffeic acid is 2-40 wt%, and the mass ratio of the gelatin grafted with caffeic acid to the oxidized hyaluronic acid grafted with m-aminophenylboronic acid is 1-4:1-4.

[0012] In this invention, the gelation time of the dual-network hydrogel gradually shortens as the concentration of gelatin and oxidized hyaluronic acid in the hydrogel increases. When the gelatin grafted with caffeic acid and the oxidized hyaluronic acid grafted with m-aminophenylboronic acid in the dual-network hydrogel are within the above range, the elastic modulus of the dual-network hydrogel reaches 500~1500 MPa, and the hydrogel can balance strength and toughness.

[0013] More preferably, in the dual-network hydrogel, the mass percentage of gelatin grafted with caffeic acid is 5 wt%, and the mass ratio of the gelatin grafted with caffeic acid to the oxidized hyaluronic acid grafted with m-aminophenylboronic acid is 1:1.

[0014] In this invention, when the mass of gelatin grafted with caffeic acid and oxidized hyaluronic acid grafted with m-aminophenylboronic acid are both 5 wt%, the gelation time is the shortest, and the hydrogel strength and toughness are good.

[0015] This invention also provides a method for preparing the above-mentioned dual-network hydrogel, comprising the following steps:

[0016] (1) Gelatin and caffeic acid were coupled together under the action of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to obtain gelatin grafted with caffeic acid.

[0017] (2) Hyaluronic acid is oxidized to oxidized hyaluronic acid by sodium periodate. The oxidized hyaluronic acid is activated by 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholine chloride and then coupled with m-aminophenylboronic acid to obtain oxidized hyaluronic acid grafted with m-aminophenylboronic acid.

[0018] (3) The gelatin grafted with caffeic acid obtained in step (1) and the oxidized hyaluronic acid grafted with m-aminophenylboronic acid obtained in step (2) were dissolved in PBS solution and then mixed to obtain a caffeic acid-based double network hydrogel.

[0019] The present invention also provides a hydrogel complex in which the active ingredients are uniformly distributed in the above-mentioned caffeic acid-based dual-network hydrogel, wherein the active ingredients are nanoparticles loaded with nicotinamide adenine dinucleotide (NAD⁺) and / or CXC motif chemokine ligand 12 (CXCL12).

[0020] In this invention, NAD + The hydroxyl, carboxyl, and phosphate groups abundant in the basic unit of CXCL12 can form hydrogen bonds with the hydroxyl, carboxyl, or phenylboronic acid groups in caffeic acid-based dual-network hydrogels. Under the influence of ROS in a traumatic environment, these bonds break, triggering the deconstruction of the hydrogel complex and thus responsively achieving NAD. + With the release of CXCL12. CXCL12 recruits immune cells and promotes angiogenesis; NAD... + It promotes the polarization of macrophages into repair-type macrophages, and promotes cellular anti-inflammatory and antioxidant effects. These two effects can work individually or synergistically to improve the tissue damage microenvironment, synergistically promote wound closure, inhibit inflammation, enhance angiogenesis, and significantly improve the quality of tissue regeneration.

[0021] Meanwhile, the hydrogel complex can combine with changes in the wound microenvironment to regulate the initiation, rate and duration of active ingredient release, achieving precise drug delivery, and can also cover key stages of wound repair such as hemostasis, anti-inflammation, cell recruitment, angiogenesis and matrix remodeling.

[0022] More preferably, the active ingredient accounts for 0.5 to 5 wt% of the mass of the hydrogel complex.

[0023] More preferably, the active ingredient is a loaded NAD. +The nanoparticles and CXC motif chemokine ligand 12 in the caffeic acid-based dual-network hydrogel contain 5 wt% oxidized hyaluronic acid grafted with caffeic acid and 5 wt% grafted with m-aminophenylboronic acid.

[0024] In this invention, the above-mentioned hydrogel complex can synergistically release NAD. + And CXCL12, through which CXCL12 recruits immune cells, can promote angiogenesis; NAD + It promotes the polarization of macrophages into repair-type macrophages, enhances cellular anti-inflammatory and antioxidant effects, and the two work synergistically to promote wound closure, inhibit inflammation, enhance angiogenesis, and significantly improve the quality of tissue regeneration.

[0025] The present invention also provides a method for preparing the above-mentioned hydrogel composite, comprising the following steps:

[0026] The active ingredient was mixed with gelatin grafted with caffeic acid, and then mixed with oxidized hyaluronic acid grafted with m-aminophenylboronic acid to prepare a hydrogel complex.

[0027] The present invention also provides the application of the above-mentioned hydrogel complex in skin wound repair.

[0028] In the local area of ​​skin wounds, the large-scale aggregation and activation of immune cells are often accompanied by a significant increase in oxygen consumption and reactive oxygen species (ROS) levels, thereby exacerbating oxidative stress and further delaying tissue repair. The hydrogel composite of this invention can undergo structural changes under the action of ROS, thereby responsively achieving NAD... + With the release of CXCL12. CXCL12 recruits immune cells and promotes angiogenesis; NAD... + It promotes the polarization of macrophages into repair-type macrophages, and promotes cellular anti-inflammatory and antioxidant effects. These two effects can work individually or synergistically to improve the tissue damage microenvironment, synergistically promote wound closure, inhibit inflammation, enhance angiogenesis, significantly improve the quality of tissue regeneration, and thus promote the rapid healing of skin wounds.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] (1) The present invention constructs a dual network structure through the dynamic covalent interaction between gelatin grafted with caffeic acid and oxidized hyaluronic acid grafted with m-aminophenylboronic acid. While ensuring the strength and toughness of the hydrogel, it can quickly respond to mechanical disturbances and realize structural reconstruction, thereby improving the adaptability and stability in trauma environments.

[0031] (2) In this invention, NAD is loaded into the above-mentioned dual-network hydrogel. + And / or CXCL12, responsively enabling NAD in traumatic settings +With the release of CXCL12, through CXCL12 and NAD + It synergistically promotes wound closure, inhibits inflammation, enhances angiogenesis, and significantly improves the quality of tissue regeneration. Attached Figure Description

[0032] Figure 1 The diagram shows the synthetic route and verification diagram of gelatin grafted with caffeic acid in Example 1. In Example 1, A is the synthetic route of gelatin grafted with caffeic acid, and B and C are the 1H NMR spectrum and UV absorption spectrum of gelatin and gelatin grafted with caffeic acid, respectively.

[0033] Figure 2 This is the synthetic route and verification diagram of oxidized hyaluronic acid grafted with m-aminophenylboronic acid in Example 1. In this diagram, A is the synthetic route of oxidized hyaluronic acid grafted with m-aminophenylboronic acid in Example 1, and B to D are the infrared spectrum and 1H NMR spectrum of hyaluronic acid, oxidized hyaluronic acid, and oxidized hyaluronic acid grafted with m-aminophenylboronic acid, respectively.

[0034] Figure 3 The graphs show the gel time and elastic modulus of the double-network hydrogels prepared in Examples 1 to 4. In the graphs, A is the state graph of the double-network hydrogel of Example 1 before and after standing, B is the statistical graph of the gel time of the double-network hydrogels prepared in Examples 1 to 4, and C is the elastic modulus test graph of the double-network hydrogels prepared in Examples 1 to 4.

[0035] Figure 4 The images show the wound repair results of the dual-network hydrogel prepared in Example 1, the NAD-MOF@Gel prepared in Example 5, and the NAD-MOF-CXCL12@Gel prepared in Example 6 from 0 to 14 days of use. A shows the wound repair results on days 0, 3, 5, 7, 10, and 14 of use, and B is a statistical chart of the wound healing rate.

[0036] Figure 5 The images show HE staining and Masson trichrome staining images of the dual-network hydrogel prepared in Example 1, the NAD-MOF@Gel prepared in Example 5, and the NAD-MOF-CXCL12@Gel prepared in Example 6 on days 7 and 14, respectively. A is the HE staining image, and B is the Masson trichrome staining image.

[0037] Figure 6 The graphs show the statistical levels of cytokine expression after treatment with the dual-network hydrogel prepared in Example 1, the NAD-MOF@Gel prepared in Example 5, and the NAD-MOF-CXCL12@Gel prepared in Example 6. In the graphs, A to E are the statistical levels of expression of IL-1β, TNF-α, IL-6, TGF-β, and IL-10, respectively. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited to the following embodiments.

[0039] All raw materials used in this invention are commercially available.

[0040] Example 1

[0041] (1) Dissolve 1 g of gelatin in 100 mL of deionized water, and add 2.44 mg of caffeic acid, 382 mg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), and 230 mg of N-hydroxysuccinimide (NHS) sequentially to adjust the pH of the solution to 5.0. React the mixture overnight at room temperature under nitrogen protection. After the reaction, dialyze the reaction solution in deionized water for 3 days using a dialysis bag with a molecular weight cutoff of 8-14 kDa to remove unreacted small molecule impurities. After dialysis, freeze-dry the product to obtain caffeic acid-grafted gelatin (hereinafter referred to as CAG). The synthetic route is as follows: Figure 1 As shown in A in the diagram.

[0042] The chemical structure of CAG was determined by nuclear magnetic resonance hydrogen spectroscopy (NMR 1H spectroscopy). 1 H NMR confirmed ( Figure 1 (B in the image) By comparing the proton NMR spectra of gelatin and CAG, an absorption peak on the benzene ring of caffeic acid was observed at a shift of 6.2~7.2 ppm.

[0043] The degree of caffeic acid grafting can be determined by a UV-Vis spectrophotometer at 280 nm and 320 nm. Figure 1 (C in the middle).

[0044] (2) Weigh 2 g of hyaluronic acid (HA) and dissolve it in 100 mL of deionized water. Separately weigh 1.08 g of sodium periodate (NaIO4) and dissolve it in 6 mL of distilled water. Slowly add the solution dropwise to the HA solution under light-protected conditions and stir vigorously at room temperature for 4 hours to achieve the oxidation reaction. Then, add 1 mL of ethylene glycol and continue the reaction for 1 hour to terminate the excess periodic acid. Dialyze the resulting solution to deionized water for 3 days using a dialysis bag with a MWCO of 8-14 kDa, and then freeze-dry to obtain oxidized hyaluronic acid (OHA).

[0045] 1 g of OHA was dissolved in 100 mL of deionized water. Then, 2 g of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholine chloride (DMT-MM) and 1 g of m-aminophenylboronic acid (PBA) were added. The mixture was stirred at room temperature for 3 days, followed by dialyzing (MWCO 8~14 kDa) for 5 days. Finally, it was freeze-dried to obtain oxidized hyaluronic acid grafted with m-aminophenylboronic acid (hereinafter referred to as BOHA). The synthetic route is as follows: Figure 2 As shown in A in the diagram.

[0046] The chemical structure of BOHA was determined by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (NMR). 1 ¹H NMR confirmed the grafting, and FTIR spectra showed that OHA exhibited a characteristic C=O (aldehyde) peak at 1720 cm⁻¹; BOHA showed a distinct B–O stretching vibration peak (1330~1440 cm⁻¹), confirming successful PBA grafting; ¹H NMR spectra showed characteristic peaks of aromatic ring hydrogen in the 7.0~8.0 ppm range, which were hydrogen signals from PBA; compared to the spectrum of unmodified HA, BOHA showed an additional conjugated hydrogen signal, further proving successful coupling.

[0047] (3) Weigh 500 mg CAG and dissolve it in PBS to prepare 5 mL of 10 wt% CAG solution and 500 mg BOHA and dissolve it in PBS to prepare 5 mL of 10 wt% BOHA solution. Mix the above solutions and let them stand to form a caffeic acid-based double network hydrogel. Example

[0048] The preparation method is the same as in Example 1, with the following differences:

[0049] Table 1: Differences between caffeic acid-based dual-network hydrogels in Examples 1-4

[0050] Example 1 10 wt% 10 wt% Example 2 5 wt% 5 wt% Example 3 5 wt% 10 wt% Example 4 10 wt% 5 wt%

[0051] Example 5: Loaded NAD + Hydrogel complex of nanoparticles

[0052] (1) Preparation of NAD-loaded + nanoparticles

[0053] 1 mg of nicotinamide adenine dinucleotide (NAD⁺, purchased from Sigma-Aldrich, catalog number N3014) and 8 mg of zinc nitrate hexahydrate (Zn(NO₃)₂·6H₂O) were dissolved in 4 mL of deionized water and mixed thoroughly. Separately, 80 mg of 2-methylimidazole was dissolved in 4 mL of deionized water and then rapidly added to the above NAD⁺ solution. The mixture was shaken for 60 s and then allowed to stand for 4 hours to promote the self-assembly of metal-organic framework (MOF) nanostructures. After the reaction was complete, the precipitate was collected by centrifugation (10000×g, 30 min), and the supernatant was discarded. The resulting precipitate was the NAD⁺-loaded nanoparticle, abbreviated as NAD-MOF.

[0054] (2) Preparation of NAD-loaded + Hydrogel complex of nanoparticles

[0055] Take 20 mg of the loaded NAD obtained in step (1) + Nanoparticles were dissolved in 1 mL of CAG solution (10 wt%) to form a gel precursor solution. The gel precursor solution was then mixed with 1 mL of BOHA solution (10 wt%) to prepare NAD-loaded solution. + The hydrogel composite of nanoparticles (hereinafter referred to as NAD-MOF@Gel).

[0056] Example 6: Loaded NAD + Nanoparticles and CXCL12 hydrogel complex

[0057] (1) Preparation of NAD-loaded + The nanoparticles were prepared using the same method as in Example 5.

[0058] (2) Take 20 mg of the loaded NAD obtained in step (1) + Nanoparticles and 30 mg of CXCL12 (purchased from PeproTech, catalog number 250-20A) were dissolved in 1 mL of CAG solution (10 wt%) to form a gel precursor solution. The gel precursor solution was then mixed with 1 mL of BOHA solution (10 wt%) to prepare NAD-loaded solution. + The nanoparticles and CXCL12 hydrogel complex (hereinafter referred to as NAD-MOF-CXCL12@Gel).

[0059] Sample Analysis

[0060] I. Tests on hydrogels of different concentrations.

[0061] The gelation time and elastic modulus of the dual-network hydrogels in Examples 1-4 were tested.

[0062] Figure 3 Figures show the gel time and elastic modulus of the double-network hydrogels prepared in Examples 1-4. A represents the state of the double-network hydrogel of Example 1 before and after standing; B is a statistical graph of the gel time of the double-network hydrogels prepared in Examples 1-4; and C is a graph showing the elastic modulus of the double-network hydrogels prepared in Examples 1-4. As shown in the figures, the physical changes during the gel formation process can be visually observed before and after standing, from a solution state to a gel state. Figure 3 (A); Observing the effect of different component ratios on gelation speed and elastic modulus, it was found that the double-network hydrogel in Example 1 had the fastest gelation speed ( Figure 3 The hydrogel prepared by B has the best elastic modulus. Figure 3 (C in the middle).

[0063] II. Animal Skin Wound Repair Experiment

[0064] A full-thickness skin defect model (approximately 6 mm in diameter) on the back was established using 12-month-old Balb / c mice. The mice were randomly divided into four groups (n≥5 per group) and treated with different regimens. The bioactivity of the hydrogel in wound repair was compared. The four groups were:

[0065] Blank control group (G1): The wound was left untreated, and the natural healing process was observed;

[0066] Hydrogel matrix group (G2): The caffeic acid-based dual-network hydrogel prepared in Example 1 was used alone to evaluate the tissue repair promoting effect of the hydrogel material itself.

[0067] NAD-MOF nanoparticle-supported hydrogel assembly (G3): using the NAD-supported hydrogel prepared in Example 5. + A hydrogel composite of nanoparticles (NAD-MOF@Gel);

[0068] Combined CXCL12 protein and nanoparticle load group (G4): using NAD-loaded nanoparticles prepared in Example 6 + The nanoparticles and CXCL12 hydrogel complex (NAD-MOF-CXCL12@Gel).

[0069] The hydrogels G1 through G4 were prepared under aseptic conditions and applied to the wound immediately, changing them every two days for 14 consecutive days. Wounds were photographed on days 0, 3, 5, 7, 10, and 14, and the wound area was measured using ImageJ software to calculate the wound healing rate.

[0070] Figure 4The data shows the wound repair performance of the dual-network hydrogel prepared in Example 1, the NAD-MOF@Gel prepared in Example 5, and the NAD-MOF-CXCL12@Gel prepared in Example 6 over 0-14 days. A represents the wound repair performance on days 0, 3, 5, 7, 10, and 14, and B represents the wound healing rate. Figure 4 As shown in Figure A, the photographs of the wound healing status on days 0, 3, 5, 7, 10, and 14 for groups G1-G4 can visually reflect the healing process and speed. Figure 4 As shown in B, ImageJ was used to measure the wound area and calculate the healing percentage. At the same time point, the drug-loaded hydrogels in groups G3 and G4 significantly promoted wound healing better than the drug-unloaded blank hydrogel in group G2.

[0071] Wound tissue was collected for pathological and immunohistochemical analysis, including HE staining and Masson trichrome staining to assess epithelial remodeling and collagen deposition, as well as the expression levels of markers such as TNF-α, IL-6, TGF-β and IL-10, to comprehensively evaluate the regulatory capacity of each treatment group on different stages of wound repair (inflammatory phase, proliferative phase and remodeling phase).

[0072] Figure 5 Images of the double-network hydrogel prepared in Example 1, the NAD-MOF@Gel prepared in Example 5, and the NAD-MOF-CXCL12@Gel prepared in Example 6, after HE staining and Masson's trichrome staining on days 7 and 14, are shown. Image A is the HE staining image, and image B is the Masson's trichrome staining image. HE staining images of each treatment group on days 7 and 14 were used to observe the degree of epithelial remodeling and inflammatory cell infiltration. In the Masson's trichrome staining images at the corresponding time points, collagen deposition and remodeling of new tissue were clearly observed in group G4.

[0073] Figure 6 This is a statistical graph showing the cytokine expression levels in the wound healing microenvironment of different treatment groups. As shown in the figure, after treatment with NAD-MOF-CXCL12@Gel prepared in Example 6, the levels of IL-1β, TNF-α, and IL-6 decreased significantly, while the levels of TGF-β and IL-10 increased significantly.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hydrogel composite, characterized in that, The invention comprises an active ingredient and a caffeic acid-based dual-network hydrogel, wherein the active ingredient is uniformly distributed within the caffeic acid-based dual-network hydrogel. The active ingredients are NAD⁺-loaded nanoparticles and CXC motif chemokine ligand 12; the dual-network hydrogel is prepared by dissolving gelatin grafted with caffeic acid and oxidized hyaluronic acid grafted with m-aminophenylboronic acid in PBS and then mixing them. In the dual-network hydrogel, the mass percentage of gelatin grafted with caffeic acid is 2-40 wt%, and the mass ratio of gelatin grafted with caffeic acid to oxidized hyaluronic acid grafted with m-aminophenylboronic acid is 1-4:1-4.

2. The hydrogel composite according to claim 1, characterized in that, In the aforementioned dual-network hydrogel, the mass percentage of gelatin grafted with caffeic acid is 5 wt%, and the mass ratio of the gelatin grafted with caffeic acid to the oxidized hyaluronic acid grafted with m-aminophenylboronic acid is 1:

1.

3. The hydrogel composite according to claim 1 or 2, characterized in that, The method for preparing the caffeic acid-based dual-network hydrogel includes the following steps: (1) Gelatin and caffeic acid were coupled together under the action of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to obtain gelatin grafted with caffeic acid. (2) Hyaluronic acid is oxidized to hyaluronic acid by sodium periodate. After the hyaluronic acid is activated by 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholine chloride, it is coupled with m-aminophenylboronic acid to obtain hyaluronic acid grafted with m-aminophenylboronic acid. (3) The gelatin grafted with caffeic acid obtained in step (1) and the oxidized hyaluronic acid grafted with m-aminophenylboronic acid obtained in step (2) were dissolved in PBS solution and then mixed to obtain a caffeic acid-based double network hydrogel.

4. The hydrogel composite according to claim 1, characterized in that, The active ingredient accounts for 0.5 to 5 wt% of the mass of the hydrogel complex.

5. The hydrogel composite according to claim 1, characterized in that, The active ingredient is a loaded NAD. + The nanoparticles and CXC motif chemokine ligand 12 in the caffeic acid-based dual-network hydrogel contain 5 wt% gelatin grafted with caffeic acid and oxidized hyaluronic acid grafted with m-aminophenylboronic acid.

6. The method for preparing the hydrogel composite according to any one of claims 1 to 5, characterized in that, Includes the following steps: The active ingredient was mixed with a gelatin solution grafted with caffeic acid, and then mixed with an oxidized hyaluronic acid solution grafted with m-aminophenylboronic acid to prepare a hydrogel complex.

7. The application of the hydrogel composite according to any one of claims 1 to 5 in the preparation of skin wound repair materials.

Images