Multifunctional heterogeneous hydrogel as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of biomedical materials, and discloses a multifunctional heterogeneous hydrogel which comprises an AlgMA / NBC / TA / Ce-MOF hydrogel and an AlgMA / NBC / TA / Ce-MOF (at) Ins hydrogel. The invention also discloses a preparation method and application of the two hydrogels. According to the invention, methylacrylated sodium alginate / bacterial cellulose (AlgMA / BC) is used as basic gel and is mixed with a cerium-based organic metal framework (Ce-MOF) wrapped by tannic acid (TA), so that the hydrogel is endowed with excellent oxidation resistance and inflammation resistance. On the basis of preparation of ABTC hydrogel, Ce-MOF with a large specific surface area is used as a drug carrier to load insulin, an outer layer is wrapped by tannic acid (TA), and wound inflammatory response and immune microenvironment are improved by exerting excellent antibacterial and antioxidant properties of the tannic acid, so that healing of diabetic wounds is effectively promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical materials, and in particular relates to a multifunctional heterogeneous hydrogel, a preparation method and applications thereof. Background Art

[0002] With the continued rise in the number of people with diabetes worldwide, diabetic wound healing has become a significant public health challenge. Diabetic patients often experience slow chronic wound healing, primarily due to microvascular damage and increased oxidative stress caused by hyperglycemia, which makes wounds susceptible to infection and difficult to heal. Therefore, finding effective treatments to promote diabetic wound healing has become a pressing clinical and research challenge.

[0003] Sodium alginate (Alg) can be modified and processed to give it photocrosslinking ability and excellent water solubility. The hydrophilicity of sodium alginate enables it to quickly absorb wound exudate, forming a moist environment and promoting hemostasis; its biological activity can stimulate cell migration and angiogenesis, accelerating wound healing. Therefore, sodium alginate has become an ideal material in fields such as tissue engineering, drug carriers and wound dressings. Although sodium alginate is widely used in the biomedical field, its lack of antibacterial effect limits its further application.

[0004] Based on this, we propose a multifunctional heterogeneous hydrogel, its preparation method and its application. Summary of the Invention

[0005] The first object of the present invention is to provide a multifunctional heterogeneous hydrogel.

[0006] A multifunctional heterogeneous hydrogel, wherein the hydrogel is an AlgMA / NBC / TA / Ce-MOF hydrogel.

[0007] A multifunctional heterogeneous hydrogel, wherein the hydrogel is AlgMA / NBC / TA / Ce-MOF@Ins hydrogel.

[0008] The second object of the present invention is to provide a method for preparing a multifunctional heterogeneous hydrogel, which is used to prepare the above-mentioned AlgMA / NBC / TA / Ce-MOF hydrogel, and specifically comprises the following steps:

[0009] (1) Preparation of methacrylated sodium alginate:

[0010] Weigh 1-3g Alg and add it to 100mL aqueous solution and stir until it is fully dissolved to form a 1%-3% sodium alginate solution. Place the Alg aqueous solution in an ice bath and slowly add a certain amount of methacrylic anhydride. React in the dark for 24 hours. During the reaction, continuously add 5M NaOH to adjust the pH to maintain it at around 7-8. After the reaction is completed, transfer the reaction solution to an 8-14KDa dialysis bag and dialyze it with deionized water for about 5-7 days, changing the water frequently every day to remove unreacted anhydride and by-products. Finally, freeze-dry the dialyzed solution for 48 hours to obtain a white sponge-like product, methacrylated sodium alginate.

[0011] (2) Preparation of bacterial cellulose:

[0012] After 7 days of fermentation and cultivation of Acetobacter xylinum, a bacterial cellulose membrane was obtained. The culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried. The BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added at a mass ratio of 1:3. Hydrolysis was carried out with vigorous stirring at 40-50°C for 100-150 minutes, and the suspension was diluted with excess distilled water to terminate the reaction. Then, high-speed centrifugation was performed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution. The sediment was collected and dialyzed with distilled water until a constant neutral pH was reached. Finally, the suspension was freeze-dried for 48 hours to obtain bacterial cellulose.

[0013] (3) Synthesis of cerium MOF:

[0014] A certain volume of 0.1-0.3 mM cerium nitrate (Ce(NO3)3-6H2O) solution was added dropwise to an aqueous solution of 0.1-0.3 mM 1,3,5-benzenetricarboxylic acid (BTC) and 0.3-0.5 mM triethylamine (TEA), and the reaction was carried out for 5-20 minutes. The product was collected by centrifugation at 9000 rpm, washed alternately with ethanol and water three times, and finally dried in an oven at 60°C to obtain Ce-MOF.

[0015] (4) Preparation of AlgMA / NBC / TA / Ce-MOF hydrogel

[0016] The above-mentioned BC powder and methacrylated sodium alginate were mixed evenly in a mass ratio of 1:3, 1-2% tannic acid (TA) was added to wrap the dried Ce-MOF powder, and ultrasonic stirring was performed evenly. Then 0.15% LAP was added, and ultraviolet cross-linking was performed for 1-3 minutes using an ultraviolet lamp with an intensity of 395 nm to form a hydrogel. The obtained hydrogel was AlgMA / NBC / TA / Ce-MOF hydrogel.

[0017] The third object of the present invention is to provide a method for preparing a multifunctional heterogeneous hydrogel, which is used to prepare the above-mentioned AlgMA / NBC / TA / Ce-MOF@Ins hydrogel, and specifically comprises the following steps:

[0018] (1) Preparation of methacrylated sodium alginate:

[0019] Weigh 1-3g of Alg and add it to 100mL of aqueous solution, stirring until fully dissolved to form a 1%-3% sodium alginate solution. Place the Alg aqueous solution in an ice bath and slowly add a certain amount of methacrylic anhydride. The reaction is allowed to react for 24 hours in the dark. During the reaction, 5M NaOH is continuously added dropwise to adjust the pH to maintain it at around 7-8. After the reaction is complete, transfer the reaction solution to an 8-14kDa dialysis bag and dialyze it against deionized water for approximately 5-7 days, changing the water frequently daily to remove unreacted anhydride and byproducts. Finally, the dialyzed solution is freeze-dried for 48 hours to obtain a white, spongy product, methacrylated sodium alginate.

[0020] (2) Preparation of bacterial cellulose:

[0021] After 7 days of fermentation and cultivation of Acetobacter xylinum, a bacterial cellulose membrane was obtained. The culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried. The BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added at a mass ratio of 1:3. Hydrolysis was carried out with vigorous stirring at 40-50°C for 100-150 minutes, and the suspension was diluted with excess distilled water to terminate the reaction. Then, high-speed centrifugation was performed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution. The sediment was collected and dialyzed with distilled water until a constant neutral pH was reached. Finally, the suspension was freeze-dried for 48 hours to obtain bacterial cellulose.

[0022] (3) Synthesis of cerium MOF:

[0023] A certain volume of 0.1-0.3 mM cerium nitrate (Ce(NO3)3-6H2O) solution was added dropwise to an aqueous solution of 0.1-0.3 mM 1,3,5-benzenetricarboxylic acid (BTC) and 0.3-0.5 mM triethylamine (TEA), and the reaction was carried out for 5-20 minutes. The product was collected by centrifugation at 9000 rpm, washed alternately with ethanol and water three times, and finally dried in an oven at 60°C to obtain Ce-MOF.

[0024] (4) Preparation of AlgMA / NBC / TA / Ce-MOF@Ins hydrogel

[0025] The dried Ce-MOF powder was added to a 5-10 mg / ml insulin solution and sonicated for 10-50 minutes to ensure uniform dispersion and adequate drug loading. 1-2% tannic acid (TA) was then added to coat the Ce-MOF. Bacterial cellulose and methacrylated sodium alginate were then added at a 1:3 mass ratio. After stirring, 0.15% lithium phenyl (2,4,6-trimethylbenzoyl) phosphate (LAP) was added. After UV crosslinking for 1-3 minutes using a 395 nm UV lamp, the AlgMA / NBC / TA / Ce-MOF@Ins hydrogel was formed.

[0026] A fourth objective of the present invention is to use AlgMA / NBC / TA / Ce-MOF hydrogel for wound treatment. ABTC hydrogel has excellent antioxidant and anti-inflammatory properties, effectively inhibiting wound infection and promoting wound healing. While this hydrogel has shown some improvement in the healing of chronic diabetic wounds, there is still room for improvement.

[0027] A fifth objective of the present invention is to use AlgMA / NBC / TA / Ce-MOF@Ins hydrogel for wound treatment in diabetic patients. ABTC@Ins hydrogel incorporates insulin into the ABTC hydrogel. This, in addition to ABTC's excellent antioxidant and anti-inflammatory properties, allows it to lower blood glucose levels in wounds. Animal experiments have shown that ABTC@Ins hydrogel can promote the basic healing of chronic diabetic wounds within 10 days, complete wound healing within 15 days, and normal hair growth, making it an excellent hydrogel dressing for chronic diabetic wounds.

[0028] The present invention has the following beneficial effects:

[0029] The present invention adopts a physical blending method to skillfully combine sodium alginate with other biocompatible materials to design two new multifunctional heterogeneous hydrogel dressings, aiming to provide more effective solutions for the treatment of common wounds and diabetic wounds.

[0030] First, we chemically modified sodium alginate and synthesized methacrylated sodium alginate (AlgMA) to give sodium alginate the ability to photocrosslink, so that it can form a stable three-dimensional network structure through ultraviolet light-induced polymerization. In order to improve the mechanical properties of the hydrogel, AlgMA was mixed with bacterial cellulose (BC). Methacrylated sodium alginate / bacterial cellulose (AlgMA / BC) was used as a base gel and mixed with tannic acid (TA)-coated cerium-based organic metal framework (Ce-MOF), giving the hydrogel excellent antioxidant and anti-inflammatory properties, resulting in a composite hydrogel AlgMA / NBC / TA / Ce-MOF (abbreviated as ABTC) with anti-inflammatory and antioxidant functions. 。

[0031] Secondly, based on the preparation of ABTC hydrogel, Ce-MOF with a large specific surface area was used as a drug carrier to load insulin, and the outer layer was wrapped with tannic acid (TA) to give the hydrogel the properties of diabetes sustained release and hypoglycemic effect, thus obtaining another composite hydrogel AlgMA / NBC / TA / Ce-MOF@Ins (abbreviated as ABTC@Ins) with antibacterial, anti-inflammatory, antioxidant and hypoglycemic functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 These are the infrared and nuclear magnetic hydrogen spectra of AlgMA and Alg of the present invention.

[0033] Figure 2 1 and 2 are SEM, FTIR and XRD diagrams of the BC of the present invention and the BC after acid hydrolysis.

[0034] Figure 3 This is a TEM image of the Ce-MOF of the present invention.

[0035] Figure 4 It is the FTIR spectrum of BTC and Ce-MOF of the present invention.

[0036] Figure 5 These are the standard curves of the insulin of the present invention and the drug release curves of ABTC1@Ins, ABTC2@Ins and ABTC3@Ins3 hydrogels.

[0037] Figure 6 These are photos showing the DPPH radical scavenging rates of AB, ABT, ABTC, and ABTC@Ins of the present invention, as well as the reactions of different hydrogels with DPPH and ABTS.

[0038] Figure 7 These are pictures showing the antibacterial activities of the control group, AB, ABT, ABTC and ABTC@Ins of the present invention against Escherichia coli and Staphylococcus aureus determined by the plate count method.

[0039] Figure 8 is the bacterial survival rate of the control group, AB, ABT, ABTC and ABTC@Ins of the present invention.

[0040] Figure 9 This is the immunofluorescence staining analysis of IL-6 and IL-1β in the different treatment groups of the present invention on the 5th and 15th days.

[0041] Figure 10 This is the quantitative analysis of IL-6 and IL-1β in different treatment groups of the present invention on the 5th and 15th days.

[0042] Figure 11 This is the immunofluorescence staining analysis of TNFα and CD206 in the different treatment groups of the present invention on the 5th and 15th days.

[0043] Figure 12 This is the quantitative analysis of TNFα and CD206 in different treatment groups of the present invention on the 5th and 15th days.

[0044] Figure 13 These are live-dead cell staining images of L929 mouse fibroblasts co-cultured with the hydrogel for 1, 2, and 4 days.

[0045] Figure 14 is the cell survival rate of the L929 mouse fibroblasts of the present invention co-cultured with the hydrogel for 1, 2 and 4 days.

[0046] Figure 15 These are representative images and model diagrams of the wound healing of animals treated with different hydrogels under the conditions of 0, 5, 10, and 15 days in the present invention. DETAILED DESCRIPTION

[0047] Example 1 Preparation of AlgMA / NBC / TA / Ce-MOF composite hydrogel dressing

[0048] A method for preparing a multifunctional heterogeneous hydrogel for preparing an AlgMA / NBC / TA / Ce-MOF composite hydrogel dressing specifically comprises the following steps:

[0049] (1) Preparation of methacrylated sodium alginate:

[0050] Weigh 1-3g of Alg and add it to 100mL of aqueous solution, stirring until fully dissolved to form a 1%-3% sodium alginate solution. Place the Alg aqueous solution in an ice bath and slowly add a certain amount of methacrylic anhydride. In the dark, react for 24 hours. During the reaction, continuously add 5M NaOH dropwise to adjust the pH to around 7-8. After the reaction, transfer the reaction solution to an 8-14kDa dialysis bag and dialyze it against deionized water for approximately 5-7 days, changing the water frequently daily to remove unreacted anhydride and byproducts. Finally, freeze-dry the dialyzed solution for 48 hours to obtain a white, spongy product, methacrylated sodium alginate.

[0051] (2) Preparation of bacterial cellulose:

[0052] After 7 days of fermentation and cultivation of Acetobacter xylinum, a bacterial cellulose membrane was obtained. The culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried. The BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added at a mass ratio of 1:3. Hydrolysis was carried out with vigorous stirring at 40-50°C for 100-150 minutes, and the suspension was diluted with excess distilled water to terminate the reaction. Then, high-speed centrifugation was performed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution. The sediment was collected and dialyzed with distilled water until a constant neutral pH was reached. Finally, the suspension was freeze-dried for 48 hours to obtain bacterial cellulose.

[0053] (3) Synthesis of cerium MOF:

[0054] A certain volume of 0.1-0.3 mM cerium nitrate (Ce(NO3)3-6H2O) solution was added dropwise to an aqueous solution of 0.1-0.3 mM 1,3,5-benzenetricarboxylic acid (BTC) and 0.3-0.5 mM triethylamine (TEA), and the reaction was carried out for 5-20 minutes. The product was collected by centrifugation at 9000 rpm, washed alternately with ethanol and water three times, and finally dried in an oven at 60°C to obtain Ce-MOF.

[0055] (4) Preparation of AlgMA / NBC / TA / Ce-MOF hydrogel:

[0056] The above-mentioned BC powder and methacrylated sodium alginate were mixed evenly in a mass ratio of 1:3, 1-2% tannic acid (TA) was added to wrap the dried Ce-MOF powder, and ultrasonic stirring was performed evenly. Then 0.15% LAP was added, and ultraviolet cross-linking was performed for 1-3 minutes using an ultraviolet lamp with an intensity of 395 nm to form a hydrogel. The obtained hydrogel was the AlgMA / NBC / TA / Ce-MOF composite hydrogel dressing.

[0057] Ce-MOF was successfully prepared, such as Figure 3 、 4 shown.

[0058] Example 2 Application of AlgMA / NBC / TA / Ce-MOF composite hydrogel dressing in wound healing

[0059] A circular wound 8 mm in diameter was created on the back skin of diabetic mice. Sterilized liquid ABTC hydrogel was applied to the wound and irradiated with UV light for 1-3 minutes. The wound was then secured with a bandage and kept clean. The wound was regularly observed and scrubbed with saline and a cotton swab. The hydrogel dressing was changed every 2-3 days. A control group received no treatment. Wound healing was analyzed using ImageJet on days 5, 10, and 15.

[0060] Compared with the control group, wounds treated with ABTC hydrogel had formed scabs by day five, their area had significantly decreased by day 10, and they were essentially healed on day 15, leaving only a small scar. This demonstrates that ABTC hydrogel has a certain effect in promoting the healing of chronic diabetic wounds, but there is still room for improvement. ABTC can also be applied to normal wounds to promote their healing.

[0061] Example 3 Preparation of AlgMA / NBC / TA / Ce-MOF@Ins hydrogel

[0062] A method for preparing a multifunctional heterogeneous hydrogel, which is used to prepare AlgMA / NBC / TA / Ce-MOF@Ins hydrogel, specifically comprises the following steps:

[0063] (1) Preparation of methacrylated sodium alginate:

[0064] Weigh 1-3g of Alg and add it to 100mL of aqueous solution, stirring until fully dissolved to form a 1%-3% sodium alginate solution. Place the Alg aqueous solution in an ice bath and slowly add a certain amount of methacrylic anhydride. In the dark, react for 24 hours. During the reaction, continuously add 5M NaOH dropwise to adjust the pH to around 7-8. After the reaction, transfer the reaction solution to an 8-14kDa dialysis bag and dialyze it against deionized water for approximately 5-7 days, changing the water frequently daily to remove unreacted anhydride and byproducts. Finally, freeze-dry the dialyzed solution for 48 hours to obtain a white, spongy product, methacrylated sodium alginate.

[0065] (2) Preparation of bacterial cellulose:

[0066] After 7 days of fermentation and cultivation of Acetobacter xylinum, a bacterial cellulose membrane was obtained. The culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried. The BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added at a mass ratio of 1:3. Hydrolysis was carried out with vigorous stirring at 40-50°C for 100-150 minutes, and the suspension was diluted with excess distilled water to terminate the reaction. Then, high-speed centrifugation was performed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution. The sediment was collected and dialyzed with distilled water until a constant neutral pH was reached. Finally, the suspension was freeze-dried for 48 hours to obtain bacterial cellulose.

[0067] (3) Synthesis of cerium MOF:

[0068] A certain volume of 0.1-0.3 mM cerium nitrate (Ce(NO3)3-6H2O) solution was added dropwise to an aqueous solution of 0.1-0.3 mM 1,3,5-benzenetricarboxylic acid (BTC) and 0.3-0.5 mM triethylamine (TEA), and the reaction was carried out for 5-20 minutes. The product was collected by centrifugation at 9000 rpm, washed alternately with ethanol and water three times, and finally dried in an oven at 60°C to obtain Ce-MOF.

[0069] (4) Preparation of AlgMA / NBC / TA / Ce-MOF@Ins hydrogel

[0070] The dried Ce-MOF powder was added to a 5-10 mg / ml insulin solution and sonicated for 10-50 minutes to ensure uniform dispersion and adequate drug loading. 1-2% tannic acid (TA) was then added to coat the Ce-MOF. Bacterial cellulose and methacrylated sodium alginate were then added in a 1:3 mass ratio. After stirring, 0.15% lithium phenyl (2,4,6-trimethylbenzoyl) phosphate (LAP) was added. After UV crosslinking for 1-3 minutes using a 395 nm UV lamp, the AlgMA / NBC / TA / Ce-MOF@Ins hydrogel was formed.

[0071] Example 4 Application of AlgMA / NBC / TA / Ce-MOF@Ins hydrogel in wound healing

[0072] A circular wound with a diameter of 8 mm was created on the back skin of diabetic mice. Sterilized liquid ABTC@Ins hydrogel was applied to the wound and irradiated with UV light for 1-3 minutes. The wound was fixed with a bandage and kept clean. The wound was regularly observed and cleaned with saline and cotton swabs. The hydrogel dressing was changed every 2-3 days. The control group received no treatment. Pictures were taken on the 5th, 10th, and 15th days, and the wound healing status was analyzed using Image J.

[0073] Compared with the control group, the wounds treated with ABTC@Ins hydrogel had scabbed and reduced in area on the fifth day, were basically healed on the 10th day, and the scabs showed signs of falling off. They were completely healed on the 15th day, and the hair around the wounds grew vigorously, close to the surrounding healthy skin, proving that ABTC@Ins hydrogel is a hydrogel material that can be used to treat chronic diabetic wounds in a targeted manner.

[0074] Comparative Example 1 Preparation of AlgMA / NBC composite hydrogel

[0075] Preparation of AlgMA / NBC composite hydrogel includes the following preparation steps:

[0076] (1) Preparation of methacryloylated sodium alginate: Weigh 1-3 g of Alg and add it to 100 mL of aqueous solution, stirring until it is fully dissolved to form a 1%-3% sodium alginate solution. Place the Alg aqueous solution in an ice bath and slowly add a certain amount of methacrylic anhydride. The reaction is carried out in the dark for 24 hours. During the reaction, 5M NaOH is continuously added dropwise to adjust the pH to maintain it at around 7-8. After the reaction is completed, the reaction solution is transferred to an 8-14 kDa dialysis bag and dialyzed with deionized water for about 5 days, with frequent water changes every day to remove unreacted anhydride and by-products. Finally, the dialyzed solution is freeze-dried for 48 hours to obtain a white sponge-like product, methacryloylated sodium alginate.

[0077] (2) Preparation of bacterial cellulose: Bacterial cellulose membrane was obtained after 7 days of fermentation and cultivation of Acetobacter xylinum. The culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried. The BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added at a mass ratio of 1:3. Hydrolysis was carried out under vigorous stirring at 40-50°C for 100-150 minutes, and the suspension was diluted with excess distilled water to terminate the reaction. Then, high-speed centrifugation was performed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution. The sediment was collected and dialyzed with distilled water until a constant neutral pH was reached. Finally, the suspension was freeze-dried for 48 hours to obtain bacterial cellulose.

[0078] (3) The above-mentioned BC powder and methacrylated sodium alginate were mixed evenly in a mass ratio of 1:3, 0.15% LAP was added, and ultraviolet cross-linking was performed using an ultraviolet lamp with an intensity of 395 nm for 1-3 minutes to form a hydrogel. The obtained hydrogel was the AlgMA / NBC composite hydrogel dressing.

[0079] AlgMA and NBC were successfully prepared, such as Figure 1 , Figure 2 The AlgMA / NBC composite hydrogel has good cell compatibility. Figure 13 、 14 As shown, its antioxidant, antibacterial and anti-inflammatory properties are not satisfactory, such as Figure 6 、 7 , 8, 9, 10, 11, and 12, but it also has a certain effect on promoting wound healing in diabetic mice, e.g. Figure 15 shown.

[0080] Comparative Example 2 Preparation of AlgMA / NBC / TA composite hydrogel

[0081] Preparation of AlgMA / NBC / TA composite hydrogel includes the following preparation steps:

[0082] (1) Preparation of methacryloylated sodium alginate: Weigh 1-3 g of Alg and add it to 100 mL of aqueous solution, stirring until it is fully dissolved to form a 1%-3% sodium alginate solution. Place the Alg aqueous solution in an ice bath and slowly add a certain amount of methacrylic anhydride. The reaction is carried out in the dark for 24 hours. During the reaction, 5M NaOH is continuously added dropwise to adjust the pH to maintain it at around 7-8. After the reaction is completed, the reaction solution is transferred to an 8-14 kD dialysis bag and dialyzed with deionized water for about 5-7 days, with frequent water changes every day to remove unreacted anhydride and by-products. Finally, the dialyzed solution is freeze-dried for 48 hours to obtain a white sponge-like product, methacryloylated sodium alginate.

[0083] (2) Preparation of bacterial cellulose: Bacterial cellulose membrane was obtained after 7 days of fermentation and cultivation of Acetobacter xylinum. The culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried. The BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added at a mass ratio of 1:3. Hydrolysis was carried out under vigorous stirring at 40-50°C for 100-150 minutes, and the suspension was diluted with excess distilled water to terminate the reaction. Then, high-speed centrifugation was performed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution. The sediment was collected and dialyzed with distilled water until a constant neutral pH was reached. Finally, the suspension was freeze-dried for 48 hours to obtain bacterial cellulose.

[0084] (3) The above-mentioned BC powder and methacrylated sodium alginate were mixed evenly in a mass ratio of 1:3, 1-2% tannic acid (TA) was added, and stirred evenly. Then 0.15% LAP was added, and ultraviolet cross-linking was performed for 1-3 minutes using an ultraviolet lamp with an intensity of 395 nm to form a hydrogel. The obtained hydrogel was the AlgMA / NBC / TA composite hydrogel dressing.

[0085] AlgMA / NBC / TA composite hydrogel has excellent antioxidant, antibacterial and anti-inflammatory properties, such as Figure 6 、 7 , 8, 9, 10, 11, and 12 show good cell compatibility, e.g. Figure 13 、 14 As shown in Figure 2, it can promote wound healing in diabetic mice to a certain extent. Figure 15 shown.

[0086]

[0087]

[0088] The AlgMA / NBC / TA / Ce-MOF hydrogel proposed in the present invention has excellent antioxidant and anti-inflammatory properties, can remove ROS around the wound, promote the transformation of macrophages from the pro-inflammatory stage to the anti-inflammatory stage, and accelerate wound healing.

[0089] The AlgMA / NBC / TA / Ce-MOF@Ins hydrogel proposed in the present invention introduces insulin on the basis of ABTC hydrogel. While having antibacterial, anti-inflammatory and antioxidant capabilities, it can also reduce the blood glucose concentration around the wound and specifically treat chronic diabetic wounds.

[0090] The two hydrogels disclosed in this patent have two molding methods. Liquid hydrogel can be directly extruded near the wound and formed by UV cross-linking, or solid hydrogel that fits the shape of the wound can be printed using 3D printing. Both molding methods ensure the conformability of the hydrogel to the wound shape and can ensure its application in complex wound environments.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multifunctional heterogeneous hydrogel, characterized in that: The hydrogel is AlgMA / NBC / TA / Ce-MOF hydrogel.

2. A multifunctional heterogeneous hydrogel, characterized in that: The hydrogel is AlgMA / NBC / TA / Ce-MOF@Ins hydrogel.

3. A method for preparing a multifunctional heterogeneous hydrogel, for preparing the hydrogel according to claim 1, characterized in that: The steps include: (1) Preparation of methacrylated sodium alginate: The Alg aqueous solution was placed in an ice bath and methacrylic anhydride was added. The reaction was carried out in the dark. During the reaction, 5M NaOH was continuously added dropwise to adjust the pH to maintain at 7-8. After the reaction, the reaction solution was transferred to an 8-14 kDa dialysis bag and dialyzed with deionized water for 5-7 days, with the water being frequently changed daily to remove unreacted anhydride and by-products. The dialyzed solution was freeze-dried to obtain a white sponge-like product, methacrylated sodium alginate. (2) Preparation of bacterial cellulose: Acetobacter xylinum was fermented to obtain bacterial cellulose membrane; the culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried; the BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added; Hydrolyze vigorously with stirring at 40-50°C for 100-150 min, dilute the suspension with excess distilled water to terminate the reaction; Centrifuge at high speed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution; The sediment was collected and dialyzed against distilled water until a constant neutral pH was reached; the suspension was freeze-dried to obtain bacterial cellulose; (3) Synthesis of cerium MOF: A 0.1-0.3 mM cerium nitrate (Ce(NO3)3-6H2O) solution was added dropwise to an aqueous solution of 0.1-0.3 mM 1,3,5-benzenetricarboxylic acid (BTC) and 0.3-0.5 mM triethylamine (TEA), and the mixture was reacted for 5-20 minutes. The product was collected by centrifugation at 9000 rpm, washed alternately with ethanol and water, and dried in an oven at 60°C to obtain Ce-MOF. (4) Preparation of AlgMA / NBC / TA / Ce-MOF hydrogel The above-mentioned BC powder and methacrylated sodium alginate were mixed evenly in a mass ratio of 1:3, 1-2% tannic acid (TA) was added to wrap the dried Ce-MOF powder, and ultrasonic stirring was performed. Then 0.15% LAP was added, and ultraviolet cross-linking was performed for 1-3 minutes using an ultraviolet lamp with an intensity of 395 nm to form an AlgMA / NBC / TA / Ce-MOF hydrogel.

4. A method for preparing a multifunctional heterogeneous hydrogel, for preparing the hydrogel according to claim 2, characterized in that: The steps include: (1) Preparation of methacrylated sodium alginate: The Alg aqueous solution was placed in an ice bath and methacrylic anhydride was added. The reaction was carried out in the dark. During the reaction, 5M NaOH was continuously added dropwise to adjust the pH to maintain at 7-8. After the reaction, the reaction solution was transferred to an 8-14 kDa dialysis bag and dialyzed with deionized water for 5-7 days, with the water being frequently changed daily to remove unreacted anhydride and by-products. The dialyzed solution was freeze-dried to obtain a white sponge-like product, methacrylated sodium alginate. (2) Preparation of bacterial cellulose: Acetobacter xylinum was fermented to obtain bacterial cellulose membrane; the culture medium on the surface of the BC membrane was removed using 1% NaOH and distilled water, and the BC membrane was freeze-dried; the BC membrane was ground into powder and 50% concentrated sulfuric acid (98%) was added; Hydrolyze vigorously with stirring at 40-50°C for 100-150 min, dilute the suspension with excess distilled water to terminate the reaction; Centrifuge at high speed several times to concentrate the bacterial cellulose crystals and remove excess acidic solution; The sediment was collected and dialyzed against distilled water until a constant neutral pH was reached; the suspension was freeze-dried for 48 hours to obtain bacterial cellulose; (3) Synthesis of cerium MOF: A certain volume of 0.1-0.3 mM cerium nitrate (Ce(NO3)3-6H2O) solution was added dropwise to an aqueous solution of 0.1-0.3 mM 1,3,5-benzenetricarboxylic acid (BTC) and 0.3-0.5 mM triethylamine (TEA), and the reaction was continued for 5-20 min. The product was collected by centrifugation at 9000 rpm, washed alternately with ethanol and water, and dried in an oven at 60°C to obtain Ce-MOF. (4) Preparation of AlgMA / NBC / TA / Ce-MOF@Ins hydrogel Ce-MOF powder was added to a solution containing 5-10 mg / ml of insulin and ultrasonically dispersed to fully load the drug; 1-2% tannic acid (TA) was then mixed in to wrap Ce-MOF; bacterial cellulose and methacrylated sodium alginate were added in a mass ratio of 1:3; after stirring evenly, 0.15% phenyl (2,4,6-trimethylbenzoyl) lithium phosphate (LAP) was added, and then ultraviolet cross-linking was carried out for 1-3 minutes using an ultraviolet lamp with an intensity of 395 nm to form AlgMA / NBC / TA / Ce-MOF@Ins hydrogel.

5. A multifunctional heterogeneous hydrogel, characterized in that: The hydrogel according to claim 1 is used for wound treatment.

6. A multifunctional heterogeneous hydrogel, characterized in that: The hydrogel as claimed in claim 2 is used for wound treatment in diabetic patients.

Images