Metal-polyphenol network coated ZIF-8 synergistically modified collagenous fiber-based aerogel and preparation method thereof

Abstract

The invention discloses a preparation method of metal-polyphenol network coated ZIF-8 synergistically modified collagenous fiber-based aerogel. The preparation method comprises the following steps: step 1, preparing a metal organic framework compound ZIF-8; step 2, preparing ZIF-8 at TA dispersion liquid according to the product obtained in the step 1; step 3, preparing ZIF-8 (at) MPN dispersion liquid according to the product obtained in the step 2, and then washing and drying the ZIF-8 (at) MPN dispersion liquid; step 4, preparing a Col / CNF composite dispersion liquid; step 5, preparing a Col / CNF-ZIF-8 (at) MPN composite dispersion liquid according to products obtained in the step 3 and the step 4; and step 6, preparing the Col / CNF-ZIF-8 (at) MPN composite aerogel according to the product obtained in the step 5. The invention further discloses the metal-polyphenol network coated ZIF-8 synergistically modified collagenous fiber based aerogel and a preparation method of the metal-polyphenol network coated ZIF-8 synergistically modified collagenous fiber based aerogel. The problem that an existing gel material is poor in mechanical performance is solved.

Description

Technical Field

[0001] This invention belongs to the field of natural polymer materials technology, and relates to metal-polyphenol network-coated ZIF-8 synergistically modified collagen fiber-based aerogel. This invention also relates to a method for preparing metal-polyphenol network-coated ZIF-8 synergistically modified collagen fiber-based aerogel. Background Technology

[0002] Collagen fiber-based aerogels are novel porous materials with widely available, biodegradable, and excellent biocompatibility. Due to their abundant resources and unique triple-helix conformation, they hold great potential for applications in biomedicine and food packaging. However, their insufficient mechanical properties significantly limit their further application. ZIF-8 is based on Zn... 2+ Metal-organic frameworks (MOFs) with 2-methylimidazole as the organic ligand and tunable pore structure as the central ion have broad research prospects in the field of biomolecular materials due to their advantages such as tunable pore structure, excellent biocompatibility, and good antibacterial properties. In recent years, studies have shown that modifying MOFs with plant polyphenols can enhance their stability and surface reactivity, significantly improving their compatibility and reactivity with biomass materials. Therefore, by further crosslinking and reinforcing collagen networks with ZIF-8 nanocomposite particles modified with metal-polyphenol networks and cellulose nanofibers, collagen fiber-based composite aerogels can be prepared. This can enhance the mechanical strength of collagen fiber-based aerogels and holds promise for applications in biomedical fields such as wound hemostatic materials. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing ZIF-8 synergistically modified collagen fiber-based aerogels coated with metal-polyphenol networks, which solves the problem of poor mechanical properties in existing gel materials.

[0004] Another object of the present invention is to provide a metal-polyphenol network-coated ZIF-8 synergistically modified collagen fiber-based aerogel.

[0005] The first technical solution adopted in this invention is a method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network, comprising the following steps: Step 1: Prepare the metal-organic framework compound ZIF-8; Step 2: Prepare ZIF-8@TA dispersion based on the product obtained in Step 1; Step 3: Prepare ZIF-8@MPN dispersion based on the product obtained in Step 2, then wash and dry it; Step 4: Prepare the Col / CNF composite dispersion; Step 5: Prepare a Col / CNF-ZIF-8@MPN composite dispersion based on the products obtained in Steps 3 and 4; Step 6: Prepare Col / CNF-ZIF-8@MPN composite aerogel based on the product obtained in Step 5.

[0006] The first technical solution of this invention is further characterized by: The specific process of step 1 is as follows: Zinc salt and 2-methylimidazole were dissolved in methanol, respectively. After mixing, the mixture was magnetically stirred at room temperature for 24-36 h. The mixture was washed by alternating centrifugation with deionized water and methanol, respectively, and dried at 40-80 °C to obtain the metal-organic framework compound ZIF-8.

[0007] In step 1, the molar ratio of zinc salt to 2-methylimidazole is 1:4~36.

[0008] In step 1, the zinc salt is either zinc nitrate or zinc acetate.

[0009] The specific process of step 2 is as follows: the metal-organic framework compound ZIF-8 obtained in step 1 is ultrasonically dispersed in water to form a dispersion of 0.5~1.5 mg / mL. The dispersion is then added to a tannic acid solution of 2.5~10 mg / mL and stirred at room temperature for 10~30 min to form a ZIF-8@TA dispersion.

[0010] The specific process of step 3 is as follows: 10~30 mg / L of metal salt solution is added dropwise to the ZIF-8@TA dispersion, and the mixture is stirred at room temperature to obtain the ZIF-8@MPN dispersion. The mixture is then washed by cross-centrifugation with water and methanol, dried and ground to obtain ZIF-8@MPN powder.

[0011] In step 3, the metal salt solution is one of magnesium chloride solution, copper sulfate solution, or ferric chloride solution. The specific process of step 4 is as follows: Collagen is dissolved in acetic acid solution and stirred at room temperature for 2-4 hours to form a 6-10 mg / mL collagen solution. Then, cellulose nanofibers are ultrasonically dispersed in water for 30-60 minutes to obtain a 6-10 mg / mL cellulose nanofiber dispersion. Finally, the cellulose nanofiber dispersion is added dropwise to the collagen solution, and stirred at room temperature for 4-8 hours to form a uniformly dispersed Col / CNF composite dispersion.

[0012] In step 4, the cellulose nanofibers have a diameter of 10-30 nm and a length of 300-600 nm, and the collagen solution concentration is 5 g / mL-10 g / mL; the mass ratio of collagen to cellulose nanofibers is 1:0.5-2; the collagen is obtained by enzymatic hydrolysis of bovine Achilles tendon.

[0013] The second technical solution adopted in this invention is a metal-polyphenol network-coated ZIF-8 synergistically modified collagen fiber-based aerogel, which is prepared by the above-mentioned preparation method of metal-polyphenol network-coated ZIF-8 synergistically modified collagen fiber-based aerogel.

[0014] The beneficial effects of this invention are as follows: 1) The manufacturing method of this invention is simple and easy to implement, and the resulting aerogel has good biocompatibility; 2) The introduction of ZIF-8@MPN in this invention not only enhances the cross-linking degree of collagen-cellulose nanofibers, but also increases the porosity and antibacterial properties of the aerogel.

[0015] 3) By using MPN-modified ZIF-8 nanocomposite particles and cellulose nanofibers to further crosslink and enhance the collagen network, a collagen fiber-based composite aerogel with high strength and antibacterial properties was prepared. Attached Figure Description

[0016] Figure 1(a) shows the XRD patterns of ZIF-8 and ZIF-8@TA powders prepared in Example 2 of the preparation method of ZIF-8 synergistic modification of collagen fiber-based aerogel by metal-polyphenol network package of the present invention. Figure 1(b) shows the FTIR spectra of ZIF-8 and ZIF-8@TA powders prepared in Example 2 of the preparation method of ZIF-8 synergistic modification of collagen fiber-based aerogel by metal-polyphenol network package of the present invention. Figure 2 Example 2 shows the SEM image of the Col / CNF-ZIF-8@MPN composite aerogel prepared according to the preparation method of the metal-polyphenol network package ZIF-8 synergistic modification of collagen fiber-based aerogel of the present invention.

[0017] Figure 3 Example 2 shows a photograph of the hemostatic application of the Col / CNF-ZIF-8@MPN composite aerogel prepared by the preparation method of the metal-polyphenol network package ZIF-8 synergistic modified collagen fiber-based aerogel of the present invention. Detailed Implementation

[0018] The following detailed description is provided in conjunction with specific implementation methods.

[0019] The preparation method of ZIF-8 synergistically modified collagen fiber-based aerogel using a metal-polyphenol network according to the present invention specifically includes the following steps: Step 1: Dissolve zinc salt and 2-methylimidazole separately in 50 mL of methanol, mix and stir magnetically at room temperature for 24-36 h, wash twice by alternating centrifugation with deionized water and methanol, and dry at 40-80 °C to obtain metal-organic framework compound ZIF-8; wherein the molar ratio of zinc salt to 2-methylimidazole is 1:4-36. Step 2: The metal-organic framework compound ZIF-8 obtained in Step 1 is ultrasonically dispersed in water to form a dispersion of 0.5~1.5 mg / mL. The dispersion is then added to a tannic acid (TA) solution of 2.5~10 mg / mL and stirred at room temperature for 10~30 min to form a ZIF-8@TA dispersion. Step 3: Add 10~30 mg / L of metal salt (Mg) dropwise to the ZIF-8@TA dispersion. 2+ Cu 2+ Fe 3+） The solution was stirred at room temperature for 1 hour to obtain a ZIF-8@MPN dispersion. The dispersion was washed twice by cross-centrifugation with water and methanol, and then dried and ground at 40°C to obtain ZIF-8@MPN powder for later use. Step 4: Dissolve collagen (Col) in 5 mL of 0.5 mol / L acetic acid solution and stir at room temperature for 2–4 h to form a 6–10 mg / mL collagen solution. Then, ultrasonically disperse cellulose nanofibers (CNF) in water for 30–60 min to obtain a 6–10 mg / mL CNF dispersion. Finally, add the CNF dispersion dropwise to the Col solution and stir at room temperature for 4–8 h to form a uniformly dispersed Col / CNF composite dispersion. The cellulose nanofibers have a diameter of 10–30 nm and a length of 300–600 nm. The Col solution concentration is 5 g / mL–10 g / mL. The mass ratio of Col to CNF is 1:0.5–2. The collagen is obtained by enzymatic hydrolysis of bovine Achilles tendon. Step 5: Disperse ZIF-8@MPN in water using ultrasonication to form a dispersion of 0.5~1.5 mg / mL. Add the dispersion dropwise to the Col / CNF composite dispersion under stirring. Stir at room temperature for 30~60 min to form a uniform Col / CNF-ZIF-8@MPN composite dispersion. The mass ratio of ZIF-8@MPN to Col is 1:5~20, preferably 1:10. Step 6: Subsequently, the Col / CNF-ZIF-8@MPN composite dispersion was transferred to a mold, and finally freeze-dried at -72℃ for 48 h to obtain the Col / CNF-ZIF-8@MPN composite aerogel.

[0020] The mold is a polytetrafluoroethylene mold with a copper sheet base, which is placed in liquid nitrogen for directional crystallization; Example 1 First, MPN-modified ZIF-8 composite nanoparticles were prepared: 0.583 g of zinc nitrate hexahydrate and 0.670 g of 2-methylimidazole powder were weighed and dissolved in 50 mL of methanol respectively. After ultrasonic dispersion, the mixture was stirred continuously at room temperature for 24 h to allow for complete reaction. The nanoparticles were washed twice with water and methanol respectively, and dried at 40 °C to obtain white ZIF-8 powder. 10 mg of ZIF-8 powder was ultrasonically dispersed in 10 mL of deionized water for 15 min to obtain a 1 mg / mL ZIF-8 dispersion. This dispersion was added dropwise to 50 mL of a prepared 2.5 mg / mL tannic acid solution and reacted at room temperature for 10 min to obtain a ZIF-8@TA dispersion. Then, 10 mL of a 1 mg / mL hexahydrate and magnesium chloride solution was added dropwise to the dispersion. After reacting for 30 min, the mixture was centrifuged, washed twice with water and methanol respectively, and dried at 40 °C to obtain yellow-green ZIF-8@MPN powder.

[0021] Next, 50 mg of collagen was dissolved in 5 mL of 0.5 mol / L acetic acid solution (pH 2.5) by stirring for 2 hours. 25 mg of cellulose nanofibers (CNF) were ultrasonically dispersed in 5 mL of water for 15 minutes. Then, the CNF dispersion was added dropwise to the Col solution while stirring, and the mixture was stirred for 30 minutes to ensure uniform dispersion. Afterwards, 5 mg of ZIF-8@MPN (Mg...) was added... 2+ The powder was ultrasonically treated in 10 mL of water for 15 min, then added dropwise to a CNF / Col dispersion and stirred for 30 min to obtain a Col / CNF-ZIF-8@MPN composite dispersion. Finally, the dispersion was transferred to a polytetrafluoroethylene container with a copper base, directionally frozen in liquid nitrogen (77 K), and freeze-dried at -72 °C for 48 h to obtain an antibacterial collagen aerogel with mechanical strength.

[0022] Example 2 First, MPN-modified ZIF-8 composite nanoparticles were prepared: 0.583 g of zinc nitrate hexahydrate and 1.13 g of 2-methylimidazole powder were weighed and dissolved in 50 mL of methanol, respectively. After ultrasonic dispersion, the mixture was stirred continuously at room temperature for 24 h to allow for complete reaction. The nanoparticles were washed twice with water and methanol, respectively, and dried at 40 °C to obtain white ZIF-8 powder. 10 mg of ZIF-8 powder was ultrasonically dispersed in 10 mL of deionized water for 15 min to obtain a 1 mg / mL ZIF-8 dispersion. This dispersion was added to 50 mL of a prepared 3 mg / mL tannic acid solution and reacted at room temperature for 15 min to obtain a ZIF-8@TA dispersion. Then, 10 mL of a 3 mg / mL hexahydrate and magnesium chloride solution was added dropwise to the dispersion. After reacting for 30 min, the mixture was centrifuged, washed twice with water and methanol, respectively, and dried at 40 °C to obtain yellow-green ZIF-8@MPN powder.

[0023] Next, 50 mg of collagen was dissolved in 5 mL of 0.5 mol / L acetic acid solution (pH 2.5) by stirring for 2 hours. 40 mg of cellulose nanofibers (CNF) were ultrasonically dispersed in 5 mL of water for 15 minutes. Then, the CNF dispersion was added dropwise to the Col solution while stirring, and the mixture was stirred for 30 minutes to ensure uniform dispersion. Afterwards, 5 mg of ZIF-8@MPN (Mg...) was added... 2+ The powder was ultrasonically treated in 10 mL of water for 15 min, then added dropwise to a CNF / Col dispersion and stirred for 30 min to obtain a Col / CNF-ZIF-8@MPN composite dispersion. Finally, the dispersion was transferred to a polytetrafluoroethylene container with a copper base, directionally frozen in liquid nitrogen (77 K), and freeze-dried at -72 °C for 48 h to obtain an antibacterial collagen aerogel with mechanical strength.

[0024] The X-ray diffraction (XRD) patterns of the samples (Figure 1(a)) show that the diffraction peak positions of the TA-modified ZIF-8 particles are completely consistent with those of the original ZIF-8, and there are no obvious impurity peaks. This indicates that the TA loading did not destroy the highly ordered crystal structure of ZIF-8 itself, laying the foundation for its structural stability in the composite material. As shown in Figure 1(b), Fourier transform infrared spectroscopy (FT-IR) analysis further provides evidence of the surface chemical composition: characteristic absorption peaks attributable to tannic acid, such as 1688 cm⁻¹, can be observed in the ZIF-8@TA spectrum. -1 The C=O stretching vibration peak at 1547 cm⁻¹ and the peak at 1547 cm⁻¹ -1 The aromatic ring skeletal vibration peak is also visible at 3134 cm⁻¹. -1 and 2933 cm -1 The imidazole ring CH stretching vibration peak at the position clearly confirms that the TA molecule has been successfully loaded onto the ZIF-8 surface and coordinated with metal ions to form a metal-polyphenol network (MPN). Scanning electron microscopy (SEM) images (e.g.) Figure 2 The image visually demonstrates the microporous structure of the final composite aerogel. Cellulose nanofibers (CNF) and collagen fibers are interwoven, forming a continuous and stable three-dimensional network framework, while ZIF-8@MPN nanoparticles are uniformly dispersed and embedded within this biopolymer matrix. This unique porous structure provides the material with excellent specific surface area and pore channels, significantly enhancing the mechanical properties of the entire network. The sample underwent a hemostasis experiment on mouse liver (…). Figure 3The results showed that the bleeding in the experimental group using the sample was significantly less than that in the control group not using the sample. In summary, XRD and FT-IR results jointly confirmed the preparation of ZIF-8@MPN, while SEM images revealed the robust porous structure formed after successful composite with the biopolymer. This structure provides crucial microscopic evidence for the material's subsequent excellent mechanical strength and antibacterial function, and hemostasis experiments demonstrated that the sample has good hemostatic effects.

[0025] Example 3 First, MPN-modified ZIF-8 composite nanoparticles were prepared: 0.583 g of zinc nitrate hexahydrate and 2.01 g of 2-methylimidazole powder were weighed and dissolved in 50 mL of methanol, respectively. After ultrasonic dispersion, the mixture was stirred continuously at room temperature for 24 h to allow for complete reaction. The nanoparticles were washed twice with water and methanol, respectively, and dried at 40 °C to obtain white ZIF-8 powder. 10 mg of ZIF-8 powder was ultrasonically dispersed in 10 mL of deionized water for 15 min to obtain a 1 mg / mL ZIF-8 dispersion. This dispersion was added to 50 mL of a prepared 4 mg / mL tannic acid solution and stirred at room temperature for 15 min to obtain a ZIF-8@TA dispersion. Then, 10 mL of a 5 mg / mL copper chloride hexahydrate solution was added dropwise to the dispersion. After reacting for 30 min, the mixture was centrifuged, washed twice with water and methanol, respectively, and dried at 40 °C to obtain light blue ZIF-8@MPN powder.

[0026] Next, 50 mg of collagen was dissolved in 5 mL of 0.5 mol / L acetic acid solution (pH 2.5) by stirring for 2 hours. 55 mg of cellulose nanofibers (CNF) were ultrasonically dispersed in 5 mL of water for 15 minutes. Then, the CNF dispersion was added dropwise to the Col solution while stirring, and the mixture was stirred for 30 minutes to ensure uniform dispersion. Afterwards, 5 mg of ZIF-8@MPN (Cu 2+ The powder was ultrasonically treated in 10 mL of water for 15 min, then added dropwise to a CNF / Col dispersion and stirred for 30 min to obtain a Col / CNF-ZIF-8@MPN composite dispersion. Finally, the dispersion was transferred to a polytetrafluoroethylene container with a copper base, directionally frozen in liquid nitrogen (77 K), and freeze-dried at -72 °C for 48 h to obtain a collagen aerogel with mechanical strength.

[0027] Example 4 First, MPN-modified ZIF-8 composite nanoparticles were prepared: 0.583 g of zinc nitrate hexahydrate and 2.68 g of 2-methylimidazole powder were weighed and dissolved in 50 mL of methanol, respectively. After ultrasonic dispersion, the mixture was stirred continuously at room temperature for 24 h to allow for complete reaction. The nanoparticles were washed twice with water and methanol, respectively, and dried at 40 °C to obtain white ZIF-8 powder. 10 mg of ZIF-8 powder was ultrasonically dispersed in 10 mL of deionized water for 15 min to obtain a 1 mg / mL ZIF-8 dispersion. This dispersion was added to 50 mL of a prepared 6 mg / mL tannic acid solution and stirred at room temperature for 20 min to obtain a ZIF-8@TA dispersion. Then, 10 mL of a 7 mg / mL copper chloride hexahydrate solution was added dropwise to the dispersion. After reacting for 30 min, the mixture was centrifuged, washed twice with water and methanol, respectively, and dried at 40 °C to obtain light blue ZIF-8@MPN powder.

[0028] Next, 50 mg of collagen was dissolved in 5 mL of 0.5 mol / L acetic acid solution (pH 2.5) by stirring for 2 hours. 70 mg of cellulose nanofibers (CNF) were ultrasonically dispersed in 5 mL of water for 15 minutes. Then, the CNF dispersion was added dropwise to the Col solution while stirring, and the mixture was stirred for 30 minutes to ensure uniform dispersion. Afterwards, 10 mg of ZIF-8@MPN (Cu 2+ The powder was ultrasonically treated in 10 mL of water for 15 min, then added dropwise to a CNF / Col dispersion and stirred for 30 min to obtain a Col / CNF-ZIF-8@MPN composite dispersion. Finally, the dispersion was transferred to a polytetrafluoroethylene container with a copper base, directionally frozen in liquid nitrogen (77 K), and freeze-dried at -72 °C for 48 h to obtain a collagen aerogel with mechanical strength.

[0029] Example 5 First, MPN-modified ZIF-8 composite nanoparticles were prepared: 0.583 g of zinc nitrate hexahydrate and 3.35 g of 2-methylimidazole powder were weighed and dissolved in 50 mL of methanol respectively. After ultrasonic dispersion, the mixture was stirred continuously at room temperature for 24 h to allow for complete reaction. The nanoparticles were washed twice with water and methanol respectively, and dried at 40 °C to obtain white ZIF-8 powder. 10 mg of ZIF-8 powder was ultrasonically dispersed in 10 mL of deionized water for 15 min to obtain a 1 mg / mL ZIF-8 dispersion. This dispersion was added to 50 mL of a prepared 8 mg / mL tannic acid solution and stirred at room temperature for 25 min to obtain a ZIF-8@TA dispersion. Then, 10 mL of a 9 mg / mL copper chloride hexahydrate solution was added dropwise to the dispersion. After reacting for 30 min, the mixture was centrifuged, washed twice with water and methanol respectively, and dried at 40 °C to obtain light blue ZIF-8@MPN powder.

[0030] Next, 50 mg of collagen was dissolved in 5 mL of 0.5 mol / L acetic acid solution (pH 2.5) by stirring for 2 hours. 85 mg of cellulose nanofibers (CNF) were ultrasonically dispersed in 5 mL of water for 15 minutes. Then, the CNF dispersion was added dropwise to the Col solution while stirring, and the mixture was stirred for 30 minutes to ensure uniform dispersion. Afterwards, 10 mg of ZIF-8@MPN (Cu 2+ The powder was ultrasonically treated in 10 mL of water for 15 min, then added dropwise to a CNF / Col dispersion and stirred for 30 min to obtain a Col / CNF-ZIF-8@MPN composite dispersion. Finally, the dispersion was transferred to a polytetrafluoroethylene container with a copper base, directionally frozen in liquid nitrogen (77 K), and freeze-dried at -72 °C for 48 h to obtain a collagen aerogel with mechanical strength.

[0031] Example 6 First, MPN-modified ZIF-8 composite nanoparticles were prepared: 0.583 g of zinc nitrate hexahydrate and 4.52 g of 2-methylimidazole powder were weighed and dissolved in 50 mL of methanol, respectively. After ultrasonic dispersion, the mixture was stirred continuously at room temperature for 24 h to allow for complete reaction. The nanoparticles were washed twice with water and methanol, respectively, and dried at 40 °C to obtain white ZIF-8 powder. 10 mg of ZIF-8 powder was ultrasonically dispersed in 10 mL of deionized water for 15 min to obtain a 1 mg / mL ZIF-8 dispersion. This dispersion was added to 50 mL of a prepared 10 mg / mL tannic acid solution and stirred at room temperature for 30 min to obtain a ZIF-8@TA dispersion. Then, 10 mL of a 10 mg / mL copper chloride hexahydrate solution was added dropwise to the dispersion. After reacting for 30 min, the mixture was centrifuged, washed twice with water and methanol, respectively, and dried at 40 °C to obtain light blue ZIF-8@MPN powder.

[0032] Next, 50 mg of collagen was dissolved in 5 mL of 0.5 mol / L acetic acid solution (pH 2.5) by stirring for 2 hours. 100 mg of cellulose nanofibers (CNF) was ultrasonically dispersed in 5 mL of water for 15 minutes. Then, the CNF dispersion was added dropwise to the Col solution while stirring, and the mixture was stirred for 30 minutes to ensure uniform dispersion. Afterwards, 10 mg of ZIF-8@MPN (Cu 2+ The powder was ultrasonically treated in 10 mL of water for 15 min, then added dropwise to a CNF / Col dispersion and stirred for 30 min to obtain a Col / CNF-ZIF-8@MPN composite dispersion. Finally, the dispersion was transferred to a polytetrafluoroethylene container with a copper base, directionally frozen in liquid nitrogen (77 K), and freeze-dried at -72 °C for 48 h to obtain a collagen aerogel with mechanical strength.

[0033] This invention provides a method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network. The method includes extracting collagen from bovine Achilles tendon using an enzymatic method, preparing ZIF-8 nanoparticles using a hydrothermal method, surface-modifying ZIF-8 with TA, introducing metal ions to form ZIF-8@MPN, then dropwise adding a dispersion of the composite nanoparticles to a collagen-cellulose nanofiber solution, adjusting the pH of the dispersion, gelling at room temperature, and finally obtaining the collagen composite aerogel through directional freeze-drying. This method achieves the modification of ZIF-8 nanoparticles with MPN, forming a coating layer on their surface, increasing the surface chemical activity and stability of the nanoparticles, promoting further cross-linking with the cellulose nanofiber-collagen network, and preparing an antibacterial collagen fiber-based aerogel with mechanical strength, which is expected to be used in biomedical fields such as wound hemostatic materials.

Claims

1. A method for preparing a metal-polyphenol network coated ZIF-8 synergistically modified collagen fiber based aerogel, characterized in that: The method comprises the following steps: Step 1, preparing a metal-organic framework compound ZIF-8; Step 2, preparing a ZIF-8@TA dispersion liquid according to the product obtained in step 1; Step 3, preparing a ZIF-8@MPN dispersion liquid according to the product obtained in step 2, and then washing and drying; Step 4, preparing a Col / CNF composite dispersion liquid; Step 5, preparing a Col / CNF-ZIF-8@MPN composite dispersion liquid according to the products obtained in steps 3 and 4; Step 6, preparing a Col / CNF-ZIF-8@MPN composite aerogel according to the product obtained in step 5.

2. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 1, characterized in that: The specific process of step 1 is as follows: The zinc salt and 2-methyl imidazole are respectively dissolved in methanol, mixed, magnetically stirred at room temperature for 24-36 h, cross-centrifugally washed with deionized water and methanol, and dried at 40-80 ℃ to obtain the metal-organic framework compound ZIF-8.

3. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 2, characterized in that: In step 1, the molar ratio of the zinc salt to 2-methyl imidazole is 1:4-36.

4. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 2, characterized in that: In step 1, the zinc salt is one of zinc nitrate and zinc acetate.

5. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 2, characterized in that: The specific process of step 2 is as follows: the metal-organic framework compound ZIF-8 obtained in step 1 is ultrasonically dispersed in water to form a 0.5-1.5 mg / mL dispersion liquid, the dispersion liquid is added to a 2.5-10 mg / mL tannic acid solution, and a ZIF-8@TA dispersion liquid is formed after stirring at room temperature for 10-30 min.

6. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 5, characterized in that: The specific process of step 3 is as follows: 10-30 mg / L of a metal salt solution is added dropwise to the ZIF-8@TA dispersion liquid, a ZIF-8@MPN dispersion liquid is obtained after stirring at room temperature, and the ZIF-8@MPN powder is obtained after cross-centrifugally washing with water and methanol and drying and grinding.

7. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 6, characterized in that: In step 3, the metal salt solution is one of a magnesium chloride solution, a copper sulfate solution and a ferric chloride solution.

8. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 7, characterized in that: The specific process of step 4 is as follows: collagen is dissolved in an acetic acid solution, stirred at room temperature for 2-4 h to form a 6-10 mg / mL collagen solution, cellulose nanofibers are ultrasonically dispersed in water for 30-60 min to obtain a 6-10 mg / mL cellulose nanofiber dispersion liquid, and finally the cellulose nanofiber dispersion liquid is added dropwise to the collagen solution, and a uniformly dispersed Col / CNF composite dispersion liquid is formed after stirring at room temperature for 4-8 h.

9. The method for preparing ZIF-8 synergistically modified collagen fiber-based aerogel coated with a metal-polyphenol network according to claim 8, characterized in that: In step 4, the cellulose nanofibers have a diameter of 10-30 nm and a length of 300-600 nm, the concentration of the collagen solution is 5 g / mL-10 g / mL, the mass ratio of collagen to cellulose nanofibers is 1:0.5-2, and the collagen is collagen obtained by enzymatic hydrolysis of bovine Achilles tendon.

10. A metal-polyphenol network coated ZIF-8 synergistically modified collagen fiber-based aerogel is prepared by the method as claimed in any one of claims 1-9.

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