679 results about "Cross-Linking Reagents" patented technology

The invention relates to the technical field of hydrogel, in particular to a preparation method and application of EGCG-mediated hydrogel, a lysozyme solution is heated under the acidic condition to form lysozyme amyloid fibrils LAFs, EGCG is dissolved in a buffer solution and mixed with the LAFs solution obtained in the step 1 in proportion to form an LAFs-EGCG compound, and the EGCG-mediated hydrogel is prepared. The chitosan CS is dissolved in an acetic acid buffer solution, glutaraldehyde is added to serve as a cross-linking agent, the mixture is mixed with the LAFs-EGCG compound obtained in the step 2 and stirred, the composite hydrogel is formed, the concentration of EGCG is 0.2-1.0 wt%, the concentration of LAFs is 5 wt%, the concentration of chitosan is 2 wt%, the pH value of the lysozyme solution in the step 1 is 2.0, the heating temperature is 77 DEG C, the heating time is 10 hours, the concentration of EGCG in the step 2 is 0.4-0.8 wt%, and the pH value of the lysozyme solution in the step 2 is 1.5-2.5. In the step 3, the concentration of glutaraldehyde is 2%, the storage modulus G'of the hydrogel is 325-480 Pa, the hardness is 2176.71 g, and the bacteriostasis rate on staphylococcus aureus and salmonella exceeds 95%.

The invention provides a preparation method of a recombinant collagen dressing, and belongs to the technical field of medical dressings. According to the technical scheme, stacked short sequences and continuous human collagen amino acid short sequences are repeatedly combined for multiple times to form recombinant collagen with specificity, and high similarity of the recombinant collagen with human collagen is ensured. On the basis, 4-FPBA is used as a cross-linking agent to respectively form a Schiff base bond responsive to pH and a boric acid ester bond responsive to glucose with CMCS and two kinds of HA with different molecular weights, and then the double-dynamic covalent cross-linked network adhesive hydrogel is synthesized. The triple-helix structure of the recombinant collagen is combined with a specific receptor on a cell membrane, and cell behaviors are regulated and controlled by inducing signal transduction through a cytoskeleton, so that skin microcirculation can be effectively improved, and a skin barrier can be repaired; the hydrogel dressing matrix has the effects of resisting inflammation, resisting oxidation, resisting bacteria, promoting healing and the like, the biological performance of the dressing is remarkably improved, and a better curative effect is achieved.

The invention relates to the technical field of hydraulic fracturing exploitation of deep / ultra-deep oil and gas reservoirs, and discloses a gel-coated temporary plugging agent and a preparation method and application thereof.The gel-coated temporary plugging agent comprises a proppant inner core and a degradable gel shell coating the outer surface of the proppant inner core; the degradable gel shell is formed by a gel shell gelling solution, the gel shell gelling solution comprises small-molecule comonomers and a degradable cross-linking agent, and the small-molecule comonomers comprise acrylamide, N, N-dimethylformamide, N, N-dimethylformamide, N, N-dimethylformamide, N, N-dimethylformamide, N, N-dimethylformamide, N, N-dimethylformamide the initiator is one or more of N, N-dimethylacrylamide, acrylic acid, hydroxyethyl acrylate, benzyl acrylate, 2-propyl acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and N-vinyl pyrrolidone; and the initiator is one or more of N, N-dimethylacrylamide, acrylic acid, hydroxyethyl acrylate, benzyl acrylate, 2-propyl acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid and N-vinyl pyrrolidone. The gel-coated temporary plugging agent can be used for effectively plugging in a fracturing time period at high temperature / ultrahigh temperature, and the flow conductivity of fractured cracks can be enhanced by exposing an internal propping agent after the gel-coated temporary plugging agent is degraded.

The invention discloses a kind of preparation method of amino hyperbranched siloxane and its modified polyimide aerogel material.First, alkoxysilane X with amino active functional group, alkoxysilane Y of inactive functional group and water are carried out autocatalytic controlled hydrolysis condensation under sub-stoichiometric ratio, obtain multifunctional group (such as other active groups, alkoxyl group, amino) amino hyperbranched siloxane liquid (HPSi NH2) with controllable amino content, then using HPSi NH2 as cross-linking agent and anhydride-terminated polyamic acid solution reaction to obtain functionalized polyamic acid, which is stirred with tertiary amine and deionized water to obtain functionalized polyamic acid wet gel, which is passed through freeze drying, high temperature imidization treatment to obtain amino hyperbranched siloxane modified polyimide aerogel material. This material has excellent flexibility, resilience, heat resistance and flame retardancy, and can be applied to aerospace, communication, catalysis and filtration fields.

The invention discloses an enzyme immobilization method based on charge directed crosslinking, and belongs to the technical field of enzyme immobilization. The method sequentially comprises the following steps: reacting an enzyme with a modifier containing an anionic group to generate an electronegative modified enzyme; dissolving a protonated amino carrier in an acidic buffer solution to form a first solution, and dispersing a dissociation anion group-containing carrier and a modification enzyme in an alkaline buffer solution to form a second solution; mixing the two solutions, and constructing a gel network immobilized enzyme through electrostatic crosslinking; and finally, strengthening the gel network by using a multivalent metal ion solution. Directional anchoring of the enzyme in the gel is achieved through charge matching, the network stability and the enzyme microenvironment are synchronously optimized in combination with metal ion coordination, use of a covalent cross-linking agent is avoided in the whole process, conformation damage of an enzyme active center is avoided, the activity retention rate, the operation half-life period and the substrate mass transfer efficiency of the immobilized enzyme are remarkably improved, and the immobilized enzyme has good application prospects. The method is suitable for efficient immobilization of industrial enzymes such as beta-glucosidase, and has high biocompatibility and industrial potential.

The invention discloses an oral monoclonal antibody micro-coated nanopolysaccharide microsphere preparation for targeted therapy of inflammatory bowel diseases and a preparation method thereof. According to the method, oxidized mannan and an anti-TNF-alpha monoclonal antibody are mixed and cross-linked by a cross-linking agent containing a diselenide bond to form the drug-loaded nanoparticles. Mixing the drug-loaded nanoparticles with pectin, dropwise adding the mixture into a calcium chloride solution through an electrostatic spinning device, and carrying out ionic crosslinking to obtain the oral monoclonal antibody micro-coated nano polysaccharide microsphere preparation with the particle size range of 180-200 microns. The drug-loaded polysaccharide microsphere delivers the wrapped drug-loaded nanoparticles to a colitis disease part through electrostatic interaction. The drug-loaded nanoparticles are targeted to macrophages, release of the monoclonal antibody is accelerated under the triggering of high-concentration active oxygen at an inflammation part, and the oral stability and the treatment effect of the monoclonal antibody drug are improved. The polysaccharide is used as a monoclonal antibody targeted delivery carrier, raw materials are cheap and easy to obtain, the preparation process is simple and convenient, reaction conditions are mild, and application and development are easy.

The invention discloses a recombinant III-type human collagen composition. The recombinant III-type human collagen composition comprises recombinant III-type human collagen, a first buffer solution and a stabilizer, the stabilizer is selected from at least one of glycerol, butanediol, pentanediol, mannitol and trehalose. According to the recombinant III type human collagen composition, a chemical cross-linking agent or an enzymatic promoter is not added for cross-linking, and the used reagents are free of cytotoxicity, sensitization and other safety risks. Therefore, the recombinant III-type human collagen composition has no crosslinking agent residue, can form a three-dimensional network structure, can avoid the problem that the recombinant III-type human collagen and the polysaccharide are compounded to generate precipitates, also has good biocompatibility, degradability and high stability, especially has relatively high thermal stability, and can be used for preparing the recombinant III-type human collagen composition. The wound healing and repairing can be promoted, the healthy skin ecology can be reconstructed, and a new choice is provided for a biomedical material.

The invention relates to the technical field of adhesives, and provides a wet state maintaining type vegetable protein adhesive as well as a preparation method and application thereof. The hyperbranched catechol polymer adhesive filler disclosed by the invention is prepared by carrying out ring-opening reaction on epoxy groups of neopentyl glycol diglycidyl ether and pentaerythritol tetraglycidyl ether and amino groups of dopamine hydrochloride. Meanwhile, the vegetable protein adhesive is prepared from vegetable protein, a cross-linking agent and the adhesive filler according to a certain proportion. According to the adhesive filler and the corresponding vegetable protein adhesive, the defect that in the prior art, a bio-based adhesive, especially a vegetable protein adhesive, is poor in product performance due to poor moisture retention can be overcome.

The invention discloses starch-collagen composite hydrogel as well as a preparation method and application thereof. Collagen is catalyzed by microbial transglutaminase to form a covalent cross-linked network, and meanwhile, hydroxypropyl starch is introduced to construct a physical interpenetrating network through molecular chain penetration and hydrogen-bond interaction; and chondroitin sulfate is further integrated to strengthen the network structure and biological activity through electrostatic interaction. The method is mild in condition and does not need a toxic chemical cross-linking agent, the obtained composite hydrogel has an interpenetrating double-network structure and has excellent mechanical properties, enzymatic degradation resistance and cell affinity, the compression modulus of the composite hydrogel is remarkably improved, the composite hydrogel can keep structural stability for a long time in a collagenase environment, cell adhesion and proliferation can be effectively promoted, and the composite hydrogel has a good application prospect. The hydrogel can be widely applied to tissue engineering scaffolds, wound dressings, drug sustained-release carriers and cartilage repair materials.

The present invention belongs to the technical field of waterborne polyurethane, and specifically relates to a method for synthesizing an internally cross-linked cationic waterborne polyurethane emulsion. The method comprises the following steps: 1) reacting glycidol and diethanolamine until the infrared spectrum analysis shows that the glycidol and diethanolamine are at 908 cm ‑1 and 845cm ‑1 The epoxy groups disappear, the reaction is stopped, and the product EDEOA, a tertiary amino crosslinking agent, is obtained as a light yellow viscous liquid; 2) polyol and diisocyanate are added to a reactor and heated and kept warm under stirring for reaction; 3) solvent, tertiary amino crosslinking agent, tertiary amino small molecule alcohol amine chain extender, solvent and catalyst are then added to react to obtain a polyurethane intermediate; 4) a neutralizing agent is then added to the reaction system for neutralization reaction, and the temperature is lowered after the reaction is completed; 5) water is added to quickly disperse the mixture uniformly, and the solvent is removed in vacuo to obtain a waterborne polyurethane emulsion. The present invention mainly solves the technical problems existing in the synthesis of cationic waterborne polyurethanes, such as poor emulsion stability, low film mechanical properties, and poor water and solvent resistance.

The invention relates to the technical field of cleaning agents, and discloses a biodegradable environment-friendly cleaning agent, which comprises: a composite surfactant system comprising at least one nonionic surfactant, an ampholytic surfactant and a chelating functional surfactant; the plant extract oil system comprises limonene and a eucalyptus oil mixture; the functional particle system comprises nanoscale enzyme microcapsules and slow-release type oxidized particles; the natural polysaccharide stable network system comprises at least two polysaccharide thickeners and a bio-based cross-linking agent, and the assistant system comprises a metal ion chelating agent, a buffer acid system and water. By introducing sodium polyaspartate as a green chelating surfactant, efficient chelating of calcium and magnesium ions under a hard water condition is realized, the cleaning power is remarkably improved, water stain residues are reduced, and the cleaning performance with wider adaptability is obtained.

The invention relates to the technical field of fertilizers and pesticides for agricultural production, and discloses a liquid pesticide fertilizer for preventing and treating root-knot nematodes in a water-fertilizer integrated system and application thereof, and the liquid pesticide fertilizer is prepared from the following components: a plant source nematicide, a biocontrol inoculant, a macroelement and medium trace element fertilizer, a boron cross-linking agent, a modified polycarboxylic acid dispersing agent, a microbial protective agent and the like. The preparation method comprises the steps of biological phase pretreatment, matrix phase construction, oil phase micro-emulsification, multiphase fusion and dynamic crosslinking. Through trehalose gradient permeation pretreatment, the survival rate of biocontrol bacteria in a high-salt matrix is increased; a boric acid ester bond dynamic cross-linked network is constructed by using a variable pH adjusting process, so that the system is endowed with shear thinning characteristics, and the contradiction between suspension stability and drip irrigation fluidity is solved; and the chelating dispersion effect of the modified polycarboxylic acid dispersing agent is matched, so that the generation of precipitates is effectively inhibited, and stable coexistence and synergistic interaction of the pesticide, the fertilizer and the bacteria are realized.

The invention discloses a capsule medicament for endoscopic treatment of ulcerative colitis and a preparation method thereof, and belongs to the technical field of biological medicine, the capsule medicament is composed of a capsule matrix and a drug matrix; by adopting a dual control mechanism of an enteric layer coating and a pH response layer coating, accurate release of a medicine at a colon diseased region is ensured, medicine waste of the stomach and the small intestine is reduced, the medicine concentration at a focus is improved, mesalazine or budesonide is combined with the composite composition for treatment, inflammatory response is rapidly inhibited, acute symptoms are controlled, and the curative effect is good. A multi-mechanism synergistic treatment mode is adopted, the anti-inflammatory and repairing effects are enhanced, the clinical remission rate and the mucous membrane healing rate are remarkably improved, the pH response layer is dissolved in a colon alkaline environment, and the MMP-9 peptide cross-linking agent is subjected to enzymolysis at an inflammation part, so that the medicine is continuously released at a focus, the administration frequency is reduced, the compliance of a patient is improved, and the curative effect is good. In addition, the spherical gel particles in the medicament can prevent the medicament from being disintegrated too early in the intestinal tract, and the long-acting effect can be maintained.

A treatment composition that includes a treatment adjunct and a population of core / shell delivery particles, where the shell is made from an acid-treated chitosan and a cross-linking agent, where the acid-treated chitosan results from treating chitosan with a weak acid, or even a mixture of a strong acid and a weak acid. Related methods of making and using such compositions.

The invention belongs to the technical field of gel dressings, and particularly relates to a bio-based gel dressing for wound treatment and a preparation method thereof.The bio-based gel dressing is prepared from, by weight, 10-17 parts of mussel mucin, 13-20 parts of silk fibroin, 1-5 parts of plant vesicles, 2-4 parts of traditional Chinese medicine polysaccharide, 0.05 part of antibacterial peptide, 1.5 parts of glycerinum and 0.3 part of cross-linking agent; nano plant vesicles which are extracted from a traditional Chinese medicine prescription and have the effect of promoting wound healing are used as a carrier for encapsulating antibacterial peptide, and then the antibacterial peptide is encapsulated in a three-dimensional gel network formed by natural protein, so that controlled release and slow release of antibacterial and anti-inflammatory components are realized, and efficient wound healing is promoted.

The invention discloses a preparation method of PBA nanoparticle in-situ modified halloysite nanotube-polyethyleneimine cross-linked composite aerogel, which comprises the following steps: modifying halloysite nanotubes by using an epoxy silane coupling agent to obtain epoxidized HNTs, and further grafting ethylenediamine on the surfaces of the epoxidized HNTs to obtain HNTs rich in amino groups and hydroxyl groups; the preparation method comprises the following steps: respectively stirring and dissolving K4Fe (CN) 6.3 H2O and polyvinylpyrrolidone in a hydrogen chloride solution, then adding HNTs rich in amino groups and hydroxyl groups, ultrasonically dispersing uniformly, and reacting to obtain PBA-coated HNTs; the preparation method comprises the following steps: taking polyethyleneimine as a raw material, taking 1, 3-dichloropropanol as a cross-linking agent, adding an acid-binding agent, carrying out a cross-linking reaction on the polyethyleneimine and PBAatHNTs, finally freeze-drying a reaction solution, then removing the residual acid-binding agent and salts thereof by soaking and cleaning, and drying again to obtain a finished product of aerogel. According to the invention, the problems that polyethyleneimine is easy to remain in a solution and a nano-powder material is not easy to recover and reuse are solved, and the adsorption performance on heavy metal ions is improved.

The invention is applicable to the technical field of biomedicine, and provides dipeptide-photosensitizer molecule co-assembled nanoparticles as well as a preparation method and application thereof. According to the invention, cationic diphenylalanine (CDP) and a biological cross-linking agent genipin are self-assembled to form a dipeptide carrier, and then the dipeptide carrier and a photosensitizer molecule chlorin e6 (Ce6) are co-assembled, so that nanoparticles with controllable size, controllable drug loading capacity and good biocompatibility are successfully prepared. The preparation method is simple and easy to implement, effectively solves the key problems that the traditional photosensitizer molecule Ce6 is poor in biocompatibility and easy to gather, not only can efficiently deliver Ce6, but also obviously improves the application safety and biocompatibility of Ce6. The Ce6 is almost free of dark toxicity under a dark condition, can play a strong photodynamic killing role under illumination, and greatly improves the possibility and application potential of the Ce6 in tumor photodynamic therapy by virtue of the flexible regulation and control advantages of the size and the drug loading capacity.

The invention discloses potato starch nano-carrier immobilized lipase and a preparation method thereof, and relates to the technical field of biological catalysis. The immobilized lipase comprises a lipase and a carrier, and the lipase is immobilized on the carrier; the carrier is potato starch modified magnetic nanoparticles. The immobilized lipase provided by the invention takes the magnetic potato starch nanoparticles as a carrier and has the advantages of being green and environment-friendly and easily available in materials, and the lipase is successfully immobilized on the magnetic nanoparticles by using the potato starch and the traditional glutaraldehyde as cross-linking agents. The method not only improves the activity and stability of the immobilized enzyme, but also has good biocompatibility and safety. By optimizing parameters such as potato starch dosage, enzyme concentration and immobilization time, the obtained immobilized enzyme shows excellent storage stability and repeated utilization rate. In addition, the method provides reference for preparation of other high-performance immobilized enzymes.

The invention discloses high-urease microbial gel, a preparation method and a method for repairing uranium-polluted soil by using the high-urease microbial gel, and belongs to the technical field of environmental pollution microbial treatment. The preparation method comprises the following steps: 1) mixing sodium alginate, urea and a water-retaining agent to obtain a carrier solution; 2) uniformly mixing the high urease bacteria solution in the logarithmic phase with the carrier solution according to a volume ratio of 5-25% to obtain a bacteria solution mixture; and (3) dropwise adding the bacterial liquid mixture into a cross-linking agent which is stirred at a constant speed for cross-linking and curing, and freeze-drying to obtain the high-urease microbial gel. The high-urease microbial gel is applied to the periphery of a root system of a uranium-enriched plant planted in uranium-contaminated soil to be repaired, and uranium-contaminated soil is repaired through combination of microorganisms and plants. Urease-producing bacteria in the high-urease microbial gel induce decomposition of urea to generate carbonate, uranyl ions in the soil are activated, the mobility of uranium in the soil is improved, and extraction of uranium in the soil by uranium-enriched plants is promoted.

The invention relates to the technical field of chitosan, and discloses a preparation method and application of a functional water-absorbing chitosan material, an aldehyde triazine quaternary ammonium salt cross-linking agent and amino of chitosan are subjected to a cross-linking reaction, hydrophilic quaternary ammonium salt and sulfonic acid are grafted into the chitosan material, and the hydrophilicity of chitosan is remarkably improved. And the aldehyde triazine quaternary ammonium salt cross-linking agent contains three aldehyde groups, and forms a porous structure of a space cross-linked network with the chitosan, so that the water absorption rate is greatly increased. The chitosan material contains functional quaternary ammonium salt cation groups which can form electrostatic interaction with Cr2O7 < 2-> anions, meanwhile, nitrogen atoms in sulfonic acid groups, nitrogen-rich triazine and imidazole structures can generate coordination chelation with metal ions such as Cu < 2 + >, and the equilibrium adsorption capacity of the chitosan material to Cu < 2 + > is improved. The method has a wide application prospect in the field of metal-containing sewage treatment.

The invention provides a thermal response hydrogel construction method based on solid-liquid interface repulsive force and water content, which comprises the following steps: establishing a coarse graining model of a thermal response polymer network and a water molecule system, and constructing a three-dimensional polymer gel network by adjusting the number of polymer chain monomers and the proportion of a cross-linking agent; constructing a simulation box according to the network geometric dimension and filling the simulation box with water beads; defining interaction parameters among beads under the dissipative particle dynamics model, performing molecular dynamics simulation, counting the mass center of a polymer skeleton and the number of water beads adjacent to an interface, and calculating the equilibrium moisture content; establishing a solid-liquid interface model, and calculating an equilibrium distance and interaction energy between a water bead plane and a polymer skeleton plane at the adsorption temperature; the network polymerization degree is optimized by adjusting the number of polymer chain monomers, and the optimal design of the thermal response desorption performance is achieved. The method provided by the invention is suitable for macroscopic hydrogel structure evaluation, can quickly obtain equilibrium moisture content and interfacial interaction energy, and guides reasonable proportioning and preparation of the hydrogel.

The invention belongs to the technical field of probiotic protection, and discloses a preparation method and application of probiotic-loaded sulfydryl hyaluronic acid-based hydrogel, sulfydryl hyaluronic acid is prepared by taking cysteamine hydrochloride as a substrate, and connection of L-glutamine is further catalyzed through a cross-linking agent, so that the sulfydryl hyaluronic acid-based hydrogel is obtained. The cross-linking agent is a mixture of N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl) carbodiimide or a mixture of N-hydroxysuccinimide and 1-hydroxybenzotriazole (HOBT), and the cross-linking agent is a mixture of N-hydroxysuccinimide and 1-ethyl-(3-dimethylaminopropyl) carbodiimide and 1-hydroxybenzotriazole (HOBT). The hydrogel prepared by the preparation method disclosed by the invention is used as a probiotic carrier, so that the influence of complex gastrointestinal tracts is effectively resisted, the hydrogel accurately reaches an intestinal injury part and is split, and the targeted intestinal controllable release of probiotics is realized; meanwhile, the L-glutamine is introduced and has a synergistic effect with the probiotics to relieve specific intestinal diseases, so that the L-glutamine can be used as a probiotic supplement for the specific intestinal diseases.

The present disclosure relates to a polypeptide construct for targeted delivery of a payload, comprising a natriuretic peptide receptor (NPR-C) ligand. Also provided is a conjugate comprising; a polypeptide construct for targeted delivery of a payload to NPR-C expressing cells. Further provided are compositions comprising the construct or the conjugate, and kits comprising the construct and a crosslinker, and methods and uses of the same.

The invention relates to the technical field of biochemistry, in particular to a specific affinity enrichment and preparation method of a torreya grandis protease hydrolysate ACE inhibitory peptide, which comprises the following steps: step 1, preparing and characterizing magnetic aminated Fe3O4 nanoparticles; step 2, preparing and characterizing the immobilized trypsin; 3, preparing and characterizing the immobilized ACE, and optimizing reaction conditions; step 4, determining the activity of the immobilized ACE; step 5, then preparing and specifically enriching the Chinese torreya antihypertensive peptide; step 6, then, carrying out molecular docking through AutoDock Vina; according to the method, genipin is adopted as a cross-linking agent, magnetic Fe3O4 nanoparticles with the ACE inhibitory peptide specific affinity recognition function are constructed, specific enrichment of the ACE inhibitory peptide from the torreya grandis cake protein hydrolysate is achieved, and specific separation is achieved.

The invention discloses immunoregulation hydrogel based on ginsenoside Rd, a preparation method and application, and relates to the technical field of biomedical materials and hydrogels. The hydrogel is prepared by taking natural polysaccharides modified by phenylboronic acid groups, derivatives of the natural polysaccharides and methacrylic anhydride modified protein biopolymers as biological matrix materials; ginsenoside Rd is used as a bioactive functional component, and polyvinyl alcohol is used as a cross-linking agent; a first dynamic reversible cross-linked network is formed through chemical cross-linking, and is endowed with injectability, self-healing property and glucose responsiveness; ginsenoside Rd is taken as a main raw material and then subjected to addition polymerization reaction under the irradiation of a photoinitiator and light, a second static covalent cross-linked network is formed, mechanical strength and structural stability are given to the system, in addition, ginsenoside Rd is loaded in the system through boric acid ester bonds, and the slow-release effect is achieved. The problems of stability and bioavailability during local application of the Chinese herbal medicine extract are solved, and healing of chronic and serious wounds can be more effectively promoted.

The invention discloses a preparation method of composite hydrogel microparticles triggered by PH (Potential of Hydrogen). According to the method disclosed by the invention, emulsion templates in different forms are constructed, and acetic acid molecules in an oil phase are diffused to enter water-phase liquid drops so as to lower the pH value of a chitosan-alginic acid homogeneous solution, so that chitosan is protonized and is subjected to ionic crosslinking with alginic acid carboxyl; further, the preparation of chitosan-alginic acid composite microspheres, microcapsules and core-shell hydrogel microparticles is realized. The prepared composite hydrogel microparticles show good morphology stability, monodispersity and a certain autofluorescence characteristic. Meanwhile, no organic solvent or harmful cross-linking agent is used for microsphere forming, and the prepared microparticles have good application prospects.

The invention discloses a nanofiber based on a polypeptide derivative and an enzymatic self-assembly method and application of the nanofiber based on the polypeptide derivative, the sequence of the polypeptide derivative is Nap-Gly-Phe-Phe-pTyr-Lys-Trp-Tyr-Gln-Asn-Met-Ile-Arg, and the Gly-Phe-Phe-pTyr is of an L configuration or a D configuration. The self-assembled polypeptide derivative disclosed by the invention contains an alkaline phosphatase restriction enzyme cutting site, and the self-assembled polypeptide derivative is self-assembled at a specific part with high enzyme specificity expression through enzyme catalysis to form nanofibers. The nanofiber hydrogel obtained through enzymatic treatment is carried out under physiological conditions, high temperature or ultraviolet irradiation is not needed, damage of high temperature to bioactive substances is avoided, the nanofiber hydrogel is more suitable for a temperature-sensitive in-vivo environment, toxic chemical cross-linking agents or photoinitiators do not need to be introduced, the cytotoxicity of the material is remarkably reduced, active enzymes or drugs can be embedded in situ, and the nanofiber hydrogel can be used for in-situ treatment. The biological function is maintained.

The invention discloses a functional and recoverable vegetable protein adhesive with high strength and toughness and a preparation method of the functional and recoverable vegetable protein adhesive. The adhesive is prepared from the following components in parts by mass: 30 parts of soybean protein, 4 to 7.5 parts of acrylamide, 0.5 to 4 parts of methacryloyloxyethyl trimethyl ammonium chloride, 1 to 3 parts of a peptide self-assembly cross-linking agent, 1.6 parts of ammonium persulfate, 5 parts of a metal-polyphenol catalyst and 65 parts of a dispersion medium. The preparation method comprises the following steps: weighing the components in proportion, dispersing the acrylamide, the methacryloyloxyethyl trimethyl ammonium chloride, the peptide self-assembly cross-linking agent and the ammonium persulfate in a medium, uniformly stirring, adding the soybean protein, finally adding the metal-polyphenol catalyst, and uniformly dispersing. The self-assembled amphiphilic peptide fiber is introduced as a dynamic cross-linking agent, and a multi-stage energy dissipation structure is constructed in the adhesive, so that the mechanical strength, the toughness and the function customizability of the adhesive are remarkably improved, and meanwhile, room-temperature polymerizability, recoverability and reprocessing are realized.

The invention relates to collagen microspheres, a preparation method thereof and a filling preparation. The preparation method of the collagen microspheres comprises the following steps: spraying a collagen solution into a macromolecular crowding agent solution, and standing, so that the collagen forms the microspheres; and separating the microspheres from the macromolecular crowding agent solution, and cleaning the microspheres. Wherein the concentration of the macromolecular crowding agent solution is greater than 50mg / mL. According to the method, the collagen microspheres can be prepared without a cross-linking agent. A collagen solution is sprayed into a macromolecular crowding agent solution, and recombinant collagen is converted into a solid state from a solution state by utilizing a macromolecular crowding effect of the macromolecular crowding agent, so that the collagen microspheres are prepared, a cross-linking agent is not needed, and the biocompatibility and the safety of the prepared microspheres are improved.

The invention discloses injectable poly-L-lactic acid microsphere composite gel capable of inducing rapid regeneration and instant filling of collagen, which is characterized in that poly-L-lactic acid is used as a raw material, and poly-L-lactic acid microspheres are prepared by adopting an emulsification method; the preparation method comprises the following steps: taking collagen and oxidized polysaccharide as raw materials, carrying out Schiff alkali cross-linking reaction on the collagen and the oxidized polysaccharide to prepare composite gel, and uniformly distributing L-polylactic acid microspheres in the composite gel. The aldehyde group on the oxidized polysaccharide and the amino group on the collagen are subjected to a Schiff base cross-linking reaction to form the injectable gel with a three-dimensional network structure. The cross-linked gel provides mechanical tension to uniformly disperse the PLLA microspheres, so that the microspheres are prevented from settling or agglomerating. The composite gel can also improve the hydrophilicity of the microspheres, so that the redissolution dispersity of the microsphere filler is better, and the microspheres settle more slowly. After being injected subcutaneously, the collagen gel can be instantly filled and induce rapid regeneration of collagen, has no chemical cross-linking agent residue, and reduces the risk of inflammation (such as granuloma) caused by the organism and the like.