343 results about "Cross-Linking Reagents" patented technology

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 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 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.

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 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 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 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 provides vitamin B12 modified microspheres capable of efficiently loading His tag recombinant protein as well as a preparation method and application of the vitamin B12 modified microspheres, and belongs to the technical field of biological medicines. The preparation method of the vitamin B12 modified microsphere for efficiently loading the His tag recombinant protein comprises the following steps: (1) carrying out esterification reaction on unsaturated fatty acid containing sulfydryl, disulfide bond or olefinic bond, saturated fatty acid and vitamin B12 to prepare an amphiphilic vitamin B12-lipid conjugate; and (2) taking the amphiphilic vitamin B12-lipid conjugate, PLGA (poly (lactic-co-glycolic acid)), a multi-sulfydryl cross-linking agent and a photoinitiator as raw materials, and preparing the raw materials into microspheres by adopting a microfluidic method, so as to obtain the vitamin B12 modified microspheres capable of efficiently loading various His tag recombinant proteins. The microsphere provided by the invention overcomes the problems of protein load stability and burst release of traditional microspheres, and various different His tag recombinant growth factors can be flexibly selected according to the requirements on different growth factors in treatment of complex bone defects caused by different pathogenesis.

The present disclosure provides compositions and methods for conjugating a target polypeptide and a target oligonucleotide. More particularly, the present disclosure provides compositions and methods for making and using a recombinant protein harboring a domain recognizing a nucleic acid and a domain capable of binding and crosslinking with antigen-binding polypeptides.

The invention belongs to the technical field of biomedical materials, and discloses a viola philippica exosome-loaded composite hydrogel as well as a preparation method and application thereof, the composite hydrogel is prepared by mixing methacrylated polylysine (PLMA), oxidized dextran (ODex), viola philippica exosome (V-E), a photoinitiator and a physiologically compatible solvent and performing illumination crosslinking; the preparation method comprises the following steps: respectively preparing PLMA and ODex solutions, extracting and purifying V-E, adding a photo-crosslinking agent (LAP), mixing the components to obtain a precursor liquid, and carrying out in-situ curing molding through ultraviolet-visible light irradiation. The composite hydrogel provided by the invention solves the problems that the existing wound dressing is difficult to fit with irregular wounds, is antibacterial and easy to resist drugs, and lacks active anti-inflammatory and efficient healing promotion capabilities, and is suitable for repair treatment of infectious open wounds such as burns, trauma, diabetic foot ulcer and postoperative infected incisions.

The application belongs to the technical field of biological medicine, and discloses a cyclic peptide molecule specifically targeting CD5 and purposes thereof. The surface receptor CD5 of immune cells (T cells, B cells) has been proved to be a potential tumor treatment target, the present application uses the phage display technology widely applied to the development of polypeptide or antibody drugs to carry out multiple rounds of in vitro screening on human CD5 protein, and obtains a cyclic peptide molecule with drug potential and capable of specifically combining with CD5 through second-generation sequencing. The cyclic peptide molecule contains two cysteines, is modified into a ring through a specific chemical crosslinking agent, and the affinity of the cyclic peptide molecule to CD5 is determined to be in the low micromolar level through surface plasmon resonance technology, thereby laying a foundation for the development of a CD5-targeting inhibitor.

The application provides a long-acting, non-embolism filling monodisperse chitosan microsphere, the base material of the microsphere is cross-linked chitosan, the cross-linked chitosan is formed by cross-linking reaction of component A and a cross-linking agent, or formed by cross-linking reaction of component A, component B and the cross-linking agent; the component A is at least one of chitosan and modified chitosan, and the component B is at least one of hyaluronic acid, collagen and gelatin; the particle size of the microsphere is 20-120 mu m, and the variation coefficient of the microsphere particle size is not more than 5%. The application also provides a preparation method of the microsphere. The monodispersity of the microsphere is excellent, the degradation time is relatively longer, the water absorption performance is good, the embolism risk can be reduced, the filling effect maintaining time can be prolonged, and the effect of improving wrinkles can be increased, and the problems of short filling effect maintaining time and easy to cause blood vessel embolism of the filling hyaluronic acid product used in the existing medical and beauty field can be solved.

The invention provides a double-layer collagen scaffold repair membrane as well as a preparation method and application thereof, and the preparation method comprises the following steps: extracting collagen from animal fur, and emulsifying to obtain a collagen emulsion; adding a cross-linking agent into the collagen emulsion, and emulsifying to obtain a cross-linked protein emulsion; pouring the cross-linked protein emulsion into a mold, and freeze-drying to obtain a cross-linked protein layer; and pouring the collagen emulsion on the cross-linked protein layer, and freeze-drying to obtain the double-layer collagen scaffold repair membrane. The repairing membrane is excellent in structure, the cross-linked protein layer provides mechanical strength and supporting performance, the collagen layer can be rapidly dissolved and attached to the contact surface, and oxygen exchange and metabolite discharge of the wound surface are facilitated; the collagen is high in purity, low in antigenicity and high in safety, any toxic and harmful chemical reagents and preservatives are not added, allergy or inflammatory reaction is avoided, and the collagen has good application prospects in the fields of medical treatment, medical beauty, beauty, skin care and the like.

The invention discloses composite hydrogel for wound repair as well as a preparation method and application of the composite hydrogel, and belongs to the technical field of medical materials. The preparation method comprises the following steps: mixing methylacryloylated gelatin, hydroxyethyl methylacrylate and oxidized dextran, adding copper sulfide nanoparticles, a cross-linking agent and a photoinitiator, uniformly stirring, placing in a mold, irradiating by adopting ultraviolet light, carrying out Schiff base reaction on an aldehyde group on an ODex chain and an amino group on a GelMA chain to form a dynamic covalent bond, and forming a reversible cross-linking point, so as to obtain the copper sulfide nanoparticle / GelMA composite hydrogel. The preparation method comprises the following steps: carrying out a copolymerization reaction on HEMA and methacryloyl on a GelMA molecular chain to form a stable covalent cross-linked network, effectively capturing CuS NPs through a physical effect and stably dispersing the CuS NPs in the network in the process, and soaking the cross-linked hydrogel in deionized water for balancing to obtain the target composite hydrogel. The composite hydrogel has excellent mechanical strength, pH response swelling property and biocompatibility, can realize efficient antibacterial and endogenous immune regulation by combining near-infrared photothermal therapy, and effectively promotes wound repair.

This invention discloses a treatment process for high-concentration sulfate wastewater, belonging to the field of wastewater purification technology. The invention first provides a multifunctional composite ion sieve, the raw materials of which include magnetic core microspheres, calcium aluminate precursor components, heavy metal chelating agents, scale inhibitors, antioxidants, antibacterial agents, host-guest recognition agents, polysaccharide compounds, polyacrylic acid compounds, crosslinking agents, and initiators. The ion sieve is prepared through steps including magnetic core preparation, calcium aluminate precursor functional layer deposition, small molecule modification layer loading, and pH-responsive outer shell coating. In use, the ion sieve is added to wastewater and stirred for adsorption. After adsorption saturation, solid-liquid separation is achieved through magnetic separation, and the material is regenerated and recycled sequentially using desorption and reconstruction solutions.

The invention relates to a flame-retardant skin-friendly polyurethane sponge with in-situ reaction and bio-enzyme catalysis synergism. The water-based polyurethane foam is prepared from the following components: polyether polyol, diphenylmethane diisocyanate or toluene diisocynate, a chain extender, a high-efficiency foam stabilizer, a high-efficiency composite catalyst, water and ethanolamine phosphate, ethanolamine phosphate is added into water in advance, and then all the raw materials are mixed for polymerization foaming; after curing, spraying a spraying liquid consisting of phosphoethanolamine, regenerated protein and transglutaminase to generate a nano protein film, and synchronously performing vacuum suction to keep sponge pores unblocked. The preparation method has the advantages that a small amount of ethanolamine phosphate is added before polymerization foaming to serve as a phosphorus-nitrogen synergistic flame retardant and also serve as a catalytic cross-linking agent to participate in a reaction during polymerization, biological enzyme is added for catalysis after curing is finished, and the skin-friendly PU sponge with excellent flame retardance is prepared through in-situ polymerization reaction and biological enzyme enzymatic polymerization cooperation, and the sponge performance is not affected; the raw materials of the flame retardant come from biomass products and are environment-friendly and safe.

The application relates to the field of biomaterials, in particular to a preparation method of injectable acellular matrix powder and application thereof. The preparation method of the injectable acellular matrix powder is obtained through two discontinuous crosslinking steps of once crosslinking and twice crosslinking after crushing of acellular basement membrane. The obtained injectable acellular matrix powder with a unique crosslinking network structure is adapted to the natural skin pH value, greatly enhances the biocompatibility, simultaneously inhibits excessive inflammatory reaction and accelerates tissue healing through the induction of M2 polarized macrophage activation, effectively relieves the local tissue compression risk possibly caused by high cohesive force due to amino acid modification and introduction of a double crosslinking agent, realizes dynamic balance of mechanical stability and physiological friendliness, continuously stimulates the generation of skin collagen by using controllable moderate inflammatory reaction, and promotes gradual reconstruction and improvement of tissues.

This invention belongs to the field of biomedical materials technology, specifically relating to a chitosan hemostatic sponge and its preparation method. This patent addresses the problems of residual acetic acid and side reactions, low strength, and low absorbency caused by cross-linking methods during the preparation of chitosan hemostatic sponges. It innovatively proposes a method for physically cross-linking chitosan hemostatic sponges using hydrogen bonding-electrostatic synergistic superabsorbency based on alcohol-regulated substances. By introducing alcohols to regulate the electrostatic interaction between chitosan amino groups and acetic acid, while simultaneously adjusting the hydrogen bonding interaction between chitosan molecules, and introducing other polymer materials to construct a semi-interpenetrating network, the overall material properties are enhanced. The chitosan hemostatic material prepared by this process, although without the addition of cross-linking agents, still exhibits an insoluble sponge-like structure, good flexibility, and excellent absorbency and hemostatic effect.

The invention relates to the technical field of oilfield exploitation, and provides a self-healing gel plugging system with high wall surface binding capacity and a using method and application thereof.The plugging system is composed of self-healing gel, a wall surface binding agent and a self-healing inducer, and the wall surface binding agent serves as an intermediate to play a bridge role; a catechol group on one side of the nano-sheet has multiple interaction with active sites on the rock surface, and amino on the other side of the nano-sheet and an aldehyde group of a cross-linking agent form a Schiff base bond, so that a wall surface-nano-sheet-gel bridging structure is constructed, and a gel network is firmly anchored on the rock wall surface. The gel network can be crosslinked again to realize self-healing after being damaged by depending on an amino-aldehyde group dynamic reversible bond; the self-healing inducer gradually releases acidic components under stratum conditions, adjusts local pH, promotes aldehyde group-amino condensation crosslinking and improves the long-term stability of the system. Particle fluid channeling can be effectively inhibited, the water flooding swept volume is improved, and therefore the crude oil recovery rate is increased.

This invention relates to a hyaluronic acid composite hydrogel based on the supramolecular self-assembly of natural molecules and its preparation method, belonging to the field of gel formulation technology. The invention first involves the self-assembly of specific natural molecules or their derivatives possessing hyaluronidase inhibitory and anti-inflammatory activities into stable supramolecular self-assemblies through intermolecular non-covalent interactions. Subsequently, this supramolecular self-assembly is combined with hyaluronic acid through various interactions such as physical entanglement, hydrogen bonding, van der Waals forces, or appropriate chemical cross-linking to construct a composite hydrogel with a uniform internal structure and stable performance. This invention not only achieves long-term, controllable sustained release of natural active ingredients in the gel through supramolecular loading, continuously inhibiting hyaluronidase activity and local inflammatory responses, but also avoids the residual risks associated with high dosages of traditional chemical cross-linking agents, ultimately obtaining a high-quality product that meets the appearance and performance requirements of medical hyaluronic acid gels.

The application provides a sludge immobilization-based gel aerobic particle and a preparation method and application thereof, and belongs to the field of sewage treatment.The method comprises the following steps: 1, uniformly dispersing sEPS powder in a sodium alginate solution to obtain a composite gel; 2, filtering, centrifuging and removing supernatant of activated sludge in an aerobic tank to obtain concentrated bacteria solution; 3, adding the concentrated bacteria solution into the composite gel, uniformly mixing, dropping into a cross-linking solution, and then solidifying to obtain the gel aerobic particle.The sludge immobilization-based gel aerobic particle is prepared by using structural extracellular polymeric substances in activated sludge and sodium alginate to prepare a composite gel, and using a multivalent metal ion cross-linking agent to immobilize concentrated activated sludge, so that the gel aerobic particle with similar chemical composition, mechanical strength and biological performance to natural aerobic particles is prepared, and rapid granulation of sludge and rapid start-up operation of a granular system are realized.

Provided is a composition and method for delivery of bioactive agents to a cell or a subject. The composition includes nucleic acids derived from plants and the bioactive agents, and the nucleic acids are crossed linked by a cross-linking agent. Such composition is non-toxic, biocompatible and target specific. A method of making the composition is also provided.

The invention discloses a method for preparing a biomacromolecular drug delivery carrier based on a simple and efficient interface cross-linking system. An amphiphilic polymer monomer containing an epoxy group is prepared through RAFT polymerization so that the amphiphilic polymer monomer can exist on an oil-water interface, meanwhile, a three-arm cross-linking agent which has environmental sensitivity and is terminated by an amino group is prepared, and the amino group on the cross-linking agent and the epoxy group on the amphiphilic monomer are subjected to a cross-linking reaction on the oil-water interface; a drug delivery vehicle is formed. The carrier can entrap biomacromolecules and accurately target tumors through a high-permeability long-retention effect, and glutathione rich in a tumor microenvironment can break disulfide bonds in the carrier and release drugs entrapped in the carrier, so that the aim of treating the tumors is fulfilled. Therefore, the invention provides a drug delivery carrier which is simple, convenient, efficient in entrapment of biomacromolecules and high in stability, and the prepared carrier can be efficiently taken by tumor cells so as to regulate and control apoptosis of the tumor cells and is high in safety.

The invention provides a novel enriched photo-crosslinking agent, a preparation method of the novel enriched photo-crosslinking agent and application of the novel enriched photo-crosslinking agent in protein conformation and protein interaction analysis. The cross-linking agent can be subjected to a cross-linking reaction with protein at the moment of illumination, a cross-linked product can be enriched through click chemistry-biotin streptavidin, then steric hindrance of the cross-linked product is reduced by cutting azido biotin groups, and the mass spectrometric detection sensitivity and specificity of the cross-linked product are effectively improved.

The present application belongs to the technical field of protein composition, and relates to a collagen composition and a preparation method thereof. The present application provides a preparation method of a collagen composition, which comprises the following steps: preparing a collagen solution by treating raw hide which has not been subjected to chemical cross-linking treatment; adding a cross-linking promoter, an isothiocyanate and alpha-mammeigin to the collagen solution; and finally obtaining the collagen composition by multiple short-time microwave treatment. The collagen composition provided by the present application avoids the use of a cross-linking agent, has the advantages of no cytotoxicity, high cross-linking degree and good stability, and exhibits excellent antibacterial and antioxidant functions.

The invention relates to a glycosylated hemoglobin HbA1c freeze-drying detection reagent and a preparation method and application thereof.The preparation method comprises the steps that surface aminated polystyrene microspheres are prepared through an emulsion polymerization method, then double bonds are introduced through Schiff base reaction and methylacrolein reaction, and the glycosylated hemoglobin HbA1c freeze-drying detection reagent is obtained. Then preparing anionic polystyrene microspheres with hydrophilic chains through free radical polymerization, and preparing freeze-dried powder of the HbA1c detection reagent R1 by adopting the anionic polystyrene microspheres; the preparation method comprises the following steps: preparing a hydrophilic cross-linking agent 2, 5-bis (2, 4-dihydroxy-6-formylphenoxy) terephthalaldehyde, then carrying out a Schiff base reaction on the hydrophilic cross-linking agent 2, 5-bis (2, 4-dihydroxy-6-formylphenoxy) terephthalaldehyde and HbA1c mAb to prepare an HbA1c oligomer, and preparing the HbA1c detection reagent R2 freeze-dried powder by using the HbA1c oligomer. The glycosylated hemoglobin HbA1c freeze-drying detection reagent prepared by the invention has the advantages of high antigen binding efficiency, excellent detection sensitivity, sufficient retention of antibody activity and strong detection specificity.