672 results about "Dextran" patented technology

The invention belongs to the technical field of gene engineering, and particularly relates to applications of OpgG and a mutant thereof in production of human milk oligosaccharide. The invention provides a dextran biosynthetic protein OpgG mutant, and the OpgG mutant is obtained by mutating the 443rd amino acid from threonine to proline on the basis of a wild type dextran biosynthetic protein OpgG as shown in SEQ ID NO.1. The invention also provides a preparation method of the dextran biosynthetic protein OpgG mutant. An opgG gene and / or a T443P mutant coding gene are / is introduced into a human milk oligosaccharide production strain and applied to production of human milk oligosaccharide, and the yield of 3 '-SL, 6'-SL, LNT II, LNnT and LNT is greatly increased.

A skin cleansing formulation is provided, comprising: a dermatologically acceptable vehicle; a dermatologically acceptable oil; and a deposition aid polymer, wherein the deposition aid polymer is a cationic dextran polymer, comprising a dextran polymer functionalized with quaternary ammonium groups; wherein the deposition aid polymer enhances the deposition of the dermatologically acceptable oil from the skin cleansing formulation onto mammalian skin.

The invention belongs to the field of biology, and discloses a CRISPR / Cas12a freeze-dried microsphere, which is characterized in that the CRISPR / Cas12a freeze-dried microsphere is obtained by freeze-drying the following raw materials: enzyme-free water, 10 * HOLMES Buffer for Cas12a, an RNA enzyme inhibitor, CRISPR / Cas12a protein, crRNA, an upstream primer F, a downstream primer R, a fluorescent probe Reporter and a freeze-drying protective additive; the CRISPR / Cas12a protein is an LbaCas12a protein, and the CRISPR / Cas12a protein is a Cas12a protein; the freeze-drying protective agent is prepared from mannitol, trehalose, polyethylene glycol, glucan and BSA (Bovine Serum Albumin). By further optimizing a freeze-drying protective agent, freeze-drying microballing of a CRISPR / Cas12a system is achieved, the freeze-drying microballing can be matched with RPA constant-temperature amplification double microballing, and detection is conducted through a one-step method. Meanwhile, the invention further discloses a three-microsphere detection system, application and a kit.

The invention relates to a medicine for repairing skin wounds and a preparation method thereof, and belongs to the technical field of biological medicines.The medicine is prepared from, by mass, 25-30 parts of bee embryo peptide, 8-10 parts of alkannin derivative, 10-15 parts of armillaria mellea polysaccharide, 8-10 parts of inonotus obliquus polysaccharide, 6-8 parts of notoginsenoside and 5-7 parts of astragaloside. The bee fetus peptide is a product which is more than 500Da and is obtained by performing step-by-step enzymolysis on bee larva freeze-dried powder through trypsin and bacillus subtilis neutral protease to obtain enzymatic hydrolysate which is less than 3kDa, performing purification through a G-50 sephadex column, performing ultrafiltration and performing freeze-drying. The alkannin derivative is obtained by reacting alkannin with succinic anhydride and glucosamine-polyethylene glycol. A special method is adopted for preparing the bee embryo peptide and alkannin derivatives, the bee embryo peptide and alkannin derivatives are matched with other components to play a synergistic role, and the effects of high safety, high skin cell proliferation promoting capacity, excellent antibacterial performance and the like are achieved.

The invention relates to the technical field of immune carrier microspheres, in particular to an immune carrier microsphere constructed by individualized MHC-II combined polypeptide, a vaccine and application of the immune carrier microsphere and the vaccine. A core comprises microspheres constructed by a plurality of MHC-II binding polypeptides, sequences of the MHC-II binding polypeptides are obtained based on HLA gene typing results of an inoculator, and each HLA gene corresponds to at least one high-affinity MHC-II binding polypeptide; a shell is a glucan with sulfydryl or other polymer coating layer, and sulfydryl is used as a coupling group to be connected with an antigen to construct the vaccine. The method has the advantages that competition is avoided, inhibition is generated, a better immune effect is achieved, antibodies of high-titer carrier molecules are not generated, and cross reaction side effects are avoided. The carrier molecular diversity is reduced; side effects are avoided. And antibody immunity and cellular immunity functions are generated. The particle size of the microspheres is controllable, and the immunologic function can be achieved without adjuvants. The preparation process is simple to operate and good in repeatability.

The invention relates to efficient anti-dandruff shampoo and a preparation method thereof, and belongs to the technical field of shampoo. The efficient anti-dandruff shampoo comprises the following raw materials: 0.7%-1% of a plant extract, 0.04% of asiatic acid, 30%-35% of a humectant, 7%-10% of a surfactant, 18% of sodium propionate, 2%-4% of a thickener, 0.2%-0.3% of an emulsifier, 0.8%-1% of an acidity regulator, 0.05% of tremella polysaccharide, 2%-3% of dextran enzyme, 0.3%-0.5% of a preservative, 2%-3% of a conditioner, 0.5% of isethionate and the balance of deionized water. Three effective components including lophatherum gracile ketone, cacumen biotae extract and cnidium monnieri extract are prepared into microcapsules to be added into the shampoo, the microcapsules are mixed with asiatic acid and an anti-dandruff component isethionate, and through the combined action of all the components, the purpose of effectively removing dandruff is achieved.

The invention belongs to the technical field of biology, and particularly relates to a high-throughput preparation method of a single-cell-derived organoid based on a microcapsule spherical shell structure, and the preparation method comprises the following steps: preparing an aqueous two-phase microcapsule encapsulated with a single cell, culturing the single cell in the aqueous two-phase microcapsule to obtain the organoid, the substances of the inner phase and / or the outer phase respectively comprise any one or a combination of more of the following substances: methacrylated gelatin, carboxymethyl cellulose, glucan, sodium alginate and polyvinyl alcohol. The invention also provides the organoid prepared by the preparation method and application of the preparation method. According to the invention, the microcapsule with a permeable core-shell structure is formed by packaging the microcapsule in a single-cell form in two-aqueous-phase liquid drops, the wrapping rate is effectively controlled and adjusted on the premise of conforming to Poisson distribution by optimizing parameters, and the single-cell wrapping rate and the organoid single-cell induction efficiency are optimized.

The invention relates to the field of animal consumer goods, and particularly discloses application of glucan in preparation of animal products for relieving pet stress syndromes. Pet experiments find that beta-1, 3 / alpha-1, 3-glucan can improve the stress syndromes of the indoor cats, specifically, abnormal behaviors of the cats are corrected, and abnormity of multiple systems of organisms such as the immune system, the endocrine system and the urinary system is improved. And when the method is applied to pets, the life quality of the pets can be remarkably improved, more emotional support is provided for pet owners, and the method has practical popularization and application values.

The invention discloses a preserving fluid for stably preserving sample DNA at normal temperature and a preparation method thereof, and belongs to the technical field of biological sample preservation. The preserving fluid comprises a lysis system, a nucleic acid protection system and a buffering and stabilizing system, the cracking system comprises a composite surfactant and an enzymolysis auxiliary agent; the composite surface active agent is prepared from polyether polyol fatty acid ester and cocamidopropyl hydroxy sulfobetaine; the enzymolysis auxiliary agent comprises lysozyme Lyso-V and protease K; the nucleic acid protection system comprises a nitrogen heterocyclic polyamine-carboxylic acid derivative and dextran sulfate; the nitrogen heterocyclic polyamine-carboxylic acid derivative comprises 1, 4, 7, 10-tetraazacyclododecane-N, N ', N' ', N ''tetraacetic acid, 1, 4, 7-triazacyclononane-N, N', N''-triacetic acid, disodium ethylene diamine tetraacetate-nitrogen heterocyclic derivative, and diethylenetriamine pentaacetic acid-piperazine derivative, and the nitrogen heterocyclic polyamine-carboxylic acid derivative comprises 1, 4, 7, 10-tetraazacyclododecane-N, N ', N '', N'' tetraacetic acid, 1, 4, 7-triazacyclononane-N, N', N ''-triacetic acid. The buffering and stabilizing system comprises an amphoteric buffering agent and a polymer stabilizer; the amphoteric buffering agent comprises 2-(N-morpholino) ethanesulfonic acid and N-tri (hydroxymethyl) methylglycine.

The invention relates to the technical field of preparation of biological materials and pharmaceutical preparations, in particular to organic composite hydrogel as well as a preparation method and application thereof. The specific preparation method comprises the following steps: dissolving a targeted drug in orthoester to obtain a targeted drug-orthoester solution; the preparation method comprises the following steps: mixing an oxidized dextran solution, a targeted drug-orthoester solution and a carboxymethyl chitosan solution, carrying out vortex treatment, and standing to prepare the organic composite hydrogel. The solubility of the targeted drug in the hydrogel is improved by utilizing orthoester, the orthoester can carry the targeted drug to efficiently escape from the hydrogel, and the targeted drug can be self-assembled to form nanoparticles along with degradation of the orthoester in the escape process, so that the retention capacity of the targeted drug at a tumor site is enhanced, and the targeting drug can be used for treating tumor tumors. The drug enrichment capacity is improved, meanwhile, the toxic and side effects of the whole body are reduced, and the problems that nano-drugs are poor in solubility, still prone to being removed after intravenous administration and poor in enrichment effect at tumor sites are solved.

The invention relates to a medicine for skin regeneration and repair and a preparation method thereof, and belongs to the technical field of biological medicine, the medicine comprises cyperus esculentus extract peptide, brooklet anemone root tremella extract, rhodomyrtus tomentosa root-suberect spatholobus stem-radix cyathulae composite extract, pomegranate peel polyphenol and the like. The cyperus esculentus extracted peptide is a product which is more than 1kDa and is obtained by performing enzymolysis on cyperus esculentus through cellulase, alpha-chymotrypsin and ficin protease in sequence and then performing purification through a G-50 sephadex column; the tremellodon gelatinosum tremella extract is a product which is less than 3kDa and is obtained by performing common enzymolysis on tremellodon gelatinosum tremella sporocarp through cellulase and bromelain; the rhodomyrtus tomentosa root-suberect spatholobus stem-radix cyathulae composite extract is a product obtained by performing gradient extraction on rhodomyrtus tomentosa root, suberect spatholobus stem and radix cyathulae through an ethanol water solution to obtain an extract, and performing polyamide resin column adsorption and LH-60 sephadex column purification in sequence. A good repairing system is constructed by multiple components, and wound repairing and healing are accelerated.

The invention discloses injectable hydrogel for alveolar bone repair, the injectable hydrogel comprises a first component and a second component, the first component comprises 4-carboxyl-3-fluorophenylboronic acid modified carboxymethyl chitosan CMCS-FPBA and beta-tricalcium phosphate, and the second component comprises oxidized dextran, PPS-HA nano-micelle and curcumin. The invention also discloses a preparation method and application of the injectable hydrogel. The injectable hydrogel disclosed by the invention has the effects of resisting oxidation, resisting inflammation and promoting bone tissue regeneration, is high in biocompatibility, can be customized in a personalized manner, and can be used for repairing alveolar bones.

The invention belongs to the technical field of biological medicines, and particularly relates to application of extracellular vesicle-like particles derived from divaricate saposhnikovia roots in preparation of medicines for preventing and treating intestinal diseases. Research on the physiological efficacy of the extracellular vesicle-like particles from divaricate saposhnikovia root shows that the extracellular vesicle-like particles can relieve colon shortening and colon tissue damage caused by dextran sodium sulfate, relieve intestinal inflammation and promote repair of intestinal barriers including mechanical barriers, chemical barriers and immune barriers. The polypeptide has potential for preparing the medicine for treating the intestinal diseases, and a new strategy is provided for preventing or treating the intestinal diseases.

The invention relates to the technical field of biological medicine, in particular to a diagnosis and treatment integrated brain-targeted magnetic particle imaging tracer and a preparation method and application thereof. The preparation method comprises the following steps: loading tetrahydrocurcumin into glucan by adopting a nano-particle self-assembly technology to form glucan nano-particles loaded with tetrahydrocurcumin, synthesizing Fe3O4 nano-particles by adopting a chemical precipitation method, and embedding the Fe3O4 nano-particles on the glucan nano-particles to obtain the diagnosis and treatment integrated brain-targeted magnetic particle imaging tracer agent. The nano-particles are marked as THC (at) Dex-Fe3O4 nano-particles. The THC-Dex-Fe3O4 nanoparticles play a role in treating the Alzheimer's disease during brain imaging diagnosis, and the technical problems that magnetic particle imaging cannot be applied to diagnosis of the Alzheimer's disease and the Alzheimer's disease is difficult to treat are solved.

The invention discloses application of copper-amino acid nano enzyme in preparation of anti-inflammatory drugs, and relates to the technical field of biomedical new materials, amino acids comprise glycine, arginine, histidine, threonine, phenylalanine and cysteine; the ratio of the amino acid to the copper ions is 1: (0.5-5), and the synthesis temperature of the copper-cysteine nano enzyme is 25-125 DEG C. The copper-amino acid nano-enzyme library established by the invention has efficient hydroxyl free radical, superoxide free radical and hydrogen peroxide scavenging activity; wherein the copper-cysteine nano-enzyme shows the highest enzymatic activity, and shows low toxicity and good biocompatibility in both the cell level and the animal level; meanwhile, the copper-cysteine nano-enzyme also shows anti-inflammatory activity and anti-oxidative stress activity, can remarkably improve cell inflammation and body inflammation, relieves and treats dextran sodium sulfate induced mouse ulcerative colitis, and can be further applied to preparation of drugs for treating inflammatory bowel diseases.

The invention discloses a diabetic bone defect repair hydrogel stent capable of slowly releasing exosome and a preparation method of the diabetic bone defect repair hydrogel stent. The preparation method comprises the following steps: preparing biotinylated quaternized chitosan methacrylate (QCS-MA-Biotin), formylated oxidized dextran and a biotinylated exosome (Exo-Bio), carrying out avidin bridging, and carrying out photocuring, so as to form the double-network hydrogel. The scaffold disclosed by the invention has a pH-responsive slow-release characteristic, the 28-day release rate of the exosome is less than or equal to 50%, and the activity retention rate gt; in addition, the repair of the diabetic bone defect can be obviously promoted. The method is suitable for repairing defects of skull, alveolar bone and the like.

The invention discloses a polymer material, a drug-loaded micelle solution, a drug-loaded micelle composite hydrogel, and a preparation method and application of the drug-loaded micelle composite hydrogel. The polymer material is obtained by reacting oxidized dextran and oleylamine; wherein the oxidized dextran is obtained by oxidizing dextran with the molecular weight of 35000 to 45000; the oxidation degree of the oxidized dextran is 55-70%; the mass ratio of the oxidized dextran to the oleylamine is 1: (1.2-2.0). The polymer material provided by the invention can form a micelle as a carrier to entrap a hydrophobic drug, such as prednisolone. The drug-loaded micelle composite hydrogel provided by the invention can be used for treating inflammatory bowel disease IBD, can avoid damage of an acid environment to a greater extent, and prolongs the administration time.

The present invention relates to an advanced dressing characterized by a powder of polymeric material based on poly(lactic-co-glycolic) acid, functionalized with dextran, maltodextrin, collagen, citric acid, chitosan, polyphenols, colloidal silver, hyaluronic acid and / or salts thereof, polyethylene glycol and alginate. The present invention further relates to a process for producing the powder and the use of the powder in treating non-necrotic skin wounds.

The invention provides a radix tetrastigme polysaccharide and application thereof in a medicine for treating diabetic retinopathy. The radix tetrastigme polysaccharide is prepared by the following steps: deproteinizing a water extract of radix tetrastigme by using CaCl2, depigmenting by using activated carbon, performing column chromatography, eluting by using a NaCl solution, merging and collecting eluent components, concentrating under reduced pressure, dialyzing by using a dialysis bag with an interception value of 0.5 KDa, and performing vacuum freeze drying. And performing further chromatography by using Chromdex 200PG sephadex gel, collecting the components, and performing freeze drying to obtain the homogeneous polysaccharide with the average molecular weight of 36.848 KDa. Meanwhile, pharmacological activity evaluation is carried out on the radix tetrastigme polysaccharide, it is found that the polysaccharide can reduce the free Fe < 2 + > level and reverse high glucose induced ARPE19 cell damage, and in addition, animal experiments also prove that the radix tetrastigme polysaccharide can reduce the DR rat retina Fe < 2 + > level and relieve diabetic retinopathy; the research can provide a scientific basis for research and development of a novel natural medicine radix tetrastigme polysaccharide for treating DR.

The present application relates to a kind of pH / H2O2 dual-response drug-loaded hydrogel and its preparation method and application, by ε-polylysine derivative as antitumor active ingredient, with oxidized dextran through Schiff base reaction crosslinking rapid gelation. While using 2-formylphenyl boronic acid covalently package CD73 small molecule inhibitor APCP. ε-polylysine derivative has oncolytic activity, can induce ICD and promote the infiltration of immune cells in tumor cells. CD73 small molecule inhibitor APCP can block extracellular CD39-CD73-adenosine pathway, reduce the level of immunosuppressive metabolite adenosine in tumor tissue, so as to activate the infiltrated immune cells, restore its anti-tumor function. The hydrogel of ε-polylysine derivative and APCP co-delivery synergistically inhibits the effect of tumor growth, and its curative effect is greater than the treatment effect of single drug, and is superior to positive control drug oxaliplatin (OXA). The pH / H2O2 dual-response hydrogel is rapidly gelled, and has good biological safety under mild reaction conditions.

The invention relates to the field of biological environmental protection, in particular to a heterotrophic nitrification immobilized engineering bacterium for efficient denitrification and a preparation method and application thereof.According to the heterotrophic nitrification immobilized engineering bacterium for efficient denitrification and the preparation method and application of the heterotrophic nitrification immobilized engineering bacterium, polyethylene glycol-glucan two-aqueous-phase concentration and trehalose protection liquid are adopted for synergistic effect, the bottleneck of cell damage caused by a traditional flocculation method can be avoided, trehalose molecules can wrap bacterial cells, and the bacterial cells can be effectively degraded; the immobilized particles can resist osmotic pressure impact and pollutant invasion, the survival rate of thalli is higher than 95%, so that the immobilized particles always keep ultrahigh denitrifying enzyme activity in various sewage environments, honeycomb-shaped pores are formed in an ethyl cellulose matrix, a microenvironment with a high specific surface area is provided for thalli attachment, and the built-in nano zeolite continuously and slowly releases Cu < 2 + > and Zn < 2 + > trace elements, so that the immobilized particles can be recycled. A thallus metabolism enzyme system is synergistically activated, and the denitrification pathway function is enhanced; the chitosan-polydopamine outer coating layer strongly captures the nitrogen-containing pollutants, so that the removal efficiency of the nitrogen-containing pollutants is improved; through triple protection, the density of unit granular bacteria is up to 109 cells / cm, the service life is prolonged, and the denitrification performance is improved by more than 40%.

The invention discloses a crocodile polypeptide with anti-inflammatory and intestinal flora regulating functions and a preparation method thereof, belongs to the technical field of functional polypeptide preparation, and particularly relates to a preparation method of the crocodile polypeptide, an anti-inflammatory effect of the crocodile polypeptide and a regulating effect of the crocodile polypeptide on intestinal flora in ulcerative colitis inflammation. According to the preparation method, the crocodile polypeptide is prepared by combining multiple physical processing with enzymolysis, so that the purity and the biological activity of the crocodile polypeptide are improved. On the basis, a lipopolysaccharide-induced THP-1 in-vitro cell inflammation model and a dextran sodium sulfate-induced mouse in-vivo ulcerative colitis inflammation model are established, and the in-vivo and in-vitro anti-inflammatory effect of the crocodile polypeptide is further researched. The crocodile polypeptide prepared by the invention has a remarkable inhibition effect on THP-1 cell inflammation induced by lipopolysaccharide. Meanwhile, the crocodile polypeptide prepared by the preparation method disclosed by the invention has an adjusting effect on intestinal flora. The food or functional food with the effects of relieving ulcerative colitis and regulating intestinal flora can be prepared.

A WG-DNPs-stabilized Pickering emulsion and its application in β-carotene loading are disclosed. The emulsion is prepared by the following method: S1: Gluten protein and dextran form a covalent complex through Maillard reaction. The gluten protein complex is then prepared into a solution, and its pH is adjusted to neutral. The ionic strength of the solution is then adjusted to 15-25 mM using NaCl to obtain an intermediate solution. The intermediate solution is subjected to water bath heat treatment, ice bath cooling, and freeze drying sequentially to obtain WG-DNPs. S2: WG-DNPs are dispersed in distilled water to obtain a WG-DNPs dispersion. The WG-DNPs dispersion is mixed and homogenized with an oil phase to obtain the Pickering emulsion. This invention uses glycosylated gluten protein nanoparticles as a stabilizer for Pickering emulsions, giving the Pickering emulsions good thermal and storage stability. Furthermore, by loading β-carotene onto the Pickering emulsion stabilized by WG-DNPs, the bioavailability and digestive stability of β-carotene can be significantly improved, thus aiding in the human body's intake of β-carotene.

The invention discloses a construction method and application of a probiotic engineering bacterium EcNpAm targeting animal intestinal tracts and improving inflammation. According to the present invention, the heterologous expression of the immunomodulatory protein Amuc1100 is successfully achieved through the gene engineering technology by using the Escherichia coli Niss1917 (EcN) as the host and using the anaerobic inducible plasmid pnirBMisL as the expression vector, and the novel engineering bacterium EcNpAm suitable for the animal intestinal anaerobic environment is constructed; furthermore, the expression efficiency of the target protein is represented by fusion expression of green fluorescent protein (GFP). The engineering bacterium is applied to prevention and treatment of animal intestinal inflammation, and successfully realizes targeted delivery of therapeutic protein to intestinal tracts of mice. Experiments show that EcNpAm can effectively relieve typical symptoms such as weight loss, colon shortening, pathological injury, colitis and the like of mice induced by dextran sodium sulfate (DSS) and protect integrity and functions of an intestinal barrier structure.

The invention belongs to the technical field of antibacterial materials, and particularly relates to a nano-silver antibacterial agent, which is prepared from the following raw materials in parts by weight: 85 to 95 parts of nano-silver solution, 0.5 to 1 part of plant extract and 2 to 6 parts of carboxymethyl glucan. The invention further discloses a preparation method and application of the nano-silver antibacterial agent. The antibacterial agent is good in stability, the preparation process is environment-friendly and pollution-free, the preparation method is simple, and the antibacterial agent has an excellent sterilization effect and also has a certain inhibition effect on the growth of cancer cells.

The invention discloses a preparation method of crocodile liver peptide for improving liver injury, and relates to the technical field of bioactive peptide extraction, and the preparation method comprises the following steps: crocodile liver pretreatment: cutting fresh crocodile liver into blocks, mixing with deionized water, homogenizing, and adding a zirconium phosphate molecular sieve to obtain crocodile liver homogenate; enzymatic hydrolysis reaction: adjusting the pH value of the homogenate, and adding a compound enzyme preparation for enzymatic hydrolysis; carrying out enzyme deactivation treatment, namely heating, cooling, centrifuging and taking supernate; performing ultrafiltration separation, namely filtering the supernate through an ultrafiltration membrane, and collecting a small molecule peptide solution; purifying and refining: purifying through sephadex column chromatography, and freeze-drying to obtain a crocodile liver peptide product; a double-particle-size zirconium phosphate molecular sieve is constructed to cooperate with a compound enzyme preparation for enzymolysis, electron transfer is enhanced by combining phosphorylation modification, the defects of metal inhibition enzyme activity, insufficient concealed peptide fragment cutting and oxidative damage are overcome, meanwhile, the application of the crocodile liver peptide in the aspect of improving the liver function is researched, and the crocodile liver peptide has a good application prospect. And a new choice is provided for prevention and treatment of liver diseases and liver health care.

Surfactant compositions comprising a reaction product of a saccharide polymer and a fatty acid or a fatty ester may be obtained in an aqueous fluid in the presence of a hydroxide base and a neutral surfactant or a reaction product form thereof, the saccharide polymer comprising a dextran, a dextrin compound, or any combination thereof. One or more zwitterionic surfactants may be combined with the surfactant composition in a ratio sufficient to render the resulting combined surfactant composition brine-tolerant, even when both the reaction product and one or more of the zwitterionic surfactant(s) are brine-intolerant. The one or more zwitterionic surfactants may be further selected to render the combined surfactant composition non-emulsifying toward oleaginous fluids.

The invention relates to the technical field of graded screening, in particular to a graded screening system based on staggered stacked metal ring films and a preparation method and application. An organic ligand and two metal complexes are subjected to interface coordination assembly under the action of silver ions, an ordered staggered stacked metal ring film is constructed, the structure and performance of the metal ring film are precisely regulated and controlled, the metal ring film has a definite molecular sieve component difference, and then precise grading screening of different molecules is achieved. The film has an obvious lattice structure, has good crystalline orderliness, and can ensure the stability and reliability of the screening process. The graded screening system based on the staggered stacked metal ring membranes has excellent interception performance on target molecules, and effective separation of TAC from glucan and leucine can be achieved. The two-stage membrane classification screening strategy can also be popularized to separation and purification of other substances, and good universality and industrial application prospects are achieved.

The invention discloses composite hydrogel and application of the composite hydrogel in preparation of a diabetes wound repair dressing. The gel comprises Metformin (Met) loaded Mg-MOF / Met nano-particles, a hydrogel carrier and a hydrogel carrier, wherein the Mg-MOF / Met nano-particles are prepared from the following components of Mg-MOF / Met nano-particles; the hydrogel network is formed by cross-linking chitosan (CA) modified by arginine and oxidized dextran through a Schiff base reaction; wherein the Mg-MOF / Met nano particles are uniformly dispersed in the hydrogel network, and the Mg-MOF / Met nano particles are uniformly dispersed in the hydrogel network. An animal model verifies that after 14 days, the healing rate reaches 92.1%, the antibacterial rate is larger than 95%, the ROS clearance rate is 85.2%, the cell survival rate is larger than 95%, and remarkable application prospects are shown in the field of diabetes wound repair.

The invention belongs to the field of biomolecule detection, and discloses a polysaccharide high-throughput detection method and application. The method can be used for detecting the heparin precursor, a sample does not need to be purified, the heparin precursor in a complex sample can be directly recognized and degraded by enzyme specificity to generate disaccharide, and then the content of the disaccharide of the heparin precursor is detected through high-throughput EchoMS, so that the heparin precursor is subjected to rapid, high-throughput, qualitative and quantitative analysis; the method is used for screening and evaluating elements influencing heparin precursor synthesis, screening and evaluating heparin precursor synthesis strains, optimizing the heparin precursor fermentation process and the like. The method can also be used for high-throughput detection of glycosaminoglycans such as hyaluronic acid, heparin and chondroitin sulfate and other polysaccharides such as pullulan, curdlan, xanthan gum and glucan, and can be used for structural analysis of polysaccharides.