14results about How to "Lower immune response" patented technology

The invention discloses a composition as well as a preparation method and application thereof, and relates to the technical field of compound bacterium extract compositions. The compound bacteria comprise schizochytrium limacinum, acremonium terricola and gordonia alcalivorans; the mass ratio of the compound bacterium extract to the antioxidant is 100: (0.5-5). The preparation method of the composition comprises the following steps: adding the antioxidant into the compound bacterium extract, mixing, and drying to obtain the compound bacterium extract. The compound bacterium extract disclosed by the invention is rich in lipid and other components, and when the compound bacterium extract is applied to a laying hen feed, the cholesterol content in eggs can be effectively reduced on the premise of safety, no toxicity, no side effect and no influence on the production performance of laying hens, so that the low-cholesterol eggs are produced.

The invention provides a genetic transformation method and application of muskmelon. The genetic transformation method comprises the following steps: carrying out co-culture treatment on an infected muskmelon explant and agrobacterium engineering bacteria in a sugar-free culture medium, and the sugar-free culture medium does not contain soluble sugar. By using the method, the co-culture time can be prolonged to 7-9 days, the infection efficiency of agrobacterium tumefaciens can be remarkably improved, the growth of the agrobacterium tumefaciens can be slowed down, agrobacterium tumefaciens pollution in the bud induction process is avoided, meanwhile, the immunoreaction of explants in the co-culture process is reduced, and the genetic transformation efficiency is further improved. Compared with an existing melon genetic transformation method in which co-culture time lasts for 4 days by adopting a sugar-containing culture medium, the genetic transformation method provided by the invention adopts a sugar-free culture medium and the co-culture time is prolonged to 8 days, so that the melon transgenosis efficiency can be improved by 14 times or more. The invention also provides an application of the genetic transformation method in preparation of a melon genetic transformation product.

The invention discloses a near-infrared light nano probe as well as a preparation method and application thereof. The preparation method of the near-infrared nano probe comprises the following steps: dissolving polylactic acid-co-acetic acid in an acetonitrile solution, and adding lecithin and 1, 2-dipalmitoyl-sn-glycerol-3-phosphatidyl glycol to obtain a solution A; dissolving indocyanine green in an ethanol solution to obtain a solution B; and mixing the solution A and the solution B, and carrying out ultrasonic treatment to obtain the near-infrared nano probe. The near-infrared light nanoprobe can be used for imaging diagnosis of acute kidney injury, and effectively solves the problems of long diagnosis time, poor stability, high in-vivo clearance rate, low cell absorption rate and the like. Compared with existing ICG nano-particles, the ICG nano-particles are high in biological tissue penetrability, high in resolution ratio, low in phototoxicity and good in fluorescence imaging effect in an acute kidney injury model and have wide application prospects in AKI clinical diagnosis.

The invention is suitable for the technical field of skin dressings, and provides preparation and application of a polyphenol nano-liposome loaded i-PRF skin dressing, the skin dressing comprises oxidized sodium alginate, carboxymethyl chitosan, freeze-dried concentrated growth factors and oleuropein nano-liposomes, the concentration of the oxidized sodium alginate is 0.2-0.5 g / ml, the concentration of the carboxymethyl chitosan is 0.2-0.5 g / ml, the concentration of the freeze-dried concentrated growth factors is 0.2-0.5 g / ml, and the concentration of the oleuropein nano-liposomes is 0.2-0.5 g / ml. The concentration of the carboxymethyl chitosan is 0.2 to 0.5 g / ml, the concentration of the freeze-dried concentrated growth factor is 0.05 to 0.1 g / ml, and the concentration of the oleuropein nano-liposome is 0.125 to 1 ml / g. According to the skin dressing, the biocompatibility of the hydrogel is effectively improved, the sustained drug sustained release characteristic is shown, and the skin dressing has outstanding performance in the aspect of promoting wound healing.

The invention discloses an ISG15 overexpression cell line, an SRM-enriched exosome as well as a preparation method and application of the ISG15 overexpression cell line and the SRM-enriched exosome, and ISGylation modification of spermidine synthase SRM is induced by constructing an ISG15 overexpression stably transfected cell line, so that packaging and sorting of the spermidine synthase SRM into the exosome are promoted. The technical scheme disclosed by the invention shows that the spermidine synthase transmitted by the exosome has biological activity and can catalyze to generate spermidine after being absorbed by target tissues / target cells, so that the spermidine synthase has wide application prospects in multiple aspects of disease treatment, medical care, beauty treatment, young keeping and the like. In addition, other protein or polypeptide drugs can be modified through a genetic engineering technology to be subjected to ISGylation modification so as to be wrapped in the exosome, and simultaneous administration of multiple proteins is realized.

The invention provides a PEG / CaCl2 mediated Penicillium citrinum genetic transformation method, and belongs to the technical field of microbial genetic transformation, and the method comprises the following steps: adding a target gene segment into Penicillium citrinum protoplast suspension, and carrying out an ice bath reaction; the target gene segment is obtained by taking pJET-hph-02944 plasmid as a template and carrying out PCR (Polymerase Chain Reaction) amplification by adopting a hygromycin B resistance gene primer pair with gene sequences as shown in SEQ ID No. 1 and SEQ ID No. 2; adding a PTC (Positive Temperature Coefficient) buffer solution into the mixed system, uniformly mixing and standing; continuously adding a TB3 liquid culture medium containing ampicillin, and carrying out recovery culture; uniformly mixing the resuscitated protoplast with a molten TB3 solid culture medium, pouring a plate, and carrying out dark culture for the first time; then covering a TB3 solid culture medium containing hygromycin B and ampicillin, carrying out secondary dark culture to obtain a transformant, and transferring the transformant to a PDA plate containing hygromycin B for screening. According to the method, CaCl2-PEG is adopted for mediated transformation of Penicillium citrinum, the transformation efficiency is higher, and the transformation speed is higher.

The invention discloses a hybrid cell membrane disguised hexagonal boron nitride nano-particle as well as a preparation method and application thereof, relates to the technical field of medicines, and aims to solve the problems of poor targeting property and biocompatibility of a boron carrying agent, insufficient in-vivo stability and tumor accumulation capacity of nano-particles and the like in BNCT tumor treatment in the prior art. The composite material comprises hexagonal boron nitride nanoparticles and a hybrid cell membrane coating the peripheries of the hexagonal boron nitride nanoparticles, and the hybrid cell membrane is formed by fusing a macrophage cell membrane and a tumor cell membrane. The targeting property and biocompatibility of the boron carrying agent and the in-vivo stability and tumor accumulation capacity of nanoparticles can be effectively enhanced, and the BNCT treatment effect of glioma is improved.

It is desirable to provide a novel biomaterial and the like for tendon repair. Provided is a biomaterial for tendon repair containing a hydrogel formed by means of a cross-linking reaction between a reactive group A and a reactive group B, wherein the hydrogel contains a water-soluble polymer having the reactive group A, and mesenchymal stem cells having the reactive group B.

The invention discloses a gamma-PGA synthetase gene cluster pgsBCA '. The gamma-PGA synthetase gene cluster pgsBCA' is formed by sequentially connecting genes pgsB, pgsC and pgsA 'in series, the genes pgsB and pgsC are derived from a gamma-PGA synthetase gene cluster BA-pgsBCA of the bacillus altitudinis; the gene pgsA'is derived from a gamma-PGA synthetase gene cluster BM-pgsB 'C' A 'of bacillus megatherium. Bacillus amyloliquefaciens CF of which a genome knockout polyglutamate synthetase gene cluster is used as a host, and a recombinant polyglutamate synthetase gene cluster pgsBCA'is subjected to free expression through plasmids, so that a gene engineering strain capable of synthesizing gamma-L-PGA is obtained. When the strain is used for producing gamma-L-PGA in a 5L fermentation tank through amplification fermentation, the maximum yield can reach 10.5 g / L. Besides, the gamma-poly-L-glutamic acid is free of cytotoxicity and low in immunogenicity, so that the gamma-poly-L-glutamic acid has a wide application prospect in the fields of preparation of wound dressings, in-vivo absorption materials and the like. The invention provides a new material basis and technical support for application and development of polyglutamic acid in the fields of medicine and related biomedicine.

The invention belongs to the field of medical materials, and particularly relates to an acellular dermal matrix and a cross-linking modification method thereof. According to the method, the acellular dermal matrix (ADM) is subjected to cross-linking modification by adopting glutamine transaminase (TG enzyme) in a mild and easy-to-operate manner, so that the physical and mechanical properties, the biocompatibility and the biological activity of the acellular dermal matrix (ADM) are improved. The thermal denaturation temperature, the thermal shrinkage temperature, the tensile strength and the like of the ADM dressing modified by glutamine transaminase (TG enzyme) are remarkably improved, and the ADM dressing has low immunogenicity and controllable degradability. The method can be used for preparing high-end dressings, hemostatic membrane materials, biological tissue patches, soft tissue repair materials, tissue engineering scaffold materials and the like, and has wide clinical application prospects.

The invention discloses a preparation method of a high-biocompatibility animal-derived decellularized tissue scaffold material, and relates to the technical field of cell tissue preparation. The method comprises the following steps: washing tissues such as small intestines of pigs with normal saline containing double antibodies and lysozyme; oscillating by using a mixed solution of TritonX-100 and the like, treating by using a solution of nuclease and the like, digesting by using a mixed solution of multiple enzymes, and washing by using ultrapure water containing chitosan; then carrying out ultrasonic disinfection by using a disinfectant containing nano-silver, and sealing by using a solution containing fetal calf serum and the like; after freeze drying, genipin is used for cross-linking and loading growth factors and the like, and finally a dopamine solution is used for modification, so that the scaffold has better hydrophilicity and cell adhesiveness. The cell residue rate of the scaffold is lower than 3%, the nucleic acid residue is low, and the immunogenicity is effectively reduced; the composite material has the advantages that extracellular matrixes are reserved, the mechanical property is good, the controllable bioactive substance release function is achieved, the characteristics of antibiosis, antioxidation and the like are achieved, the biocompatibility is good, and the application prospect is wide.

The present invention belongs to the field of nano drug preparations, and specifically relates to a method for preparing a composite nanocarrier using inhalable liposomes and mannose-modified chitosan, and its application in the treatment of acute lung injury. The composite nanocarrier prepared by the present invention contains inhalable liposomes, which can act directly on the lungs, effectively avoid the first-pass effect of the liver, reduce systemic side effects, prolong the action time of the drug, and improve the bioavailability of the drug. Furthermore, by using mannose-modified chitosan to coat the inhalable liposomes, the composite nanocarrier can be specifically bound to the mannose receptor on the surface of macrophages, thereby achieving sustained-release targeted delivery of the drug, and surprisingly, the composite nanocarrier containing two drugs, miR-214 inhibitor and curcumin, can achieve the effect of synergistic treatment of acute lung injury under a suitable mass ratio.

This invention belongs to the field of genetic engineering technology, specifically relating to a modular tandem repeat recombinant type III collagen with high platelet adhesion and its applications. The amino acid sequence of the recombinant type III collagen includes repeating units, with ≥3 repeating units; functional modules are inserted within each repeating unit. This invention integrates multiple discrete platelet-binding sites in type III collagen, designs a tandem repeat structure of different modular sequences (≥3 repeating units), optimizes spatial synergy, optimizes the gene sequence using codon bias, efficiently expresses the gene through a Pichia pastoris expression system, and obtains a high-purity product after purification. The recombinant type III collagen prepared by this invention exhibits good biocompatibility and can significantly promote erythrocyte and platelet adhesion; it can be widely used in wound repair, hemostatic materials, and tissue engineering.

The invention provides a multifunctional composite neural electrode system and a preparation method, and belongs to the technical field of implanted electrodes, specifically, the multifunctional composite neural electrode system comprises an electrode main body, a circuit adapter plate, a fixed frame, a catheter structure and a replaceable inner core, the electrode main body comprises an insulating substrate, a metal wiring layer and an insulating layer which are stacked in sequence, the electrode main body is provided with an electrical detection site and a leading-out bonding pad, a metal wiring layer at the electrical detection site and the leading-out bonding pad is exposed, the replaceable inner core comprises an implantation guide needle, an optical fiber and an injection inner tube, and the replaceable inner core is inserted from one end, far away from the tip of the electrode main body, of the sleeve, enters the implantation tube through the insertion core and extends out of the far end of the implantation tube. By designing a universal catheter structure and a replaceable inner core, the neural electrode realizes multi-mode nerve detection or stimulation, multiple functions are selected according to actual requirements, and integration of all functional parts is avoided, so that the overall structural size is reduced, and the damage to the brain in a long-term experiment can be reduced.