43results about How to "Avoid immunogenicity" patented technology

The invention discloses a cellular silk fibroin porous scaffold, and a preparation method thereof. The method comprises the following steps of: degumming silkworm cocoon serving as a raw material, dissolving, dialyzing, and freeze-drying to obtain silk fibroin; and immersing a negative norm sodium chloride porous body which has a plant tissue structure and serves as a template in a silk fibroin solution, vacuum-drying at room temperature, performing beta treatment, and desalting to obtain the silk fibroin porous scaffold which has a bionic plant tissue cellular pore structure. The porosity of the prepared cellar silk fibroin porous scaffold is more than 80 percent, and the apertures of cellular pores are 50 to 300 mu m; and the cellular silk fibroin porous scaffold is high in biocompatibility, and matter permeability, and good in mechanical property and degradation property and the like. The scaffold is particularly suitable for a tissue engineering technology of peripheral nerve, tendon, ligament and the like which have longitudinal structural tissues, and can be widely applied to in-vitro three-dimension cell culture.

The invention provides a method for preparing a tissue engineering blood vessel based on a 3D (3-Dimensional) bioprinting technology. The method comprises the following steps:alternately printing a blood vessel shape by virtue of a high-polymer material and a human renascent skin fiber cell column, and removing the high-polymer material after fusion to structure a tissue engineering blood vessel; filling late-outgrowth endothelial progenitor cells into the blood vessel, and performing in-vitro dynamic culturing for 7 days in a bioreactor to obtain a differentiated tissue engineering blood vessel, wherein the high-polymer material is one of pluronic F127, poly(N-isopropylacrylamide), methyl cellulose and sodium alginate. The blood vessel obtained by the method is high in biocompatibility and higher in mechanical property, thrombus formation resistant and platelet adhesion resistance, and can be used for repairing and replacing a damaged or disease blood vessel.

The invention discloses a honeycomb polymer-based bionic porous scaffold material and a preparation method thereof. Natural plant tissues are used as templates. The method comprises the following steps of: performing vacuum carbonation, melting, permeating in water-soluble salt, performing oxidation and carbon removal on the templates to obtain template carrying porous salt, and finally performing the processes of vacuum/pressure biological macromolecular solution soaking, vacuum drying, desalting treatment and the like to prepare the honeycomb polymer-based bionic porous scaffold material. The prepared bionic porous scaffold material has a honeycomb porous structure based on the plant tissues, the porosity is 70 to 95 percent, and the aperture is 10 to 160 microns. The preparation methodis widely applied to water-insoluble biological macromolecular materials, and is easy to realize regulation and control of physicochemical, mechanical and biological properties of porous scaffolds. The honeycomb polymer-based bionic porous scaffold material and the preparation method thereof have special significance for realizing regenerative repair of defective tissues of peripheral nerves, muscle tendons, ligaments and the like with longitudinal morphology by using tissue engineering technology, and have broad practical application prospect.

The invention discloses a recombinant bacillus displaying GCRV VP7 proteins on the surface of bacillus subtilis GC5 and a preparation method. The preparation method comprises the following steps: (1) obtaining a present epidemic strain type-II GCRV VP7 nucleotide sequence; (2) separating wide bacillus from the body of a grass carp, determining the wide bacillus to be bacillus subtilis, and naming the wide bacillus as Bacillus subtilis GC5, CCTCC NO: M2014654; (3) constructing a fusion expression recombinant integrated carrier, wherein a vp7 sequence in recombinant plasmids is the nucleotide sequence shown in SEQ ID No. 1; (4) preparing and authenticating recombinant bacillus subtilis, CCTCC NO: M2014655; (5) inducing and authenticating the recombinant bacillus displaying VP7 on the surface. The generation rate of spores is up to 100%, and the recombinant bacillus is simple and convenient to produce, low in cost, and capable of being used as a feed additive; the recombinant bacillus has an intestinal customization capacity, as well as is beneficial to regulating the intestinal bacterial colony balances of animals, improving the body immunocompetence of the animals, and enhancing the nutrition metabolism functions of the animals. The spores are high in stress resistance and easy for large-scale production, as well as solve the problem of instability of GCRV VP7 proteins used as immunizing antigens in extreme environments.

The invention belongs to the field of biotechnology, and discloses a cryopreservation method for adipose tissues. The cryopreservation method includes the steps of preparing adipose tissue cryopreservation protection liquid, treating lipoaspirate, cryopreserving the adipose tissues, performing refrigeration according to a pre-controlled freezing curve after a cryopreservation tube containing the adipose tissues is balanced at the temperature of 4 DEG C, and storing the adipose tissues in a liquid nitrogen tank at the temperature of minus 196 DEG C for a long time. According to the characteristics and application features of the adipose tissues, the activity of the cryopreserved adipose tissues is further improved by reducing the damage of the thermal stress to the adipose tissues, controlling the freezing rate and optimizing cryoprotectants in the cryopreservation process of the adipose tissues; the cryopreservation method has the advantages of stable preservation effect, capability ofeffectively improving the activity of the adipose tissues after re-thawing, and ideal transplantation effect.

The invention relates to the technical field of medicine and particularly relates to an exenatide slow release sustained release microsphere, and a preparation method and a preparation thereof. The exenatide slow release sustained release microsphere comprises the following components in parts by mass: 0.5-10 parts of exenatide, 0.5-10 parts of protecting agent and 80-99 parts of polylactic glycollic acid copolymer, wherein the protecting agent is one of or the combination of more than two of glycine, lysine, arginine or histidine. The exenatide slow release sustained release microsphere adopts the alkali protecting agent which can neutralize local acidation caused by degradation of the polylactic glycollic acid copolymer during release in vitro and degradation in vivo of the microsphere, so that aggregation of polypeptide is reduced and the stability of exenatide is maintained.

The invention discloses a polypeptide, a polypeptide nano drug-loading carrier and a preparation method of the polypeptide and the polypeptide nano drug-loading carrier. The polypeptide has a structural formula of Ac-LLLLLLKKKK-NH2. The preparation method of the polypeptide comprises the steps that various raw materials are added to a polypeptide solid phase synthesizer, and Ac-IIIIKK-NH2 is synthesized from a C-terminal to an N-terminal; and Ac-IIIIKK-NH2 is further prepared to obtain the requried polypeptide. The polypeptide nano drug-loading carrier is of a nanosphere structure capable of being ruptured in an acidic environment, and the nanosphere structure is used for embedding a fat-soluble drug. The preparation method of the polypeptide nano drug-loading carrier comprises the steps that the polypeptide is added to a Hepes solution, and the polypeptide is self-assembled to form the polypeptide nano drug-loading carrier embedding the fat-soluble drug.

The present invention provides new tools useful for controlling the post-translational modifications of recombinant polypeptides. These tools are particular signal peptides allowing the targeting of recombinant polypeptides during their synthesis in a host cell to specific sub-cellular compartments and a specific designing of said recombinant polypeptides within said sub-cellular compartments. These signal peptides are SEQ ID no 1 to SEQ ID no 31 disclosed herein. The present invention relates therefore also to a process for producing a recombinant polypeptide, in particular to a post-translationally modified polypeptide comprising the steps of transfecting or transforming a cell with at least one numleic acid vector encoding a recombinant protein which is the polypeptide before being post-translationally modified or a recombinant protein different to said polypeptide, said recombinant protein comprising a peptide signal according to the present invention; growing the transfected cell; and harvesting the post-translationally modified polypeptide; wherein, when said recombinant protein is different to said polypeptide, the method also comprises a step of transfecting said cell with at least one vector encoding said polypeptide. The present invention allows advantageously, for example, to increase the yield of production of recombinant polypeptides, to prevent immunogenicity if recombinant polypeptides and to obtain therapeutically active recombinant polypeptides that are the exact copy of their natural counterpart. This invention relates particularly to the field of reorientation of plants made pharmaceuticals (PMP).

Methods for use of a multi-arm polyethylene glycol (PEG) modifier in modification of asparaginase. The described multi-arm PEG modifier enhances the subunit interaction of a multimeric protein to maintain the multimeric protein in a polymerized form, thereby improving the stability of the multimeric protein, maintaining the bioactivity of the multimeric protein, and reducing the probability of exposure of the antigen binding site after depolymerization of the subunits, so as to reduce the immunogenicity.

The invention belongs to the technical field of ophthalmology, and relates to a method and a device for assisting in gene transfer by utilizing electroporation. In the method and the device, a double-spoon electrode device is adopted, proper electric stimulation pulse conditions are determined, and green fluorescence protein-containing plasmids are transfected by a retinal pigment epithelial cell layer. The method of the invention has the advantages of directionally controlling the intraocular transfection of genes by using an electric field, simultaneously avoiding the shortcomings of cellular immunogenicity, potential pathogenicity, tumorigenicity and the like caused by viral gene transfer, reducing side injuries to eyeballs by adopting the double-spoon electrode device, simultaneously realizing the transfection of a plurality of plasmids, and compensating for the shortcomings of conventional methods, along with convenient operation, high efficiency, capability of being used as a reference for the gene transfer in ophthalmic researches, and the like.

The invention discloses a preparation method of a biological membrane for dental implantation, which comprises the following steps: taking qualified donor skin as a raw material, removing subcutaneous tissues, and taking a faulted skin graft with a certain thickness; treating the faulted skin graft in a sodium chloride solution, and removing an epidermal layer to obtain a dermal matrix; performing ultrasonic treatment on the dermal matrix in a sodium dodecyl sulfate (SDS) solution and a trypsin solution, crushing and removing cell components; taking the acellular dermal matrix, and soaking the acellular dermal matrix in ethanol to carry out virus inactivation; performing freeze drying to obtain an acellular dermal matrix biological membrane; and packaging the freeze-dried biological membrane, and carrying out irradiation sterilization. According to the invention, an extracellular matrix repairing material can be obtained, the immunogenicity of a heterogeneous material and the degradability of a synthetic collagen membrane are overcome, and an extracellular matrix biological material is provided for dental implantation.