82results about How to "Maintain biological properties" patented technology

The present invention describes a bioconjugation strategy and compounds that are useful therein in which a fluorescent signal is produced when two molecular or supramolecular entities are linked by chemoselective combination of one linker having an azido or halide substituent group with another linker having a cyano or an alkyne substituent group. A kit is also provided.

The invention relates to a serum-free culture medium for mesenchymal stem cells and application thereof. The serum-free culture medium comprises a basal culture medium and additive components. The additive components comprise the following components: 2'-Deoxyadenosine, 2'-Deoxycytidine-HCl, 2'-Deoxyguanosine, L-glutamine, human serum albumin, recombinant human transferrin, recombinant human insulin, rhPDGF-BB, rhFGF-b, rhTGF-beta1, rhEGF, sodium selenate and hydrocortisone. The serum-free culture medium disclosed by the invention does not contain animal-derived heterologous component such asbovine serum, and can effectively replace serum to culture bone marrow mesenchymal stem cells; and due to the synergistic effect of the additive components, the culture medium has the advantages of shortening cell cycle, rapid proliferation and good cell consistency while culturing bone marrow mesenchymal stem cells, and can effectively maintain the molecular characteristics and differentiation potential of the bone marrow mesenchymal stem cells. The bone marrow mesenchymal stem cells obtained by the culture medium are suitable for further scientific research and clinical application research.

The invention relates to a multi-enzyme system for separating different tissues-derived primary culture cells of a normal human and a mammal. The system comprises a plurality of 0.0125 to 0.125 weight percent of trypsin, 0.02 to 0.2 weight percent of collagenase I-IV, 0.0015 to 0.015 weight percent of hyaluronidase, 0.02 to 0.2 weight percent of neutral protease, 0.0015 to 0.015 weight percent of deoxyribonuclease I, 1 to 10 U / ml papain, 0.015 to 0.15 weight percent of pronase, 5 to 50 U / ml elastase and 0.01 to 0.1 weight percent of separase. The invention also relates to the application of the multi-enzyme system and a kit formed by the multi-enzyme system. The multi-enzyme system of the invention has the characteristics of reasonable design and capacity of separating the different tissues-derived primary culture cells of the normal human and the mammal highly specifically and highly sensitively; and the separated primary culture cells have the characteristics of high survival rate, high purity, easy cryopreservation and recovery, can be used for medicament experimental evaluation, medicament toxicity test and medicament therapeutic judgment, and are suitable for large-scale popularization and application.

The invention relates to a selective cholesteryl chitosan nano particle and a preparation method thereof. The preparation method comprises the following steps of: preparing cholesteryl succinate (CHS) and phthaloyl chitosan (PHCS) by using cholesterol, succinic anhydride, phthalic anhydride and chitosan as raw materials and then reacting the CHS and the PHCS to prepare the cholesteryl chitosan nano particle, wherein the particle size is 100-200 nm, the molar ratio of the cholesterol to the succinic anhydride is 1-30:3-90, and the molar ratio of the chitosan to the phthalic anhydride is 1-60:3-180. An amphiphilic polymer obtained with the preparation method comprises a hydrophilic polysaccharide skeleton and a hydrophobic cholesterol branched chain and can automatically gather in a water medium to form the nano particle with a nucleus-shell type structure; and the nano particle has positive charge, is beneficial to the entrapment of hydrophobic medicaments, albumen and DNA, and has the advantages of simple preparation method, good repeatability, easy industrial production, high medicament-carrying efficiency and favorable slow-releasing effect.

The invention relates to a mesenchymal stem cells serum-free culture medium. The serum-free culture medium comprises a basal culture medium and an additive component, wherein the additive component comprises the following components: rhEGF, rhVEGF, rhPDGF-BB, rhFGF-b, rhTGF-beta1, human serum albumin, recombinant deferritin, a recombinant human insulin growth factor and hydrocortisone. The invention also provides an application of the mesenchymal stem cell serum-free medium. The composition is clear and stable; the instability of serum culture is eliminated, and meanwhile, all factors have thesynergistic effect, the umbilical cord mesenchymal stem cells can be efficiently amplified, the cell cycle is shortened, the proliferation is rapid, the yield of three generations of cultured cells reaches 1.5 times or more of that of serum culture, the cell consistency is good, and the biological characteristics and differentiation potential of the umbilical cord mesenchymal stem cells can be efficiently maintained due to the synergistic effect of all factors.

The invention discloses a separation and culture method of adipose-derived stem cells. The method comprises the following steps of (1) collecting adipose tissues; (2) adding collagenase into the adipose tissues obtained in the step (1) for digestion to obtain the adipose-derived stem cells; (3) enriching the adipose-derived stem cells obtained in the step (2); and (4) conducting purification and subculture on the adipose-derived stem cells obtained in the step (3). In the step (2), an animo acid sequence of the collagenase is as shown in Seq ID No.5; a volume percent fraction of the adipose tissues in a digestion system is 40-60%; the content of the collagenase in the digestion system is 0.20-0.30 g / L; and digestion time is 15-30 min. The method has the advantages that the dosage of the collagenase is little, and the separation efficiency of the adipose-derived stem cells is high, so that the method has important values for scientific research and large-scale separation and culture ofadipose-derived stem cells.

The invention relates to an adhesive amniotic membrane, which is a double layer or multi-layer adhesive amniotic membrane bonded with amniotic membrane and fibrin albumen glue. The preparing method comprises: bonding the fresh amniotic membrane of epithelium removed with fresh amniotic membrane without removing epithelium by using fibrin albumen glue; or condensing the amniotic membrane immersing in the glycerol, and then bonding the fresh amniotic membrane of epithelium removed with fresh amniotic membrane without removing epithelium by using fibrin albumen glue; or bonding with the fresh amniotic membrane without removing epithelium by using fibrin albumen glue; finally putting the bonded adhesive amniotic membrane into pure glycerol under 0-6 Deg C for closed and sterile conservation. The product not only maintains the biological property and various biological activity of the amniotic membrane, but also the increases the clinical treating effect distinctively. The preparing process id simple and economical, the conservation time is as long as one year and with a high biological safety, which is facilitate for clinical spead. The product can be widely used in tissue engineering rebuilding and restoring, traumatology department, ulcerative tissue restoring, burn, scald biological dressing, plastics for eye rebuilding operation, and etc.

The invention belongs to the technical field of crop breeding, and provides an isolation and purification method for Chenopodium quinoa, and aims at solving the problems that Chenopodium quinoa growsmildew easily, the grains are not full and the Chenopodium quinoa is sterile at high temperature. A nonwoven fabric material is made into an isolation bag with a closed bottom, an opening at the upperend of the isolation bag is provided with a contraction rope, and two sides of the isolation bag are provided with cellophane observation windows; during the florescence of Chenopodium quinoa, branches and leaves were removed from top to bottom, and 2-3 cm of a trunk is exposed; the top end is sleeved with the isolation bag; after the top end is sleeved for 15-20 days, main ears fully fill the bag, the isolation bag is removed, pruning is performed downwards from the top end to remove branches and leaves and expose 2-3 cm of the trunk, secondary sleeving is performed; after the bag is changed, the bag is removed according to the flowering period, the single plant with the main ears sleeved are harvested in the mature period. The structure and method have no influence on the grain fullnessand the yield of Chenopodium quinoa, and can meet the requirements of subsequent research on the seed quantity. The problems that the inflorescences easily grow mildew during isolation and purification sleeving so that the seed setting amount is low, the grains are not full and sterility is caused due to the high temperature are solved.