42results about How to "Maintain biological function" patented technology

The invention belongs to the technical field of biology, in particular to a preparation method of full-length Fas-associated death domain (FADD) protein, which utilizes a recombinant DNA technique to express and prepare the full-length FADD protein which has good stability, high yield, the same high-level structure as a wild FADD and activity for inducing cell apoptosis, and the preparation method has more convenient and faster separation and purification process and high yield. The full-length FADD protein can be applied to prepare a medicament for inducing the cell apoptosis and treat diseases such as tumors, rheumatoid arthritis, and the like. The invention also provides an expression method for expressing the full-length FADD protein in a prokaryotic expression system, which can effectively improve the yield of the full-length FADD protein.

The invention discloses a magnesium-based metal material conversion film and a preparation method thereof. The conversion film is mainly composed of a polyphenol organic conversion layer on the surface of a magnesium base material. The preparation method is as follows: (1) pretreatment of the magnesium metal substrate, followed by sandpaper polishing, NaOH activation, dopamine soaking, etc.; (2) cleaning the pretreated sample with deionized water at room temperature, and immersing it in polyphenolic compound and magnesium After reacting in the mixed salt solution for 2-15 minutes, ultrasonically clean with ethanol to complete a reaction cycle; repeat the reaction cycle 3-5 times to obtain a magnesium-based metal material conversion film. The conversion film prepared by the preparation method of the present invention can effectively solve the technical problems of low structural stability and poor long-term corrosion resistance of the conversion film, and the polyphenolic compound helps to capture excess active oxygen in the body and protect the body from attacked by reactive oxygen species. The conversion coating can be applied to the surface modification research of fully degradable magnesium-based metal cardiovascular stents and fully degradable magnesium-based orthopedic filling materials.

The invention relates to a method for culturing and freezing amniotic mesenchymal stem cells. The culturing method includes amniotic membrane tissue separation, amniotic mesenchymal stem cell separation, P0 generation amniotic mesenchymal stem cell culture and expansion culture. The culture method of amniotic mesenchymal stem cells of the present invention, in the separation stage of amniotic mesenchymal stem cells, adopts a special mixed enzyme digestive solution system (final concentration of each component in the digestive solution: 1.5-2U / mL neutral protease, 0.5mg / mL deoxyribonuclease I and 1mg / mL collagenase IV) for digestion, can more effectively separate amniotic mesenchymal stem cells from amniotic tissue, and then significantly improve the yield of P0 generation cells. The present invention adopts one-step digestion Compared with the traditional two-step digestion method, the operation is more convenient, and the cultured amniotic mesenchymal stem cells have good activity, high yield, high purity, and good repeatability.

The invention discloses a low-temperature preserved solid culture medium used for a tissue engineering skin model and a preservation method of the low-temperature preserved solid culture medium. The low-temperature preserved solid culture medium is prepared by the following steps: adding a low-temperature protection agent into a common culture medium for epidermis cells to prepare a basic culture solution; and mixing the basic culture solution with agarose gel and condensing to form the solid culture medium suitable for the skin model. The tissue engineering skin model is embedded into the culture medium, is preserved at 4-8 DEG C for 24-72 hours, and then is resuscitated by a common epidermis cell culture solution. The solid culture medium can be used for reducing tissue activity reduction and structure damages of cells and skin tissues, caused by a low-temperature preservation condition, to the greatest extent.

The invention relates to a polyurethane material subjected to photo-induced graft surface modification by fungi polysaccharide and a preparation method thereof. The polyurethane material subjected to photo-induced graft surface modification by the fungi polysaccharide is characterized by consisting of a base material and a modification layer; the base material consists of a common commercial polyurethane material; and the modification layer is formed by performing photo-induced graft surface modification on the surface of the base material by using fungi polysaccharide, namely lentinan. The surface of the polyurethane material subjected to photo-induced graft surface modification by the fungi polysaccharide has high antibacterial activity, and blood compatibility, so that as the artificial transplant material implanted into a human body, and the biocompatible medical material of an artificial organ and device, the polyurethane material has a wide application range, and the preparationmethod of the material is simple, high in reaction speed, and low in cost and is easy to control.

The invention provides a compound active amnion material, a preparation method and application thereof and a compound active amnion uterine cavity repair stent. The preparation method comprises the following steps: (1) providing a collagen sponge prepare liquid or a compound collagen sponge prepare liquid; (2) providing an amnion with both an epithelial layer and a basement membrane; (3) pouring and coating the prepared prepare liquid on the basement membrane of the amnion to enable the basement membrane and the prepare liquid to be subject to crosslinking, and then preparing the compound active amnion material through freeze drying. The compound active amnion material not only keeps the complete structure and the due biological function of the amnion but also endow the amnion with a certain rigidity, so that the compound active amnion material has stronger maneuverability in application after TCRA (Transcervical Resection Of Adhesions) operation; the compound active amnion uterine cavity repair stent integrates the compound active amnion material and a saccule at the front end of a pipe body, the saccule expands under the action of an external force to push out the compound active amnion material, and then the compound active amnion material is successfully attached to the inner wall of the uterine cavity; the stent is convenient to take out and prevents secondary damage.