39results about How to "Improve cell affinity" patented technology

The invention discloses a multiplex composite engineering scaffold material capable of gradually decomposing bone tissue and a preparation method thereof. The composite scaffold material consists of calcium phosphate bone cement, biological compatible degradable synthetic high polymer and biological compatible degradable natural high polymer, has better mechanical property and gradient degradation characteristic, and can achieve the aim of regenerating and repairing bone tissue defect by implanting a bone growth factor to induce in-vivo stem cells to be differentiated into bone cells, thereby obviously improving initial strength and toughness of the scaffold material, and ensuring enough strength and toughness of the scaffold material during operating and implanting. After compounded with the high polymer material, the scaffold has excellent flexibility, so that the scaffold can be subjected to certain machining, such as cutting and the like.

The invention relates to a chitosan modified alginate hydrogel three-dimensional porous bracket with specific in-vitro degradability and a preparation method thereof. The method comprises the following steps: dissolving sodium alga acid serving as a raw material in phosphate buffer solution; performing amidation reaction of a carboxyl group in the sodium alga acid and an amino group in a cross-linking agent cystamine or dimethyl cystinate under the activation of water-soluble carbodiimide to form a chemically crosslinked hydrogel; performing freeze drying on the hydrogel to obtain a porous bracket material of the hydrogel; and performing surface modification on the porous bracket by using chitosan. In solution of a reducing agent such as cysteine with an appropriate concentration, a disulfide bond in a hydrogel cross-bridge is degraded through a disulfide bond-sulfydryl conversion reaction, so the porous bracket is decomposed and dissolved and disappears. Therefore, the porous bracket can be used as an in-vitro cell culture template material. The hydrogel porous bracket researched by the invention has the characteristics of simple preparation, rich raw material source, low cost and availability. Various physiochemical performances, mechanical strength, degradation rate and surface properties of the bracket material are controllable within a large range.

The invention relates to a novel double-layered composite transmitting tissue regeneration membrane and a preparation method thereof. The double-layered composite transmitting tissue regeneration membrane consists of a PLGA/hydroxyapatite nonporous dense membrane on the outer layer and a PLGA/woolen keratin electrostatic spinning porous membrane on the inner layer. By means of a solvent casting method and a high-voltage electrostatic spinning method, the synthetic material PLGA is combined with the natural component woolen keratin and the inorganic component hydroxyapatite to form the composite material which supplement each other with respective advantages, thereby forming the PLGA/hydroxyapatite/woolen keratin double-layered composite transmitting tissue regeneration membrane. The double-layered composite transmitting tissue regeneration membrane disclosed by the invention is simple in preparation method and moderate in membrane forming conditions, has a good cell biocompatibility, conforms to the requirement of application in the living organism, and has a good application prospect as a novel transmitting tissue regeneration membrane.

The invention provides a method for preparing flamazine/bacterial cellulose composite wound dressing, which comprises the following steps of: performing pretreatment and purification treatment on a bacterial cellulose membrane to obtain purified bacterial cellulose; preparing flamazine suspension with the granularity of 50 to 5,000 nm under dark condition; reacting the bacterial cellulose membrane with the flamazine suspension to form a flamazine/bacterial cellulose composite membrane; and performing drying treatment to obtain a dry flamazine/bacterial cellulose composite membrane, or performing extruding dehydration to obtain a wet flamazine/bacterial cellulose composite membrane with different water content values to prepare the flamazine/bacterial cellulose composite wound dressing. The prepared flamazine/bacterial cellulose composite wound dressing has high mechanical performance, high antibacterial property, and high water and air permeability or good drainage and moisture absorption effects, can promote the drying, scabbing and healing of wound, and is used for preventing and treating the secondary wound infection of second-degree and third-degree burn or scald.

A diamine modified polylactic acid, its preparing process and its application in preparing the biodegradable medical materials, especially the tissue engineering material, are disclosed. Its advantages are excellent hydrophilicity and neutral degradation.

The invention discloses a copolymer of fibroin and a poly D,L-lactic acid. The molecular weight of the copolymer having the structure is 5,000 to 180,000, and the mass ratio of the fibroin chain segment and the poly L-lactic acid chain segment is 0.5/99.5-99/0.5. The invention also discloses a solid phase polymerization preparation method thereof, the application thereof in biomedical materials, nano material thereof and a preparation method of nano materials. Copolymer of fibroin and poly D,L-lactic acid is prepared by adopting melt ring opening polymerization, and solvent is not used in the synthesis technique; therefore, the invention has the advantages that the process is simple, and the product cost is low. Through the invention, copolymer of fibroin and poly D,L-lactic acid with different number average molecular weight can be prepared. Copolymer of fibroin and poly D,L-lactic acid prepared by the invention can improve the hydrophilicity, the biocompatibility and the cellualar affinity of lactic acid material and control the degradation speed of the material.

The invention discloses an absorbable medical suture line with good mechanical performance. The absorbable medical suture line comprises, by weight, 100-120 parts of modified polylactic acid, 20-40 parts of polyglycollide, 4-6 parts of sorbitol, 3-5 parts of methyl methacrylate and 5-6 parts of cassia oil. The preparation method of the modified polylactic acid includes: in ice-bath, adding chitosan into perchloric acid, well mixing, dripping sorbic acid chloride, stirring, cooling, preserving heat and purifying to obtain modified chitosan; taking polyethylene glycol, feeding inert gas, heating, preserving heat until the polyethylene glycol melt, adding stannous chloride and lactide, well mixing, heating, preserving heat and stirring, and purifying to obtain intermediate material; dissolving the modified chitosan in mixed solvent, adding triethylamine, well mixing, heating, refluxing, adding the intermediate material, well mixing, continuing refluxing, purifying and drying to obtain the modified polylactic acid.

The invention discloses a nano bone biomimetic material containing tussah silk fibroin, which is prepared from hydroxyapatite, tussah silk fibroin and chitosan, wherein the mass ratio of the hydroxyapatite to the tussah silk fibroin to the chitosan is 1:(0.1-0.5):(0.1-0.5). The porous nano bone biomimetic material containing tussah silk fibroin obtained by the invention has a big amount of intercommunicated micropores of the nano level, and has a higher porosity; the components containing the bone biomimetic material have good biological compatibility and structurally simulate the bone structure; and the hydroxyapatite/tussah silk fibroin nano compound particles are of the nano level and form strong binding force with the chitosan. The bone biomimetic material disclosed by the invention has good mechanical property, good formability and reasonable porosity, and can be used as an implanted degradable bone repair material.

The invention discloses a copolymer of fibroin and a poly L-lactic acid. The molecular weight of the copolymer having the structure is 5,000-200,000, and the mass ratio of the fibroin chain segment and the poly L-lactic acid chain segment is 1/99-99/1. The invention also discloses a solid phase polymerization preparation method thereof and the application thereof in biomedical materials. The invention adopts the method of direct polymerization, the copolymer of fibroin and the poly L-lactic acid is prepared through main body melt/solid phase polymerization, and solvent is not used in the synthesis technique; therefore, the invention has the advantages that the process is simple, the product cost is low, the production cycle is short, and no pollution is generated. Through the invention, copolymer of fibroin and poly L-lactic acid with different number average molecular weight can be prepared, with the molecular weight of 5,000-200,000. Copolymer of fibroin and poly L-lactic acid prepared through the invention can improve the hydrophilicity, the biocompatibility and the cellualar affinity of lactic acid material and control the degradation speed of the material.

The invention discloses a preparation method of an absorbable medical suture with good tensile strength. Inert gas is fed into ethylene glycol monomethyl ether, the ethylene glycol monomethyl ether is heated, the temperature is kept until the ethylene glycol monomethyl ether is molten, zinc lactate and lactide are added, the mixture is evenly mixed, heated, kept at the temperature, stirred and purified, and an intermediate material is obtained; carboxymethyl chitosan is added to water for dissolution, the intermediate material and stannous chloride are added and evenly mixed, inert gas is fed, the mixture is heated, kept at the temperature and purified, and modified chitosan is obtained; the modified chitosan, diisopropyl carbodiimide, glucose and cassia oil are evenly mixed, and the absorbable medical suture with the good tensile strength is prepared with a melt spinning method. The prepared suture is good in tensile strength, easy to knot, high in mechanical performance and well compatible with biological tissue, and cells adhere and reproduce on the prepared suture easily.

The invention provides a preparation method of ethylenediamine and RGD polypeptide modified MPLGA with high anhydride content. With D,L-lactide, glycolide and maleic anhydride being raw materials, stannous octoate being a catalyst and benzoyl peroxide being an initiator, the maleic polylactide glycolide anhydride (MPLGA) with the high anhydride content is prepared through polymerization under vacuum conditions; a trichloromethane solution of ethylenediamine is added into a trichloromethane solution of MPLGA under stirring conditions, the mixture is kept warm for 5-10 minutes at the temperature lower than 10DEG C and reacts for 30-60 minutes at room temperature, the product is dropwise added into an excessive solvent to precipitate and be separated out, and polymer (EMPLGA) solids of ethylenediamine modified MPLGA are obtained; the EMPLGA is dissolved in tetrahydrofuran, a coupling agent, namely N,N-dicyclohexylcarbodiimide, is added, the pH value of the solution is adjusted to range from 8 to 9, stirring is carried out, a tetrahydrofuran solution of RGD is dropwise added, the mixture reacts for 24 hours at the temperature of 0 DEG C and then is filtered, and the polypeptide modified RGD-EMPLGA solids are obtained after the product is frozen and dried. The prepared product has better hydrophilia, cell affinity and a controllable degradation property.

The invention relates to a method for preparing a RGD-polypeptide grafted poly(maleidohexanediamine acid-D,L-lactic acid)/beta-TCP composite material. According to the method, maleidohexanediamine acid and RGD-polypeptide are adopted to modify polylactic acid, then cell affinity of the polylactic acid can be improved, and the polylactic acid is beneficial to adhesive growth of cells; hexamethylendiamine has the main function of controlling accumulation of acidity in the degradation process, and sterile necrosis of implanted tissue can be prevented; maleidohexanediamine acid is firstly synthesized, a polylactic acid side chain is further introduced, then the reaction times of polylactic acid can be reduced, molecular weight reduction of the polylactic acid can be avoided, and the mechanicalproperties of the composite material can be ensured; calcium and phosphorous ions generated from degradation of beta-TCP as a biodegradable material with good biocompatibility are also essential substances for growth of bone tissue, nerve cells and the like.