36results about How to "Adjust the degradation rate" patented technology

The invention relates to drug slow-release microparticles, in particular to triptorelin sustained-release microparticles and a preparation method thereof. The composition includes the following components by weight percentage: 0.5%-20% of triptorelin, 79%-99% of PLGA, and 0.1%-1% of poloxamer. The preparation method of the above-mentioned triptorelin sustained-release microparticles of the present invention comprises mixing each component and sending it into a hot-melt extruder, where heating and melting, extrusion and low-temperature pulverization are carried out. The praline sustained-release microparticles of the present invention have good shape, high encapsulation efficiency of the microparticles, good drug loading capacity and stable release. The synthesis process is simple, the product itself is non-toxic, and the product after degradation is non-toxic and stable in quality.

The invention relates to a biomedical magnesium alloy with dual corrosion resistance and a preparation method thereof, which is composed of a biomagnesium alloy substrate, an inner layer of graphene and an outer layer of tin dioxide uniformly distributed on the grain boundaries of the magnesium alloy, and uses graphene and The double-layer structure of tin dioxide provides double resistance, thereby improving the degradation resistance of magnesium alloys. First, the magnesium alloy powder is immersed in NaOH solution for etching to form negatively charged hydroxyl groups on the surface of the particles; then immersed in PDDA solution to positively charge the surface of the particles; Then immerse in the graphene oxide solution to obtain the PDDA-graphene oxide coating layer, and then immerse in the weakly alkaline tin chloride aqueous solution to obtain the magnesium alloy powder wrapped by the graphene-tin dioxide double-layer structure; finally, under the protective atmosphere, pass Preparation of biomedical magnesium alloy with excellent corrosion resistance by selective laser melting. The present invention utilizes the graphene-tin dioxide double-layer structure to wrap the magnesium alloy crystal grains, and serves as a double-layer protective shield to isolate the contact between the magnesium alloy and the corrosive medium, thereby improving the corrosion resistance.

The invention relates to a composite simulated enzyme gel for degrading organic pollutants and its preparation method and application. The method comprises the following steps: (1) dissolving amino acid in deionized water to form an amino acid solution, adding acid to adjust pH=6.5 -7.5, add an equal volume of copper ion solution drop by drop, continue to adjust the pH=6.5-7.5 and stir, after washing several times, freeze-dry the product to obtain simulated enzyme; Add simulated enzymes to the mixture to obtain a mixed solution; adjust pH=3.5-7.5 after stirring and dissolving, and age to obtain a composite simulated enzyme gel containing mesoporous or micropores for degrading organic pollutants, and used to degrade phenols and / or phenols in the environment or dye-like organic pollutants. Compared with the prior art, the present invention controls the speed of enzyme degradation by adjusting the pore size without causing additional pollution to the environment, so as to achieve long-term, stable and efficient degradation effects, and has a good application prospect.

The present invention provides a biodegradable zinc (or zinc alloy) and porous biphase calcium phosphate composite material and a preparation method thereof. The composite material comprises porous biphase calcium phosphate and zinc or a zinc alloy, wherein the zinc or the zinc alloy is arranged in the porous biphase calcium phosphate through suction casting, the porosity of the porous biphase calcium phosphate is 60-95%, the HA content is 10-70%, the beta-TCP content is 30-90%, and the zinc or the zinc alloy is zinc, a zinc-magnesium alloy, a zinc-yttrium alloy, a zinc-calcium alloy, a zinc-magnesium-manganese alloy, a zinc-magnesium-calcium alloy or a zinc-magnesium-yttrium alloy. The composite material is non-porous at the initial stage, and has good mechanical stability and good mechanical strength; after the composite material is implanted a certain time, the composite material is degraded, and the portion which is degraded slowly maintains the mutually-penetrated porous structure so as to prompt the bone to grow in the structure; and the composite material is gradually degraded along with the gradual growth of the bone in the structure, and the composite material is completely degraded when the bone is healed, such that the good coordination of the biodegradability of the composite material and the osteoinductive is provided.

The invention discloses a long-acting physical cuttlefish marking device based on an endoskeleton cuttlebone. The long-acting physical cuttlefish marking device comprises an inner housing and a radio frequency chip arranged in the inner housing, wherein the inner housing is connected with an outer housing through a supporting rod and a connecting sleeve, diluted heat-conducting silicone grease is filled between the inner housing and the outer housing, a threaded plug is connected in the connecting sleeve, the outer side of the threaded plug is filled with a sealant, a supporting ring is arranged between the surface of the middle of the inner housing and the outer housing, a spherical hole is formed in the supporting ring, and a balancing rod is arranged in the spherical hole. The long-acting physical cuttlefish marking device has the advantages that a positioner is arranged on the connecting sleeve and real-time positioning and tracing to marked cuttlefishes can be kept. The device is simple in structure, easy to manufacture, convenient to mark, low in cost and suitable for the research of a large individual quantity, the service life of the chip is long, and periodical research can be conducted on marker lives. The device has excellent biocompatibility, does not affect normal growth of cuttlefishes and has excellent corrosion resistant performance.

The invention discloses a method for preparing a corrosion-resistant bio-magnesium alloy, which comprises the following steps: (1) placing a specific ratio of calcium oxide powder and bio-magnesium alloy powder in a ball mill, and ball milling to obtain a mixed powder under a protective atmosphere; ( 2) Using the above mixed powder as raw material, under a protective atmosphere, the corrosion-resistant bio-magnesium alloy was prepared by selective laser melting; during the preparation process, the laser power was controlled at 60-90W, the scanning speed was 100-500mm / min, and the spot diameter was 40 -100 μm. In the present invention, calcium oxide is added to the bio-magnesium alloy through laser selective melting to generate Mg / Al-Ca phase with smaller volume, and utilizes the characteristics of rapid solidification speed of laser selective area to refine the volume of the second Mg / Al-Ca phase at the same time Improve its continuity, and then wrap the magnesium alloy grains to form a continuous second-phase protective layer to prevent the erosion of body fluids.

The invention discloses a preparation method of cohesive composite microsphere porous scaffolds, which comprises the steps as follows: 1) nano hydroxyapatite and polylactic acid are adopted as raw materials, and composite microspheres are obtained by ultrasonic blending, suspension balling, solvent volatilization and freeze drying; and 2) the composite microspheres are subjected to grain size screening, mold feeding, air flow smoothening, polylactic acid solution dropwise adding and cohesion, solvent volatilization by air flow, vacuum heat insulation and sintering, demoulding and washing so asto obtain the porous scaffolds. The preparation method has simple process; the porosity factor of the composite microsphere is high; the aperture of the scaffold and the porosity factor can be adjusted; the moulding of the scaffold is convenient; the shape designability is strong; other cohesive phases are not introduced; and the heating time at high temperature is short. The prepared scaffold has good three-dimensional interlocking pores, good mechanical property and biocompatibility, can meet the demands of tissue engineering scaffold materials, and has potential and wide practical value inthe field of tissue repair in bone tissue engineering.

The invention relates to the technical field of biodegradable materials, specifically to a preparation method for a fully-synthetic biodegradable high-strength hemostatic foam applicable to hemostasisof cavities like ears and noses of human or animals. The biodegradable high-strength polyether ester type polyurethane urea foam is prepared from a polyether ester type polyurethane urea material through freeze-molding, wherein the polyether ester type polyurethane urea is prepared through chain extension of dihydroxy-terminal triblock prepolymer by using diisocyanate with a urea structure as a chain extender; the polyurethane urea material has a number average molecular weight of 1.1 x 105 to 1.8 x 105 and a dispersion coefficient of 1.18 to 1.51; and the diisocyanate chain extender containing the urea structure is selected from the group consisting of L-lysine diisocyanate-1,4-butadiamine-L-lysine diisocyanate and L-lysine diisocyanate-1,6-hexane diamine-L-lysine diisocyanate.

The invention discloses a self-thickening bone wound hemostatic gel and its preparation method and application. The gel includes a zwitterion-polysaccharide polymer brush, a solvent matrix, and blood coagulation factor components. First, the zwitterion-polysaccharide polymer brush is prepared , then, the zwitterionic-polysaccharide polymer brush is mixed with the solvent base, stirred to obtain a pre-gel, and finally, blood coagulation factors are added to the pre-gel, and stirred to obtain a self-thickening bone wound hemostatic gel, the present invention The bone wound hemostatic gel has simple components, does not need to add thickeners, excipients and other components, and has a good hemostatic effect, is easy to absorb, and does not affect wound healing.

The invention discloses biological magnesium alloy with a corrosion resistant function. The biological magnesium alloy is prepared from a biological magnesium alloy matrix and graphene oxide, whereinthe graphene oxide is distributed on the grain boundary of the biological magnesium alloy matrix, and the graphene oxide wraps biological magnesium alloy grains so as to form a second phase of a nanohoneycomb structure. The invention further discloses a preparation method. The preparation method comprises the following steps of (1) respectively putting GO powder and biological magnesium alloy powder in absolute ethyl alcohol according to the design proportion for ultrasonic agitation so as to obtain a GO suspension and a biological magnesium alloy suspension; (2) slowly adding the GO suspension to the biological magnesium alloy suspension, continuing to perform ultrasonic agitation so as to obtain a mixed suspension, and performing vacuum filtration and drying treatment on the mixed suspension so as to obtain mixed powder with uniform dispersion; and (3) performing selective laser melting on the mixed powder in the protective atmosphere so as to prepare the biological magnesium alloywith the corrosion resistant function. According to the biological magnesium alloy with the corrosion resistant function, the second phase of the nano honeycomb structure constructed by utilizing GO can be used as a shield so as to isolate the biological magnesium alloy from body fluid, so that a galvanic corrosion effect of a conventional second phase is avoided, and the corrosion resistance is improved.