33results about How to "Slow degradation rate" patented technology

The invention discloses a modification method used for the surface of a magnesium alloy stent and contains controlledly degradable magnesium alloy stent surface micro-arc oxidation modification treatment and drug molecule biomimetic deposition; the magnesium alloy stent surface micro-arc oxidation modification treatment is first performed on the surface of magnesium alloy stent substrate to form controlledly degradable microporous ceramic oxide film with high porosity, the thickness of the film is 80-120mu m, the porosity is 20-40%; then drug molecule biomimetic deposition capable of promoting endothelial growth or dissolving thrombus and anticoagulating is performed on the microporous ceramic oxide film and the width of the settled layer is 5-10mu m. The modification of the surface of the magnesium alloy stent of the invention can effectively improve the in vivo biodegradation rate of the stent and the corresponding consistency of the mechanical property thereof, increase the compatibility between the stent and vascular walls, reduce the restenosis rate of blood vessels, lower the incidence of complications of patients and improve the survival rate and the life quality.

The invention relates to a 3D-printed degradable macromolecular scaffold and photo-crosslinked hydrogel composite scaffold. The 3D-printed degradable macromolecular scaffold and photo-crosslinked hydrogel composite scaffold comprises a 3D-printed degradable macromolecular scaffold, wherein the interior of the 3D-printed degradable macromolecular scaffold comprises photo-crosslinked hydrogel with high substitution degree and photo-crosslinked hydrogel with low substitution degree, the photo-crosslinked hydrogel with high substitution degree is crosslinked with the photo-crosslinked hydrogel with low substitution degree, and preferably, a polycaprolactone (PCL) scaffold and methacrylic anhydride gelatin (GelMA) with different substitution degrees are crosslinked and compounded. In the composite scaffold, the 3D-printed degradable macromolecular scaffold has good mechanical properties; the photo-crosslinked hydrogel with high substitution degree has high crosslinking degree, can form a fiber network and micropores, and well supports cells; and the photo-crosslinked hydrogel with low substitution degree has multiple active sites, is beneficial to cell adhesion growth, and can adsorb alarge amount of nutrient solution. Through cooperation of the 3D-printed degradable macromolecular scaffold, the photo-crosslinked hydrogel with high substitution degree and the photo-crosslinked hydrogel with low substitution degree, the composite scaffold is suitable for cell growth and vascularization from an inner layer to an outer layer, and when the composite scaffold is used for medical human body repair, scaffold integration is realized to promote regeneration of new tissues.

The invention discloses a pH-sensitive biodegradable polyurethane-urea material and a preparation method thereof. The polyurethane-urea is pH-sensitive biodegradable polyurethane-urea prepared by mixing dihydroxy-terminal polyether ester with N,N-bis(2-ethoxy) 4-pyridinccarbox amide, carrying out chain expansion by using carbamido-containing diisocyanate and purifying; the polyether ester is usedas a main soft segment, a chain segment containing carbamido and urethane group is used as a hard segment and a pyridine ring is positioned on a side chain. The polyurethane-urea has the characteristics of biodegradability, absorbability of a degradation product, pH sensitivity, high expanding and degrading rate in acidic mediums, as well as basically no expansion and low degrading rate in neutraland alkaline mediums; in addition, the pH sensitivity is not basically affected by temperature and can be applied to the field of controlled release as a drug carrier, and further the drug release rate is controlled according to pH values of different parts of an organism. The hard segment formed by carbamido-containing structure diisocyanate contains dense hydrogen bonds, so that the mechanicalproperty of the material is improved.

The invention relates to a fully degradable high-barrier composite material for flexible packaging, which is mainly prepared by blending the following components in parts by weight: 100 parts of biodegradable matrix resin; 0-30 parts of inorganic filler; 0.1-15 parts of auxiliary agent share. Preferably, the composite material is composed of an inner biodegradable matrix resin and an outer biodegradable matrix resin through double-layer co-extrusion. In parts by weight, the inner biodegradable matrix resin includes: 10-90 parts of PBAT, 10-90 parts of PCL, 0.1-5 parts of auxiliary agents, wherein the total parts by weight of PBAT and PCL is 100 parts; Said outer layer biodegradable matrix resin comprises: 10-90 parts of PBAT, 10-90 parts of PLA, 1-20 parts of inorganic filler, 0.1-8 parts of auxiliary agent; wherein, the total parts by weight of PBAT and PLA is 100 parts; all The inorganic filler is nanometer calcium carbonate or talcum powder.

The invention provides controllable self-crosslinking sulfhydrylated hyaluronic acid-collagen composite hydrogel as well as a preparation method therefore. The composite hydrogel is prepared from hyaluronic acid hydrogel and I-type collagen or II-type collagen; the I-type collagen or II-type collagen is distributed in a three-dimensional crosslinking network structure. The composite hydrogel has rigidity and elasticity, is high in mechanical property, can promote spreading growth of cartilage cells, is favorable for phenotype maintaining for cells, can relieve the shortcomings that an existinggel material for cartilage reparation is easy to shrink and low in cell adhesion, and has an important application value in the field of cartilage injury reparation.

The invention adopts the copolymerization of dibasic fatty acid and dimer acid to prepare the carrier of hydrophilic anti-inflammatory drug and antitumor drug: polyanhydride. Because the polyanhydride material uses a diacid with a long carbon chain as a monomer, the degradation rate is slow and the drug release period is long, so it is suitable for the local sustained release drug treatment of osteomyelitis and solid tumor diseases.

The invention discloses a degradable iron, zinc and magnesium-based gradient composite material based on biological bone healing. A zinc layer and an iron layer are sequentially arranged on the surface of a magnesium matrix, and the thickness or the diameter of the magnesium matrix is 30-90% of bone dimension in the repaired part. The thicknesses of the zinc and iron layers are respectively determined according to the corrosion rates of zinc and iron in an in vitro simulated body fluid. According to the composite material, rigid fixation in early stage is realized to promote bone healing, the composite material is gradually degraded, use of the material with lower rigidity is transited to dynamic fixation, and finally, the material is fully absorbed in vivo to prevent from being taken out in the second operation. Rapid degradation in the non-mechanical bearing later stage is realized, and growth by differentiation of bone cells and ingrowth of blood vessels on the surface of material are induced by hoping to combine the advantages that iron in higher rigidity in the early stage realizes rigid fixation and zinc in lower rigidity in the middle stage realizes dynamic fixation by means of quicker corrosion rate of magnesium. Finally, the composite material is fully absorbed, so as to realize the bone repairing purpose. The composite material disclosed by the invention is applicable to gradient structure designs of internal fixing materials after fracture with change demands on mechanical property with the passage of time.

The invention discloses a biodegradable emamectin benzoate microsphere and a preparation method thereof. The emamectin benzoate is used as an active substance, that is, a core material; the biodegradable The material is a ball-forming material, that is, the wall material, which has the advantages of safety, low toxicity, high efficiency, long-lasting effect and good stability. Compared with the current multi-purpose polymer wall material microcapsules, it has good environmental compatibility, The advantage of good mechanical properties of the material; at the same time, by changing the ratio of polylactic acid and polypropylene carbonate in the wall material, the slow-release performance and particle size of the microspheres can be adjusted and controlled, which not only improves its drug release performance, but also improves Its environmental friendliness reduces the production cost and meets the requirements of pollution-free agricultural production.

The invention relates to a fully-absorbed Mg-Zn-Ag-based amorphous alloy with strong corrosion resistance, high strength and good biocompatibility and a preparation method thereof. The alloy is composed of the following components in the following atomic percentages : Silver 0%‑10%, and the silver content is not 0; zinc 15%‑40%; impurity 0%‑5%; the balance is magnesium. The fully absorbed Mg-Zn-Ag series amorphous alloy of the present invention has excellent mechanical strength and hardness, low gas release, strong corrosion resistance, and can be gradually absorbed by the human body as the damaged tissue heals after being implanted into the human body. It can be absorbed and degraded without secondary surgery, and it is an excellent choice as a degradable implant material in the human body, and has broad application prospects.

The invention discloses a pH sensitive medical polyurethane urea material and a preparation method thereof. The preparation method comprises the following steps: mixing a terminal dihydroxypyridine compound and a double-end hydroxyl polyethylene glycol to obtain polyurethane urea, and dissolving by adding N,N-dimethylformamide, carrying out chain extension in the presence of urea-containing diisocyanate, and purifying to obtain pH-sensitive polyurethane urea, wherein diisocyanate is L-lysine diisocyanate-1,4-butylenediamine-L-lysine diisocyanate. The pyridine group on a side chain of polyurethane urea is Lewis base, which is able to decompose hydrogen bonds in a polyurethane urea network under acidic conditions, resulting in discontinuous volume expansion of material. According to the invention, H<+> is removed under neutral or alkaline conditions, and N on a pyridine ring and NH on carbamate or ureido form a hydrogen bond, approximating a network structure, so that the polyurethane urea molecular chain shrinks and the swelling degree decreases remarkably. Therefore, by controlling the change of the pH of a medium, the degree of swelling of polyurethane urea can be effectively controlled.