159 results about "Poly-L-lactide" patented technology

An acid fracturing method is provided in which the acid is generated in the fracture by hydrolysis of a solid acid-precursor selected from one or more than one of lactide, glycolide, polylactic acid, polyglycolic acid, a copolymer of polylactic acid and polyglycolic acid, a copolymer of glycolic acid with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, and a copolymer of lactic acid with other hydroxy-, carboxylic acid or hydroxycarboxylic acid-containing moieties. The solid acid-precursor may be mixed with a solid acid-reactive material to accelerate the hydrolysis and/or coated to slow the hydrolysis. Water-soluble liquid compounds are also given that accelerate the hydrolysis. The method ensures that the acid contacts fracture faces far from the wellbore.

A new embolic agent, bioabsorbable polymeric material (BPM) is incorporated to a Guglielmi detachable coil (GDC) to improve long-term anatomic results in the endovascular treatment of intracranial aneurysms. The embolic agent, comprised at least in part of at least one biocompatible and bioabsorbable polymer and growth factors, is carried by hybrid bioactive coils and is used to accelerate histopathologic transformation of unorganized clot into fibrous connective tissue in experimental aneurysms. An endovascular cellular manipulation and inflammatory response are elicited from implantation in a vascular compartment or any intraluminal location. Thrombogenicity of the biocompatible and bioabsorbable polymer is controlled by the composition of the polymer. The coil further is comprised at least in part of a growth factor or more particularly a vascular endothelial growth factor, a basic fibroblast growth factor or other growth factors. The biocompatible and bioabsorbable polymer is in the illustrated embodiment at least one polymer selected from the group consisting of polyglycolic acid, poly~glycolic acid/poly-L-lactic acid copolymers, polycaprolactive, polyhydroxybutyrate/hydroxyvalerate copolymers, poly-L-lactide. Polydioxanone, polycarbonates, and polyanhydrides.

The present invention comprises a stent forming a plurality of meandering elements comprising a blend formed from a polymer. The polymer comprises poly-L-lactide, poly-D-lactide or mixtures thereof and a copolymer moiety comprising poly-L-lactide or poly-D-lactide linked with ε-caprolactone or trimethylcarbonate. The poly-L-lactide or poly-D-lactide sequence in the copolymer moiety is random with respect to the distribution of ε-caprolactone or trimethylcarbonate and the copolymer moiety molecular weight ranges from about 1.2 IV to about 4.8 IV. The meandering elements may be stretched to a modulus ranging from about 250000 PSI to about 550,000 PSI, one segment of the meandering element has a decreased cross-sectional area and may have a wide-angle X-ray scattering (WAXS) 2θ values of ranging from about 1 to about 35. In various embodiment, two, three or n segments of the meandering element have a decreased cross-sectional area and may also have a wide-angle X-ray scattering (WAXS) 2θ values of ranging from about 1 to about 35 after stretching. In another embodiment, all segments of the meandering element have a decreased cross-sectional area and may also have a wide-angle X-ray scattering (WAXS) 2θ values of ranging from about 1 to about 35 after stretching. The meandering element may comprise a helical winding, a circumferential winding or stent ringlet. The properties of the bioabsorbable polymers allow for both crimping and expansion of the stent. The crystal properties of the bioabsorbable polymers may change during crimping and/or expansion allowing for improved mechanical properties such as tensile strength and slower degradation kinetics.

The present invention discloses a super-tough high heat resistant polylactic acid / elastomer blended material or an article, which is prepared by melting and blending or further processing and molding the following components: 75 to 99 parts of poly-L-lactic acid or poly-D-lactic acid, 1 to 25 parts of third component poly-D-lactic acid or poly-L-lactic acid, and elastomer accounting to 5-30wt% of the total amount of the polylactic acid, the crystallinity of the obtained blended material or article is 43-53%, the heat resistant temperature is 113.5-140.5 DEG C, and notch impact strength is 20.5-93.3kJ / m<2>. By use of the characteristic of easy stereocomplexing of chiral polylactic acid molecules, stereocomplex crystals are formed in suit in a melt from small amount of third component molecular chains and matrix molecular chains, on the one hand the stereocomplex crystals can be used as a rheology modifier to change the dispersion state of the elastomer in a matrix to improve the toughening efficiency of the elastomer on the matrix, and on the other hand the stereocomplex crystals can be used as a nucleating agent to greatly accelerate matrix crystallization. The method is not only ingenious in design, but also provides an effective and simple way for the development of super-tough high heat-resistant polylactic acid blended materials or articles.

The bioabsorbable polymers and compositions of the present invention may be formed into medical devices such as stents that can be crimped onto a catheter system for delivery into a blood vessel. The properties of the bioabsorbable polymers allow for both crimping and expansion of the stent. The crystal properties of the bioabsorbable polymers may change during crimping and/or expansion allowing for improved mechanical properties such as tensile strength and slower degradation kinetics. Typically, bioabsorbable polymers comprise aliphatic polyesters based on lactide backbone such as poly L-lactide, poly D-lactide, poly D,L-lactide, mesolactide, glycolides, lactones, as homopolymers or copolymers, as well as formed in copolymer moieties with co-monomers such as, trimethylene carbonate (TMC) or ε-caprolactone (ECL).

The invention discloses a method for continuously refining L-lactide from crude L-lactide, which comprises the following steps of: firstly, performing at least once lightness removal to the crude L-lactide by using a lightness-removing column, sending melted crude L-lactide into the middle of the lightness-removing column, refluxing and separating as well as distilling the crude L-lactide in the lightness-removing column, condensing vapor distillate at the upper end of the lightness-removing column for removing water, L-lactate and meso-lactide; secondly, enabling column bottom liquid to enter a reboiler for vaporization and then enter into the column, performing at least once rectification to the left column bottom liquid through a treating column after cooling, wherein the lower end of the lightness-removing column mainly has high-boiling point distillate liquid comprising the L-lactide and lactate oligomer; and when in rectification, refluxing and separating the column bottom liquid of the lightness-removing column to obtain a refined L-lactide; refining column bottom flow to obtain concentrated lactate oligomer. The L-lactide purified by the method can be directly used in the polymerization of poly L-lactate, thereby lowering the purifying cost of the L-lactide, increasing the yield, and being environmental friendly without organic solvents.

The invention relates to an anti-cancer sustained release injection containing epothilone derivative, consisting of sustained microspheres and menstruum. The sustained microspheres comprise anti-cancer drugs selected from taxane, alkylating agent and/or plant alkaloid and the like, the epothilone derivative and sustained release auxiliary material. The menstruum is a special menstruum containing suspending agent. The epothilone derivative is selected from epothilone B, epothilone D, iso-epothilone D, BMS-247550, azaepothilone B, furan epothilone D or BMS-310705. The sustained release auxiliary material is selected from poly-dl-lactide, the glycolic acid copolymer of the poly-dl-lactide, polyethyleneglycol, the polylactide copolymer of the polyethyleneglycol, carboxyl terminated polylactide copolymer, fatty acid and decanedioic acid copolymer, etc. The suspending agent is selected from carboxymethyl cellulose and the like with the viscosity of 100cp to 3000cp (under the temperature of 25 DEG C to 30 DEG C). The sustained release microsphere can also be made into a sustained release implant. The sustained release injection is injected or arranged in or around the tumour and can release drug at partial position for 40 days approximately, therefore, the sustained release injection improves the local drug concentration selectively and enhances the treatment effect of non-operative treatments, such as radiotherapy, chemotherapy and the like at the same time.

The invention relates to an anti-cancer sustained release injection containing epothilone derivative, consisting of sustained microspheres and menstruum. The sustained microspheres comprise anti-cancer drugs selected from taxane, alkylating agent and/or plant alkaloid and the like, the epothilone derivative and sustained release auxiliary material. The menstruum is a special menstruum containing suspending agent. The epothilone derivative is selected from epothilone B, epothilone D, iso-epothilone D, BMS-247550, azaepothilone B, furan epothilone D or BMS-310705. The sustained release auxiliary material is selected from poly-dl-lactide, the glycolic acid copolymer of the poly-dl-lactide, polyethyleneglycol, the polylactide copolymer of the polyethyleneglycol, carboxyl terminated polylactide copolymer, fatty acid and decanedioic acid copolymer, etc. The suspending agent is selected from carboxymethyl cellulose and the like with the viscosity of 100cp to 3000cp (under the temperature of 25 DEG C to 30 DEG C). The sustained release microsphere can also be made into a sustained release implant. The sustained release injection is injected or arranged in or around the tumour and can release drug at partial position for 40 days approximately, therefore, the sustained release injection improves the local drug concentration selectively and enhances the treatment effect of non-operative treatments, such as radiotherapy, chemotherapy and the like at the same time.

The invention discloses a method for synthesizing a polylactic acid-block-polyN-isopropyl acrylamide temperature-sensitive material, and belongs to the technical field of amphipathy block copolymers. The method comprises the following steps of: initiating ring-opening polymerization of L-lactide by using tetra(2-hydroxyethyl) phenyl porphyrin to prepare hydroxylated star-shaped polylactic acid taking porphyrin as a core terminal; carrying out esterification reaction on the hydroxylated star-shaped polylactic acid taking porphyrin as the core terminal to obtain a macromolecular chain transfer agent; and preparing a novel star-shaped polylactic acid-block-polyN-isopropyl acrylamide temperature-sensitive material from the macromolecular chain transfer agent and a temperature-sensitive N-isopropyl acrylamide monomer by using a reversible addition-fragmentation chain transfer polymerization method. According to the method, a mild polymerization condition is adopted to facilitate the preparation of the star-shaped polylactic acid-block-polyN-isopropyl acrylamide temperature-sensitive biological material with polyN-isopropyl acrylamide adjustable in length and porphyrin as a core.

The invention discloses a synthesis method and device for rapidly producing lactide at high yield. The method comprises the steps: adding a lactic acid single component or lactic acid into a catalystdouble component, enabling the mixture to enter an oligomer preparation system through a mixer, increasing the residence time through bottom circulation, synthesizing oligomeric lactic acid, and enabling a gas-phase component to pass through a rectification system, so as to improve the yield of oligomeric lactic acid; removing unreacted lactic acid and water from the oligomeric lactic acid througha purification device; and adding a catalyst into the light-component-removed oligomeric lactic acid, allowing the mixture to pass through a mixer, allowing the mixture to enter a depolymerization reactor, depolymerizing so as to obtain lactide, allowing heavy components to enter the depolymerization reactor again through reflux, and allowing light components to pass through a purification and recovery system so as to obtain the lactide product. With the adoption of the device, lactide can be efficiently synthesized, crude lactide with the yield of 94-98% can be obtained within short residence time of 0.5-5 minutes, the molecular weight of the heavy-component polylactic acid is slowly increased, and the heavy-component polylactic acid can be returned for depolymerization; after the lightcomponents pass through a simple purification system, the content of L-lactide, D-lactide or DL-lactide in the lactide product is 94%-98%, and the content of meso-lactide is 0.5%-5.5%.

The invention provides a method for synthesizing a polylactic acid which has no metallic residue and has controllable molecular weight. The method is as follows: a reaction solvent is added into lactide to prepare a lactide solution the mol concentration of which is between 0.5 and 1.5 M under the protection of inert gas, and an initiator and catalyst are added into the lactide solution in turn, and subjected to polymerization for 0.25 to 2 hours, wherein the mol ratio of the lactide to the initiator to the catalyst is 6-350 to 1 to 0.06-0.35; a terminator is added into the lactide solution, and subjected to termination reaction for 10 to 20 minutes, wherein the mol ratio of the initiator to the terminator is 1 to 1-5; and methanol is prepared, wherein the volume ratio of the reaction solution to the methanol is 1 to 10-20, the reaction solution is dripped into the methanol to form polylactic acid deposit, and the polylactic acid deposit is separated out, filtered, subjected to methanol washing for 2 to 3 times, and subjected to vacuum drying for 24 to 48 hours at a temperature of between 20 and 40 DEG C to obtain the product. The synthesis method can be performed under the condition of room temperature and normal pressure, has high product yield and simple technique, does not require the conditions of heating and decompression, is easy to operate, and can effectively control the molecular weight of the polylactic acid product; and the product has no metallic residue and can be used as a medical material.

A biodegradable shape memory polymer is prepared through synthesizing poly-L-lactide oligomer, synthesizing poly(glycolide/caprolactone) cooligomer and using diisocyanate-type coupling agent to couple them together to obtain polyblock copolymer. Its advantage is high effect to hold the thermal deformation and thermally restoring the original shape.

The invention discloses a folate-polyethylene glycol-polylactic acid segmented copolymer micelle encapsulated with a hydrophobic anticancer drug and a preparation method of the segmented copolymer micelle. The preparation method comprises the steps as follows: bis-amino polyethylene glycol polymer is prepared firstly; mono amino polyethylene glycol tert-butyl ester polymer is prepared by the bis-amino polyethylene glycol polymer; the mono amino polyethylene glycol tert-butyl ester polymer is cross-linked with lactide to obtain tert-butoxy acylamino polyethylene glycol-polylactic acid polymer, and the tert-butoxy acylamino polyethylene glycol-polylactic acid polymer reacts with trifluoroacetic acid to obtain amino-terminated polyethylene glycol-polylactic acid polymer; and the amino-terminated polyethylene glycol-polylactic acid polymer and activated folate react away from light to obtain the folate-polyethylene glycol-polylactic acid polymer. The compound has hydrophilia , biocompatibility and water solubility of the hydrophobic segment, material absorption and cell adhesion of protein can be reduced, the circulation time of the drug in blood is prolonged, and the formed copolymer has modificability; a tumor target compound with low molecular weight and hydrophilic polyethylene glycol-4000 segmer are bonded to form a hydrophilic segment; and the hydrophobic segment is polylactic acid, and the hydrophobic anticancer drug is embedded into the hydrophobic segment, so that the toxic and side effects are reduced.

The invention relates to a preparation method of a composite small-caliber artificial blood vessel, and a product thereof. The preparation method comprises the following steps of decellularizing a coronary artery to obtain a decellularized blood vessel; then heparinizing the decellularized blood vessel, using a mixed electrospinning solution of gelatin and poly L-lactide-caprolactone (PLCL) for spinning, and removing an organic solvent, thus obtaining the small-caliber artificial blood vessel. The prepared artificial blood vessel is a double-layer tissue engineering blood vessel, adopts decellularized porcine coronary artery as an artificial blood vessel inner layer, has good compliance and cytocompatibility, and can promote cell adhesion, proliferation and differentiation, and spreading so as to accomplish reendothelialization of the blood vessel; an outer layer is a blending layer of the PLCL and the gelatin, so that the mechanical property of the blood vessel is improved, cells of smooth muscle and the like are favorably intruded, and a middle layer of the blood vessel is formed; the inner surface of the inner layer can be modified by different drugs such as heparin, so that theantithrombus of the artificial blood vessel is improved, the blood vessel intima formation is promoted, and the blood vessel is favorably rebuilt.

The present invention is preparation process of biodegradable alternating magnetic field driven shape memory composite polymer material. The composite polymer material is mixture of copolymer of L-lactide and glycolide and/or epsilon-caprolactone and nanometer Fe3O4 particle coated with poly-L-lactide, polyglycolide or poly-epsilon-caprolactone in the weight ratio of 70-90 to 10-30. Compared with available technology, the present invention has the features of non-contact initiated shape memory function, high restoring ability and mechanical performance suitable for use in medical product, capacity of being used in developing in nuclear magnetic resonance, and targeting function for no-duct conveyance.

The invention discloses an in-situ fiber-forming strengthened degradable medical elastic composite material and a preparation method thereof. The composite material is prepared by premixing polyglycolic acid or poly-(L-lactic acid) and poly-(L-lactide-tao-caprolactone) by a weight ratio of 20:80 to 5:95 in an inert gas atmosphere; extruding the mixture in a plastic extruder with a screw rotation speed of 10-80 r/min; hauling the extruded mixture by a hauling machine at a hauling speed of 1-30 m/min; controlling a die diameter/a spline diameter to be 1-6; and quenching with water in a hauling process. The composite material can be fully biologically degraded, has obviously improved tensile strength, enables fused mass to have little abrasion on the inner wall of an equipment cavity in the processing process and can be used in medical fields, such as degradable catheters, elastic fascia, artificial skin, and the like.

The invention relates to a method of preparing acyclic polyesters with different degrading speeds or their products, and the characteristic: in the polymerizing course and/or in processing course of them and their products, adding in lewis acid catalyst in weight percent of 0.1-6%. The method is simple and easy to apply, the addition of the lewis acid catalyst is low and the degrading and accelerating effects of the lewis catalyst are remarkable and the lewis acid catalyst has no effect on the biocompatibility and biodegradability of the acyclic polyester, and according to practical requirements, by adding different quantities of catalyst, it can regulate and control the degrading speed of the acyclic polyester, so as to meet different use requirements, especially able to enlarging the application range of acyclic polyesters with slower degrading speeds, such as poly-epsilon-caprolactone, poly L-lactide, etc.

The invention discloses application of chemoembolization porous microspheres with a microwave sensitization function in preparing a medicine or preparation for treating tumor. The adsorbate of the microspheres is inorganic salt and a chemotherapy medicine, the skeleton of the microspheres is poly(lactide-co-glycolide), the diameter of the microspheres is 20-700mu m, and the specific surface is greater than 10m<2>/g. The invention also provides a preparation method of the chemoembolization porous microspheres. The chemoembolization porous microspheres disclosed by the invention have good microwave sensitization heating and tumor blood vessel embolization function, exhibit regular spherical shapes, and have high porosity, narrow particle size distribution and controllable particle size; in addition, the chemoembolization microspheres with microwave sensitization prepared from the poly(lactide-co-glycolide) are applied to treatment of cancer for the first time, acquire an excellent tumor inhibiting effect and have good clinical application value.

The invention belongs to the field of bone scaffold preparation, and particularly discloses a method for preparing a hydroxyapatite/L-polylactide composite bone scaffold. The method comprises the following steps: carrying out surface modification on L-polylactide powder by utilizing polydopamine; soaking the modified powder in a simulated body fluid to generate hydroxyapatite on the surface of theL-polylactide powder in situ, filtering, cleaning, drying and grinding the obtained powder to obtain a composite powder, and performing selective laser sintering on the obtained composite powder to prepare the hydroxyapatite/L-polylactide composite bone scaffold. In the composite bone scaffold prepared by the method, the hydroxyapatite is uniformly distributed in a L-polylactide matrix, and strong interface bonding exists between the hydroxyapatite and the L-polylactide.