424 results about "Poly l lactic acid" patented technology

The invention discloses an absorbable suture line for surgical suture and a preparation method thereof, and relates to the technical field of medical materials. The absorbable suture line for surgical suture is prepared from the following raw materials in parts by weight: 50 to 65 parts of polylactic acid, 15 to 20 parts of polyglycolic acid, 3 to 5 parts of sodium carboxymethyl cellulose, 3 to 8 parts of a toughening agent, 3 to 6 parts of an antibacterial agent, 0.3 to 0.8 part of a lubricating agent, 1 to 2 parts of sodium hyaluronate and 5 to 10 parts of polyvinyl alcohol. The toughening agent is obtained by reacting hydroxyethyl acrylate with ethylenediamine to generate a four-arm compound and then reacting with 6-caprolactone and DL-lactide. The absorbable suture line for surgical suture prepared by the invention has excellent tensile property and antibacterial property, and can meet the application requirements of clinical medical treatment.

The invention belongs to the technical field of drug delivery, and particularly relates to an M-coated PLGA-10BX compound as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing 10B-enriched boron nitride (h-10BN); extracting a cell membrane of the macrophage RAW264.7; polylactic acid-glycolic acid copolymer (PLGA) nano particles loaded with h-10BN are prepared; and finally, the bionic nano platform M (at) PLGA-10BN based on the macrophage membrane is prepared. The bionic nano-platform prepared by the invention is uniform in particle size and morphology, has relatively high biological safety, and has no obvious damage to various tissues and visceral organs. The compound can be used as a general platform for boron compound delivery, can also be used as an immune activator, is suitable for intravenous injection administration, and expands the application of boron neutron capture therapy (BNCT) in treatment of glioblastoma (GBM).

The application discloses a preparation method of a dopamine-coated poly(L-lactic acid) piezoelectric biomaterial, S1, ultrasonic dispersion of dopamine hydrochloride in an organic solvent is carried out to obtain a dopamine hydrochloride dispersion liquid; S2, poly(L-lactic acid) powder is added into the dopamine hydrochloride dispersion liquid and stirring is carried out to obtain an electrostatic spinning liquid; S3, bubbles in the electrostatic spinning liquid are removed, a nanofiber membrane is obtained through an electrostatic spinning process, high-temperature annealing is carried out on the nanofiber membrane, and cooling is carried out, so that the dopamine-coated poly(L-lactic acid) piezoelectric biomaterial is prepared. The preparation method adopts an interface anchoring effect, strong intermolecular interaction at an interface between dopamine and poly(L-lactic acid) is responsible for anchoring self-polarization poly(L-lactic acid) chains and promoting crystal nucleation, so that the prepared piezoelectric biomaterial exhibits significantly enhanced piezoelectric performance and excellent service life.

The present invention discloses drug-loaded nanoparticles targeting neuraminidase, as well as a preparation method and application thereof, belonging to the technical field of pharmaceutical preparations. The present invention connects polysialic acid and polylactic acid glycolic acid via an ester bond to obtain drug-loaded nanoparticles with stable structure and performance. The drug-loaded nanoparticles have the function of targeting neuraminidase and have relatively high efficiency in entering cells. Furthermore, antibiotics are dispersed in the drug-loaded nanoparticles, and an inflammatory modulator is adsorbed on the surface of the drug-loaded nanoparticles. The drug-loaded nanoparticles can deliver the antibiotics and the inflammatory modulator to Grasseria suis in pigs, releasing the antibiotics and the inflammatory modulator in the slightly acidic environment of the infected site in the pig, thereby efficiently killing Grasseria suis and reducing inflammatory damage caused by bacterial infection and toxic damage of the antibiotics. Therefore, the present invention has good application prospects in the preparation of drugs for preventing and / or treating Grasseria suis infection.

The present invention relates to an advanced dressing characterized by a powder of polymeric material based on poly(lactic-co-glycolic) acid, functionalized with dextran, maltodextrin, collagen, citric acid, chitosan, polyphenols, colloidal silver, hyaluronic acid and / or salts thereof, polyethylene glycol and alginate. The present invention further relates to a process for producing the powder and the use of the powder in treating non-necrotic skin wounds.

The invention discloses injectable poly-L-lactic acid microsphere composite gel capable of inducing rapid regeneration and instant filling of collagen, which is characterized in that poly-L-lactic acid is used as a raw material, and poly-L-lactic acid microspheres are prepared by adopting an emulsification method; the preparation method comprises the following steps: taking collagen and oxidized polysaccharide as raw materials, carrying out Schiff alkali cross-linking reaction on the collagen and the oxidized polysaccharide to prepare composite gel, and uniformly distributing L-polylactic acid microspheres in the composite gel. The aldehyde group on the oxidized polysaccharide and the amino group on the collagen are subjected to a Schiff base cross-linking reaction to form the injectable gel with a three-dimensional network structure. The cross-linked gel provides mechanical tension to uniformly disperse the PLLA microspheres, so that the microspheres are prevented from settling or agglomerating. The composite gel can also improve the hydrophilicity of the microspheres, so that the redissolution dispersity of the microsphere filler is better, and the microspheres settle more slowly. After being injected subcutaneously, the collagen gel can be instantly filled and induce rapid regeneration of collagen, has no chemical cross-linking agent residue, and reduces the risk of inflammation (such as granuloma) caused by the organism and the like.

The invention discloses a modified polylactic acid fiber and a preparation method thereof. The preparation method comprises the following steps: providing polybasic hydroxyl-terminated D-polylactic acid; the method comprises the following steps: respectively providing betaine-grafted D-polylactic acid and a poly (butylene adipate terephthalate)-epoxy-polyether co-modified organic silicon-D-polylactic acid copolymer by taking the multi-hydroxyl-terminated D-polylactic acid as a main raw material, wherein the poly (butylene adipate terephthalate)-epoxy-polyether co-modified organic silicon-D-polylactic acid copolymer; and carrying out Haake blending and melt spinning on the betaine-grafted D-polylactic acid, a poly (butylene adipate-co-modified organosilicon-D-polylactic acid) copolymer, L-polylactic acid, an antioxidant and an anti-hydrolysis agent, so as to obtain the modified polylactic acid fiber. The preparation method comprises the following steps: carrying out Haake blending and melt spinning on the betaine-grafted D-polylactic acid, poly (butylene adipate-co-modified organosilicon-D-polylactic acid copolymer, L-polylactic acid, the antioxidant and the anti-hydrolysis agent. The modified polylactic acid fiber prepared by the method has the characteristics of easy decontamination, hydrophilicity, high temperature resistance and high toughness, and can effectively avoid water washing shedding, and the comprehensive performance is obviously improved.

The invention discloses a cellulose microcrystal reinforced degradable flame-retardant PLA composite material and a preparation method thereof, and belongs to the field of bio-based functional polymer materials. The composite material is prepared from the following components in parts by weight: 80 to 100 parts of polylactic acid (PLA), 3 to 10 parts of bamboo cellulose microcrystal, 3 to 10 parts of biomass polyphosphate, 1 to 5 parts of GO-g-PLA, 10 to 30 parts of PBAT toughening agent and 0.2 to 1 part of auxiliary agent. The preparation method comprises the following steps: (1) preparing high-crystallinity bamboo cellulose microcrystals by adopting a supercritical CO2 method; (2) preparing a GO-g-PLA interface compatilizer through graft polymerization; (3) synthesizing a biomass polyphosphate flame retardant by taking pentaerythritol and diphenolic acid as raw materials; and (4) melting, blending and extruding the components. Through the synergistic effect of a flame retardant-GO-BCMC three-dimensional network, the material has excellent mechanical properties (the tensile strength is 45-47 MPa, and the impact strength is 10-12 kJ / m), high flame retardance (LOI is 28-29%, UL-94 V-0 level) and environmental friendliness (the 180-day biodegradation rate gt); the composite material can be widely applied to the fields of electronic and electric appliances, automotive trim, medical materials and the like.

The invention relates to the technical field of surface treatment, in particular to a bio-based degradable cable material and a preparation method thereof. The bio-based degradable cable material is prepared from 55 to 65 parts of matrix resin mixed by poly L-lactic acid and poly-3-hydroxybutyrate-3-hydroxyhexanoate, 4 to 6 parts of dianhydride modified castor oil polyol, 10 to 15 parts of polypentamethylene diamine adipate, 5 to 8 parts of nano reinforcing filler, 6 to 10 parts of bio-based plasticizer, 0.5 to 1.0 part of antioxidant and 8 to 12 parts of environment-friendly flame retardant. A dynamic ester bond cross-linked network formed by the reaction of a dynamic ester bond cross-linking agent dianhydride modified castor oil polyol only undergoes ester bond breakage at a high temperature exceeding a normal working range to release stress, and the temperature returns to normal and can be recombined; the semi-interpenetrating network reinforced phase poly (pentamethylene diamine adipate) and the matrix resin form an interpenetrating structure in a molecular chain interpenetrating manner, a stable heat-resistant skeleton is constructed, high-temperature deformation is effectively inhibited, the overall degradability of the material is ensured by the bio-based structure, and the balance of heat resistance and degradability is realized.

The invention provides an apigenin nanoparticle preparation as well as a preparation method and application thereof. The preparation method comprises the following steps: weighing apigenin, dissolving the apigenin in an acetone solution containing a polylactic acid-glycolic acid copolymer, or dissolving the apigenin in an acetone solution containing the polylactic acid-glycolic acid copolymer and Eudragit S100, and uniformly stirring and mixing at room temperature to obtain a mixed solution; dropwise adding the mixed solution into a polyvinyl alcohol solution, carrying out ultrasonic treatment, and removing the solvent to prepare PANPs or PEANPs. The preparation method is simple, and the prepared PANPs and PEANPs are small in particle size and high in encapsulation efficiency, can effectively penetrate through intestinal epithelial barriers and promote internalization of apigenin into cells, have a good slow release characteristic, can remarkably improve the bioavailability of apigenin, and have a good treatment effect on inflammatory bowel diseases. PANPs has a better treatment effect on ulcerative colitis, and PEANPs has a better treatment effect on diffuse colitis.

The invention relates to an absorbable bone hemostasis and repair stent. The absorbable bone hemostasis and repair stent comprises the following raw materials in parts by weight: 15-60 parts of an excipient, 15-60 parts of a softening agent and 5-70 parts of a bone repair promoting component, the excipient is prepared from a polyoxyethylene-polyoxypropylene copolymer; the softening agent comprises a semi-solid mobile phase polymer; the bone repair promoting component comprises a coating and a core, the coating comprises a polylactic acid-glycolic acid copolymer, zinc stearate and potassium bromide, the core comprises calcium phosphate particles, and the coating wraps the surface of the core. The preparation method comprises the following steps: preparing the bone repair promoting component; and preparing the absorbable bone hemostasis repair stent. The absorbable bone hemostasis and repair stent is high in hemostasis and collapse resistance and has good inflammation regulation and bone repair promoting effects. The absorbable bone hemostasis and repair stent can be used for bone hemostasis and bone repair promotion of any bone injury wound.

The present disclosure provides a hydrogel composition for tissue engineering and regenerative medicine, including naturally derived polymers functionalized with furan groups and nanoparticles of poly(lactic-co-glycolic acid)-poly(ethylene glycol) copolymer functionalized with maleimide groups. Covalent crosslinking via a bioorthogonal Diels-Alder click reaction forms a tunable, biocompatible, and biodegradable three-dimensional network. The hydrogel composition mimics the extracellular matrix and offers adjustable mechanical properties, controlled biodegradation, and therapeutic agent delivery for applications such as cartilage regeneration and drug delivery.

The invention belongs to the technical field of biological medicine, and particularly relates to a CD44 / GSH dual-response eutectic drug delivery system and a preparation method thereof.The CD44 / GSH dual-response eutectic drug delivery system comprises a microneedle array composed of a biodegradable polymer matrix formed by hyaluronic acid (HA) and poly (lactic-co-glycolic acid) (PLGA), and the microneedle array comprises a plurality of microneedles; a microneedle comprising a pharmaceutical formulation of a resveratrol-berberine co-crystal integrated into the polymer matrix; wherein the polymer matrix comprises a disulfide bond that is a glutathione (GSH) responsive switch; wherein the hyaluronic acid is capable of specifically targeting a CD44 receptor; wherein the disulfide bond can be cleaved under the condition that the concentration of glutathione in a target tissue is increased, thereby releasing the resveratrol-berberine eutectic pharmaceutical formulation; and wherein the microneedle array is configured to percutaneously deliver the resveratrol-berberine co-crystal pharmaceutical formulation to the target tissue.

The invention relates to the technical field of drug delivery, and discloses a multilayer drug-loaded microsphere for intraocular sustained-release therapy and a preparation process thereof.The multilayer drug-loaded microsphere comprises a core layer, a middle layer and a shell layer, the core layer is composed of a polylactic acid-glycolic acid copolymer (PLGA) and a first hydrophobic drug, the middle layer is formed by wrapping the core layer with carboxymethyl chitosan, and the shell layer is composed of a first hydrophobic drug and a second hydrophobic drug. The first hydrophobic drug comprises a first therapeutic drug, the middle layer comprises a second therapeutic drug, the shell layer is composed of a polylactic acid-caprolactone copolymer PLCL and a third hydrophilic drug, and the first hydrophobic drug, the second therapeutic drug and the third hydrophilic drug are different from one another. Through the layered design of the core layer, the middle layer and the shell layer and in combination with differential degradation rates of PLGA, carboxymethyl chitosan and PLCL materials, gradient release of hydrophobic and hydrophilic drugs is achieved, a drug release curve is matched with the pathological stage of intraocular diseases, macular degeneration rapidly inhibits vascular leakage in the early stage and continuously resists inflammation in the later stage, and the effect of treating macular degeneration is achieved. And the layered slow-release synergistic treatment effect is verified.

The invention provides a polylactic acid-polycitrate composite microsphere as well as a preparation method and application thereof. The polylactic acid-polycitrate composite microsphere is prepared from the following raw materials: a polycitrate prepolymer and poly-L-lactic acid. According to the polylactic acid-polycitrate composite microsphere provided by the invention, the polycitrate prepolymer is introduced, so that mechanical-degradation double-phase matching of a material can be realized, the hydrophobicity of the poly-L-lactic acid can be reduced, the hydrophilic-hydrophobic balance of the surface of the composite microsphere is realized, the affinity and biological activity of cells are improved, and the biocompatibility of the composite microsphere is improved. And the poly citrate prepolymer and the poly-L-lactic acid are matched for use, so that the whole polylactic acid-poly citrate composite microsphere has bionic viscoelasticity, thereby promoting the spreading of fibroblasts and the secretion of more integrin and collagen monomers, facilitating the behavior regulation and control of cells, and mildly stimulating the regeneration of collagen.

The invention discloses an absorbable suture line containing fibroin and a preparation method of the absorbable suture line, and relates to the technical field of absorbable suture lines. The absorbable suture line containing the silk protein is prepared from the following raw materials in parts by weight: 35 to 50 parts of silk protein, 10 to 20 parts of polylactic acid, 15 to 25 parts of polyglycolide-lactide, 1 to 3 parts of antibacterial agent, 2 to 5 parts of modified toughening agent, 1 to 4 parts of nano mineral filler, 0.5 to 2 parts of cross-linking agent and 2 to 5 parts of plasticizer, the preparation method comprises the following steps: reacting protocatechuic acid with ethanolamine to generate an intermediate 1; and reacting the intermediate 1 with 5, 10, 15, 20-tetra (4-carboxyl phenyl) porphyrin to generate the antibacterial agent. The prepared absorbable suture line containing the silk protein has good mechanical performance, self-repairing performance and antibacterial performance.

The invention discloses a citrus growth promoting fertilizer and a fertilization method thereof, and relates to the technical field of chemical fertilizer production, the citrus growth promoting fertilizer comprises 40-60 parts of macroelements, 15-25 parts of medium elements, 8-12 parts of trace elements, 10-18 parts of an organic active agent, and 5-10 parts of a slow release agent. Therefore, firstly, the nano calcium carbonate is used for replacing a traditional calcium source, and a polylactic acid-fucoidan slow-release membrane technology is combined, so that the dissolved state keeping time of calcium ions in the soil is prolonged by 30-50%, the calcium absorption rate is increased to 35% or above from the average industrial 20-30%, and the fruit cracking rate of citrus is effectively reduced; the bacillus subtilis and the seaweed extract in the organic active agent have a synergistic effect, through biological antagonism and induced resistance, the canker incidence rate is reduced to 1 / 4 of that of a control group, meanwhile, the soil microenvironment is improved through humic acid, and the root system health degree is improved by 40%.

The invention relates to the technical field of pharmaceutical preparations, and discloses a high-drug-loading risperidone sustained release microsphere for subcutaneous injection and a preparation method thereof, and the preparation method comprises the following steps: mixing risperidone, polylactic acid and dichloromethane to obtain an oil phase; dissolving a pore-forming agent in water to obtain a pore-forming agent solution; mixing polyvinyl alcohol, sodium chloride and water to obtain a water phase; mixing the oil phase with the pore-forming agent solution to obtain primary emulsion; mixing and stirring the primary emulsion and a water phase until dichloromethane is completely volatilized to obtain microspheres loaded with speridone; mixing cellulose acetate, polyethylene glycol and an organic solvent to obtain a coating solution; and coating the risperidone-loaded microspheres with a coating solution to obtain the high-drug-loading risperidone sustained-release microspheres capable of being used for subcutaneous injection. According to the invention, the efficient drug loading is realized, the injection comfort is improved, the slow permeation and release of the drug are realized, and the onset speed and the long-acting treatment demand are balanced.

The present application relates to the technical field of surface treatment, in particular to a kind of biobased degradable cable material and preparation method thereof.Biobased degradable cable material includes 55-65 parts of poly-L-lactic acid and poly-3-hydroxybutyric acid-3-hydroxyhexanoate mixed matrix resin, 4-6 parts of dianhydride modified castor oil polyol, 10-15 parts of polyaminoval, 5-8 parts of nano enhanced filler, 6-10 parts of biobased plasticizer, 0.5-1.0 parts of antioxidant, 8-12 parts of environmentally friendly flame retardant.Dynamic ester bond crosslinking agent dianhydride modified castor oil polyol reaction forms dynamic ester bond crosslinking network, ester bond breakage occurs at high temperature beyond normal working range to release stress, temperature returns to normal and can recombine again;Semi-interpenetrating network enhanced phase polyaminoval forms interpenetrating structure with matrix resin in molecular chain interlacing mode, constructs stable heat-resistant skeleton, effectively inhibits high-temperature deformation, and its biobased structure ensures the overall degradability of the material, realizes the balance of heat resistance and degradability.

The invention discloses a polyhydroxyalkanoate composition and a preparation method thereof. The polyhydroxyalkanoate composition comprises the following components in parts by mass: 100 parts of polyhydroxyalkanoate; 0.5 to 5 parts of unsaturated D-polylactic acid; 0.5 to 5 parts of poly (L-lactic acid); the preparation method comprises the following steps: S1, carrying out melt blending on the polyhydroxyalkanoate and the unsaturated D-polylactic acid, and enabling the polyhydroxyalkanoate and the unsaturated D-polylactic acid to fully react, so as to obtain an intermediate product; and S2, carrying out melt blending on the intermediate product obtained in the step S1, poly-L-lactic acid and an ester exchange inhibitor to finally obtain the polyhydroxyalkanoate composition with excellent thermal stability, high melt strength and high crystallization speed.

The application discloses a functional probiotic microencapsulated intestinal shield system and a preparation method and application thereof. A core layer comprises four probiotics, i.e., lactobacillus acidophilus La-14, animal bifidobacterium Bb-12, lactobacillus rhamnosus GG and lactobacillus reuteri DSM 17938, and the weight ratio is 3:4:2:1, and the total viable bacterial count is greater than or equal to 10^10 CFU / g. An inner layer is a targeted release control layer, which is composed of ethyl cellulose, polylactic acid, chitosan and lactose, can swell in a pH 5.5 to 6.5 environment and can dissolve in a pH 6.8 to 7.2 environment. A middle layer is a buffer protection layer, which is composed of calcium carbonate, disodium hydrogen phosphate and sodium alginate, and can maintain the internal pH of the microcapsule at 4.5 to 5.5 in a gastric acid environment. An outer layer is an intelligent response protection layer, which is composed of konjac glucomannan, xanthan gum and gum arabic, and can form a protective film in a gastric acid environment with a pH less than 3.0 within 5 minutes. Through the synergistic protection of the four-layer microcapsule structure, the probiotics can achieve a high survival rate in the gastric acid environment of cats, and can be accurately released at specific positions in the intestinal tract, which is helpful to improve the intestinal health of cats.

The invention relates to the technical field of biomedical materials and wound repair, and discloses a preparation method and application of 4 '-hydroxychalcone-loaded nanofiber hydrogel, the preparation method comprises the following steps: mixing 4'-hydroxychalcone and polylactic acid according to a mass ratio of 1: (6-12), and carrying out ultrasonic treatment to obtain 4 '-hydroxychalcone-loaded nanofiber hydrogel; preparing nanofibers containing 4 '-hydroxychalcone by adopting an electrostatic spinning technology; according to the present invention, the 4 '-hydroxychalcone-loaded nanofiber hydrogel has the following characteristics that the drug in the 4'-hydroxychalcone-loaded nanofiber hydrogel can be continuously released, and the cumulative release rate can achieve 70-85% within 72 h so as to maintain the stable drug action concentration on the wound surface; meanwhile, the nanofiber hydrogel has good water retention capacity, the water retention rate of the nanofiber hydrogel can reach 90-95%, a stable wet healing environment can be provided for the wound surface, and the wound surface repairing process is facilitated.

The present invention relates to the field of lactic acid technology, and specifically discloses a kind of ultra-high purity crystalline lactic acid and its preparation method and application. The present invention carries out ultra-high vacuum evaporation crystallization on polymerization-grade liquid L-lactic acid at 6 ℃ ~ 10 ℃, 0.7kPa ~ 0.9kPa, adds L-lactic acid seed crystals when the lactic acid specific gravity is 1.34 ~ 1.35, and terminates crystallization until the lactic acid specific gravity is 1.38 ~ 1.39, thereby obtaining ultra-high purity crystalline lactic acid. The present invention utilizes the limited water solubility of lactic acid at low temperatures, and only utilizes ultra-high vacuum evaporation crystallization in one step under ultra-low temperature and ultra-high vacuum to obtain ultra-high purity crystalline lactic acid, which has a purity of more than 99.95%, a granular shape, a high crystallization rate, uniform and dense, high looseness, strong anti-caking performance, and excellent quality. The ultra-high purity crystalline lactic acid can be directly polymerized for the production of polylactic acid, which improves production efficiency, greatly reduces production costs, has excellent market competitiveness, and is suitable for large-scale production.

The invention is suitable for the technical field of food packaging materials, and provides a biodegradable lactic acid-based food packaging composite material and a preparation method thereof.The composite material is prepared from polylactic acid, polycaprolactone, tartaric acid-cysteine carbon dots, a bio-based plasticizer, an organic small molecule modifier and modified aerogel; tartaric acid-cysteine carbon dots and polycaprolactone are added to synergistically enhance the mechanical property, barrier property, antibacterial property and antioxidant property of the polylactic acid material; by adding the bio-based plasticizer, the processability and flexibility of the PLA are further improved; by adding the small organic molecule modifier, the dispersity of the carbon dots in a PLA matrix is improved, and the mechanical property, the oxidation resistance and the antibacterial property of the material are further enhanced; by adding the modified aerogel, excellent barrier property and adsorption capacity are provided, the mechanical property of the material is enhanced, and plant-derived antibacterial factors are uniformly distributed in aerogel pores, so that the growth of microorganisms is effectively inhibited.

The invention relates to the technical field of films, in particular to an optical composite film of a composite polylactic acid core layer and a preparation method of the optical composite film. The optical composite film is of a three-layer structure and comprises a composite polylactic acid core layer made of specific raw materials and amorphous polylactic acid skin layers on the two sides. The core layer is prepared from the following raw materials: poly (L-lactic acid) resin, poly (D-lactic acid) macromolecules, carboxyl-terminated poly (D-lactic acid) oligomers, a multifunctional epoxy chain amplification agent and aminated nano silicon dioxide. During preparation, key processes such as step-by-step addition of the chain extender, the D-lactic acid component and the aminated nano silicon dioxide and three-layer co-extrusion stretching are carried out, so that the molecular structure and the dispersion state of the material are synergistically optimized. The method effectively solves the technical contradiction that a traditional polylactic acid optical film is difficult to consider high light transmittance, low birefringence and low thermal shrinkage at the same time.

The application discloses a water-soluble quantum dot nanometer material and a preparation method and application thereof, and the nanometer material comprises quantum dots and carboxyl-terminated poly(lactic-co-glycolic acid) coated on surfaces of the quantum dots. The carboxyl-terminated poly(lactic-co-glycolic acid) is used for encapsulating CsPbBr3 perovskite quantum dots, and a water-soluble perovskite nanocrystal material is prepared, which can retain high quantum yield (PLQY=88%) and water-oxygen resistance (>=30 days) and almost completely retains optical performance of the perovskite quantum dots.

The application relates to the technical field of medical suture materials, and particularly discloses a non-absorbable suture with tissue self-adaptive performance, which comprises a core layer, a transition layer and an outer layer; the core layer and the transition layer are fixed through hot melt adhesion, and the outer layer is coated on the surface of the transition layer through electrostatic spinning; the core layer is a polyether ether ketone fiber with a diameter of 50-100 mu m and a tensile modulus of greater than or equal to 3 Gpa; the transition layer is a nickel-titanium alloy wire braided net with a thickness of 40-60 mu m, and the wire diameter of the nickel-titanium alloy wire is 20-30 mu m; and the outer layer is a poly-lactic acid-glycolic acid copolymer coating layer containing nano-hydroxyapatite with a thickness of 30-50 mu m; and the application further provides a preparation method of the non-absorbable suture. The non-absorbable suture has the advantages of tissue self-adaptive performance, persistent mechanical support and bioactivity, can effectively avoid tissue cutting, abrasion and suture loosening, and can reduce the incidence of postoperative complications such as inflammation and pain.

The present disclosure concerns a polymer selected from poly-L-lactic acid, poly-D, L-lactic acid and any copolymer comprising repeating units comprising L-lactic acid, or any combination thereof, for use in preventing and / or treating any damage, disease, illness, and / or condition characterized by hair loss. Compositions comprising said polymer are also disclosed for said use.

The invention provides a cardiac targeting nano drug delivery carrier based on recombinant apolipoprotein, a system, a preparation method and application. The cardiac targeting nano drug delivery carrier comprises a nano carrier core and a functional layer covalently coupled to the surface of the nano carrier core, the nano carrier core comprises an amphiphilic copolymer formed by polylactic acid-glycolic acid and polyethylene glycol; the functional layer comprises recombinant apolipoprotein A-I and heart targeting peptide; the recombinant apolipoprotein A-I contains mutation sites E191A and F225W, and the recombinant apolipoprotein A-I contains mutation sites F225W; the amino acid sequence of the recombinant apolipoprotein A-I is as shown in SEQ ID NO: 1. The cardiac targeting nano drug delivery system based on the recombinant apolipoprotein has the functions of long circulation, cardiac targeting and coordinated regulation and control of metabolism and inflammation, and can be used for precise treatment of chronic heart failure.

The invention discloses a hydrogel composition for three-dimensional culture of tumor cells and a preparation method of the hydrogel composition. The hydrogel composition is prepared from poly (lactic acid-glycolic acid) copolymer-polyethylene glycol-poly (lactic acid-glycolic acid) copolymer PLGA-PEG-PLGA and methylacryloyl gelatin GelMA, the mass ratio of the poly (lactic acid-glycolic acid) copolymer-polyethylene glycol-poly (lactic acid-glycolic acid) copolymer PLGA-PEG-PLGA to the methylacryloyl gelatin GelMA is (2-5): 10. According to the hydrogel composition, methacrylated gelatin GelMA is used as a main substrate, so that good biocompatibility and cell adhesion are provided; according to the invention, polylactic acid-glycolic acid copolymer-polyethylene glycol-polylactic acid-glycolic acid copolymer PLGA-PEG-PLGA is used as an auxiliary component, lactic acid is generated through biodegradation of the polylactic acid-glycolic acid copolymer-polyethylene glycol-polylactic acid-glycolic acid copolymer-PEG-PLGA, the pH of a microenvironment is dynamically reduced to 6.5-6.9, tumor acidic conditions are simulated, and pores formed after degradation can provide more growth and invasion spaces for tumor cells.