47 results about "Dextran Derivatives" patented technology

The present invention relates to one kind of environment responding aquogel copolymer and its preparation process. The aquogel consists of: N-isopropyl acrylamide 10-90 wt% and methacrylate dextran derivative 10-90 wt%. The preparation process of the environment responding aquogel copolymer includes chemical modification of dextran with GMA to synthesize methacrylate dextran derivative, MA-Dex, with reaction activity; and subsequent copolymerization of MA-Dex and NIPA to obtain the said environment responding aquogel copolymer P(NIPA-co-MA-Dex). The aquogel copolymer has high temperature sensitivity and quick responding speed as well as high strength and excellent biocompatibility. The preparation process is simple, needs no special apparatus and is easy to realize in industry.

The invention discloses a new method for preparing an intelligent glucose-sensitive insulin controlled-release biological material. The method comprises the following steps of: firstly, dissolving glucose derivative monomers with C=C derivatives and concanavalin A derivative monomers with C=C double bonds in buffer solution to produce monomer solution; secondly, adding a catalyst in the monomer solution to perform free radical polymerization at a certain temperature; and finally, removing unreacted reactant through dialysis to obtain the glucose-sensitive insulin controlled-release biologicalmaterial. The preparation method has the advantages of convenient implementation, fast reaction process, mild reaction condition and easy production preparation on a large scale. The obtained glucan-concanavalin A insulin controlled-release biological carrier material has the advantages of good glucose-sensitive property and excellent insulin controlled-release performance.

The invention discloses a yeast beta-D-glucan derivative and a preparation method and an application thereof. The yeast beta-D-glucan derivative is obtained by substituting the hydroxyl of a yeast beta-D-glucan molecule with a sulfate group, wherein the degree of substitution of the sulfate group is 0.28-0.32 or 0.40-0.51. The invention further provides a method for preparing the yeast beta-D-dextran derivative, which comprises the following steps: dissolving yeast beta-D-glucan into an organic solvent and adding an esterifying agent for esterification reaction to obtain the yeast beta-D-dextran derivative. The contrastive analysis of a scanning electron microscopy discovers that the sulfated and modified yeast beta-D-glucan derivative is in a grid shape and has obvious grooves, the specific surface area is obviously increased, and the adsorption capacity is remarkably enhanced. An adsorption effect test shows that the adsorption quantity of zearalenone by the yeast beta-D-glucan derivative reaches 18.6528 mug/mg and is remarkably higher than that of the zearalenone by a yeast cell wall and the yeast beta-D-glucan.

A process for producing a glucan derivative modified with a cyclic ester with a highly suppressed homopolymerization of a cyclic ester is provided.

In a production process for a modified glucan derivative, by allowing a glucan derivative having a hydroxyl group to react with a cyclic ester in a solvent in the presence of a ring-opening polymerization catalyst to give a modified glucan derivative in which the cyclic ester is graft-polymerized to the glucan derivative, (1) the ring-opening polymerization catalyst is a metal complex which by itself does not initiate the polymerization of the cyclic ester; and (2) the solvent comprises a nonaromatic hydrocarbon solvent having a solubility in water of not more than 10% by weight at 20° C.

The present invention discloses a degradable polymer microcapsule injection preparation of oil-soluble medicine and its preparation method. It uses polysaccharide containing double-bond and polylactic acid which have good biological compatibity and biological degradability as capsule shell material, adopts O/W emulsion polymerization technique and controls the ratio of mixing polysaccharide and polylactic acid to obtain the invented medicine microcapsule injection preparation whose grain size is 100-3000 nm.

The invention belongs to the field of biomedical science, and particularly relates to a preparation method of injectable self-curing hypoglycemic hydrogel. The preparation method is characterized in that dextran (Dex) and polyethylene glycol (PEG) are used as main raw materials and are subjected to chemical modification so as to obtain derivatives of the dextran and the polyethylene glycol, namely the furyl dextran derivative (DF) and the maleimide polyethylene glycol (Mal-PEG-Mal) derivative, the self-curing hydrogel material controlled in gelling time can be obtained through Diels-Alder reaction, and a hypoglycemic medicament comprising one or more of sulfonylureas, biguanides, insulin and the like is loaded on the hydrogel material. The purpose of stably controlling blood sugar for a long time is achieved by slowly releasing the hypoglycemic medicament, the morbidity of diabetic complications is reduced, and even the life span of patients is prolonged.

The invention discloses a preparation method of a yeast beta-1,3-D-glucan derivative. Puffing technology and acid-base solution treatment are combined in the method to prepare the yeast beta-1,3-D-glucan derivative, so that the time for preparing the yeast beta-1,3-D-glucan can be greatly saved, and the extraction cost can be reduced.

Disclosed is a method for producing a cyclic ester-modified glucan derivative wherein generation of homopolymers of the cyclic ester can be highly suppressed. Specifically disclosed is a method for producing a modified glucan derivative to which a cyclic ester is graft-polymerized, wherein a glucan derivative having a hydroxyl group and a cyclic ester are reacted in a solvent in the presence of a ring-opening polymerization catalyst. In this method, (1) the ring-opening polymerization catalyst is composed of a metal complex which does not initiate polymerization of the cyclic ester by itself; (2) the solvent is composed of an aromatic hydrocarbon solvent having a solubility in water at 20° C. of not more than 10% by weight; and (3) the ratio of the solvent is set at not less than 60 parts by weight per 100 parts by weight of the glucan derivative having a hydroxyl group.

The invention concerns pharmaceutical compositions with wound healing or anti-complementary activity, and their uses, said compositions comprising, (1) at least a dextran derivative of general formula DMC_aB_bSu_c, a, b, and c respectively representing the degrees of substitution in the groups MC, B and Su, wherein a≧0.6, b=0 or ≧0.1, and c=0 or ranges widely between 0.1 and 0.5 for a wound healing composition, and a≧0.3, b≧0.1 and c=0 or ranges widely between 0.1 and 0.4 for a composition with anti-complementary activity; (2) and at least a pharmaceutically acceptable carrier, said dextran derivative being present in a single unit dose or at a concentration adapted to the desired wound healing or anti-complementary activity.

This invention discloses new immobilized trypsin and its producing method. Compatible immobilized enzyme carrier that synthesized by dextran derivative is used, enzyme and carrier are used to produce the fixed trypsin by crosslinking agent, the enzyme activity of immobilized trypsin is 60 to 85 percent of non immobilized, activity recovery is 60 to 85 percent. The material is easy to gain, operation is simple, the immobilized trypsin has good stability, it can be repeated used, it can be dissolved in substrate solution and react with solid substrate, its catalysis efficiency is high, and has good application value.

The invention provides a modified glucan derivative (e.g., modified cellulose acylate) which is suitable for use in optical applications such as optical films. The modified glucan derivative comprises a glucan derivative (e.g., cellulose acetate) and a hydroxy acid ingredient graft-polymerized therewith, wherein (1) the hydroxy acid ingredient comprises a lactone, (2) the hydroxy acid ingredient comprises an a-hydroxy acid ingredient (e.g., lactic acid or lactide) and the proportion of the hydroxy acid ingredient graft-polymerized is 0.1-5 mol on the average in terms of hydroxy acid amount per mol of the glucose units constituting the glucan derivative, or (3) the proportion of the hydroxy acid ingredient by which the glucan derivative is substituted, degree of polymerization of the graft chains, degree of substitution of the glucan derivative (e.g., degree of acetyl substitution), etc. are regulated, whereby the modified glucan derivative has a glass transition temperature of 70 DEG C or higher.

The invention discloses a 1,3-beta-D glucan derivative, a kit, a preparation method and a method for determining the content of 1,3-beta-D glucan. The invention provides a 1,3-beta-D glucan magnetic particle chemiluminiscence immunoassay kit which combines a magnetic particle separation technology, a biotin-avidin amplification technology and a chemiluminiscence analysis technology. Meanwhile, a biotinylated 1,3-beta-D glucan antigen derivative and an enzyme-labeled 1,3-beta-D glucan antigen derivative are prepared from the 1,3-beta-D glucan antigen derivative, so that two systems (1, the biotinylated 1,3-beta-D glucan antigen derivative plus an antibody enzyme-labeled reagent and plus a calibration solution; 2, the enzyme-labeled 1,3-beta-D glucan antigen derivative plus a biotinylated 1,3-beta-D glucan mouse monoclonal antibody and plus calibration liquid) are constructed, and the 1,3-beta-D glucan in a sample can be tested, so that different enterprises have more flexible selection when developing the kit, and the kit can be realized by only preparing the intermediate, namely, the 1,3-beta-D glucan antigen derivative.

The invention provides an amphiphilic dextran derivative carrier for targeting tumor-associated fibroblasts and preparation and application of a pharmaceutical composition of the amphiphilic dextran derivative carrier. The amphiphilic dextran derivative carrier comprises a derivative skeleton modified by hydrophilic dextran carboxyl, an FAP-alpha responsive peptide fragment connecting arm and a hydrophobic group molecule. The amphiphilic derivative is self-assembled in an aqueous solution to form nanoparticles, and molecules with pharmacological activity can be physically loaded for tumor treatment. The amphiphilic dextran derivative carrier is mainly characterized in that: (1) after the nanoparticles reach a focus part, a specific peptide fragment connecting arm can be subjected to enzyme digestion by FAP-alpha which is specifically and highly expressed on the surface of tumor-associated fibroblasts, so that the nanoparticles are rapidly degraded; and (2) the pharmacological active molecules which are physically loaded are quickly released from the disintegrated nanoparticles, tumor-associated fibroblasts can be effectively killed or the function thereof can be inhibited, the physical barrier of a tumor matrix can be weakened, and the permeation of an anti-tumor preparation can be promoted when the nano-particles are combined with other anti-tumor preparations, so that the treatment effect of the anti-tumor preparation can be effectively improved.

The invention discloses a glucan derivative and an additive containing the glucan derivative. The glucan derivative has a structure as shown in formula I which is described in the specification. According to the glucan derivative disclosed by the invention, two fatty acid ester groups are bonded to the tail end reduction end of dextran bya proper linking group, so that the amphiphilic glucan derivative disclosed by the invention is provided witha double-tail structure, and then the amphiphilic derivative with good biodegradability and good surface activity is obtained and can be widely appliedto pharmaceutical preparations.

The invention relates to the field of medical preparations, in particular to fluorescence specific nanometer iron oxide hybrid dispersion liquid for cancer metastatic lymph node tracing as well as a preparation method and a purpose of the fluorescence specific nanometer iron oxide hybrid dispersion liquid. The fluorescence specific nanometer iron oxide hybrid dispersion liquid for cancer metastatic lymph node tracing comprises a dextran derivative, iron oxide particles and water; the dextran derivative is combined with the iron oxide particles to form a nanometer iron oxide hybrid which is uniformly dispersed in the water and is prepared from the dextran derivative and ferric salt through a coprecipitation method; and the dextran derivative is prepared from 5-aminolevulinic acid and oxidized dextran through Schiff base reaction. The prepared fluorescence specific nanometer iron oxide hybrid dispersion liquid is hopeful to be applied to evaluation of gastrointestinal cancer metastatic lymph nodes and can be coupled to an anti-tumor drug through function derivatization of dextran so as to realize the purpose of diagnosis and treatment integration.

The present invention provides a composition comprising a polysaccharide to enhance transfection of a cell with a nucleic acid. The present invention also provides a method for transfecting a cell with a nucleic acid comprising the steps of forming a polyionic complex of the nucleic acid and a polysaccharide; and bringing about uptake of the polyionic complex by the cell. Preferably, the cell is selected from bone marrow mesenchymal stem cells, nervous system cell lines, adipose tissue stem cells, immunocytes, neurons, and chondrocytes. Moreover, preferably the polysaccharide is a cationized pullulan derivative, a cationized dextran derivative, or a cationized mannan derivative.