865 results about "Chitosan derivative" patented technology

The present invention provides one kind of water gel containing natural high molecular material and its preparation process. The water gel has cross-linking degree of 70-95 % and water absorption of 500-80000 %, and contains natural high molecular material or its derivative selected from chitin, chitin derivative, chitosan, chitosan derivative, carrageenin, etc. The water gel may have synthetic high molecular material, inorganic filler, cross-linking sensitizer, medicine and other assistant added. It is prepared through radiation cross-linking, with the radiation dosage being 10-40 kGy. The water gel of the present invention has high water absorption, high flexibility, good medicine slow releasing performance, and may be used in wound dressing, etc.

There is disclosed hydrogel compositions comprising a combination of at least two of three components selected from non-acidic poly (N-vinyl lactam), chitosan derivatives and water-soluble multifunctional amine-containing polymers in various ratios. The hydrogels are useful as cavity-filling wound dressings, burn dressings, drug delivery systems, cosmetic masks, conductive electrodes, prostheses and wraps.

The invention relates to a method for preparing composite biological medical material used to avoid adhering organisms, wherein said film is formed by two layers; the layer used as base material is formed by degradable composite macromolecule polylactic acid, glycolic acid, or their copolymer, treated by static spin technique, to make film fiber into nanometer level; then coats one layer of degradable natural macromolecule chitose or relative derivant on the base film, to be treated to obtain the degradable composite biological medical film; and the invention can add different amounts of medical elasticizer between two layers to adjust the degrade speed. The invention can improve immunity with haemostasis function, etc.

A medical composition is provided which is advantageous as a sealant for wound openings as well as have a function promoting healing of intractable wound or incision wound, and which accelerate tissue regeneration but does not cause any side effect such as canceration. The present invention relates to a medical composition comprising a photo-crosslinkable chitosan derivative and a wound healing promoter. The photo-crosslinkable chitosan derivative is preferably a polymer obtainable by incorporating a carbohydrate chain containing a reducing terminal to at least one portion of amino groups of chitosan back bone and incorporating a photoreactive group to at least another part of the amino groups. The wound healing promoter is preferably a growth factor.

The invention relates to a preparation method of a polyether-grafted chitosan derivative crude oil desalting demulsifier. The preparation method comprises the following specific steps: firstly, performing formylation modification on polyethylene glycol monoethylether; secondly, preparing glycidyl dimethyl alkyl ammonium chloride; thirdly, preparing quaternarization carboxyalkyl chitosan; fourthly, enabling formylation modified polyethylene glycol monoethylether to react with carboxy alkyl chitosan to obtain the polyether-grafted chitosan derivative crude oil desalting demulsifier. The polyether-grafted chitosan derivative crude oil desalting demulsifier disclosed by the invention is prepared by taking chitosannatural polymeric compounds as raw materials, and has the advantages of wide sources, naturalness, no toxicity, sustainability, good biocompatibility of a product, degradability and the like. The prepared demulsifier is good in demulsifying and dehydrating effect; meanwhile, a demulsifying molecule contains a large amount of carboxyalkyl groups and quaternary ammonium salt groups which have strong combining capacity to metal cation, ions with negative electricity such as naphthenic acid radicals as well as particles of which the surfaces are electronegative, so the polyether-grafted chitosan derivative crude oil desalting demulsifier has capacity of removing oil-soluble salts while demulsifying.

Water-based, substrate treatment compositions contain (A) at least one chitosan selected from chitosan and a chitosan derivative, and (B) a metal compound containing at least one metal selected from Ti, Zr, Hf, Mo, W, Se, Ce, Fe, Cu, Zn, V and trivalent Cr. In particular, the water-based, substrate treatment compositions can improve the interlayer adhesion between metal materials and resin coating layers such as films or coatings, and can also improve the corrosion resistance and solvent resistance of such metal materials.

A cosmetic formulation containing an alkylated chitosan derivative, a polybasic carboxylic acid or an oxidized polysaccharide, and water, for moisturizing and/or softening skin is provided. The formulation is in the physical state of a viscous liquid or a gel, and when applied to skin, serves to moisturize and soften the skin. One embodiment of the formulation comprises PEG-chitosan and hyaluronic acid at a pH of about 3.5 to about 5.5. The formulation may be applied to skin as a bulk composition, on a towel or wipe, or in the form of a facial foam mask.

Biopolymer beads and hydrogels are useful in the remodeling, repair and reconstruction of the heart, as well as in modification of electrical conduction in the heart. Various types of beads are useful, including beads comprising a core of alginate polymers which may or may not be bonded to peptides; beads comprising a core in which peptides are dispersed with alginate polymers, and a chitosan film ionically bonded to available alginate polymers at the surface of the core; beads comprising a core in which peptides and chitosan derivates are dispersed with alginate polymers and form alginate-peptide complexes to which the chitosan derivatives are bonded; and beads comprising a core of chitosan polymers which may or may not be bonded to peptides. The heart may also be treated with a hydrogel agent comprising alginate polymers and peptides covalently bonded to the alginate polymers.

The invention relates to a method for making a chitosan derivative. The method is characterized in that: firstly, the purified chitosan is activated by a strong base to form a hydroxyl-K type chitosan; secondly, a 1, 2-butyl oxide linkage is taken as an etherifying agent, an isopropanol is taken as a disperse phase, the reaction lasts 2 to 4 days moderately at room temperature; after the reaction is finished, 8 to 10 times volume of acetone is precipitated and washed to be neutral as well as is dried in vacuum at a temperature of 50 DEG C to obtain the white powder. The hydroxybutyl chitosan with different degrees of substitution is obtained by controlling the proportion of the chitosan and the 1, 2-butyl oxide linkage and the reaction time. The method has the advantages of good water-solubility and the existence of the temperature sensitivity at a physiological temperature.

The invention relates to a method for preparing an antibacterial film of a quaternarized chitosan iodine complex. The method comprises the following steps: inserting quaternary ammonium salt on the hydroxyl group or amino group of a chitosan structure unit to prepare a quaternarized chitosan derivative; soaking a blend film of the quaternarized chitosan derivative and gelatin or poval into a simple substance iodine solution for 4-6 hours to obtain the antibacterial film of the quaternarized chitosan/gelatin or poval iodine complex, or directly preparing a quaternary ammonium salt chitosan iodine complex from the quaternarized chitosan derivative and simple substance iodine, and then mixing the quaternary ammonium salt chitosan iodine complex with gelatin or poval to prepare the blend antibacterial film containing iodine. By using the method, the water solubility and the biological activity of chitosan can be improved; simple substance iodine is stabilized and complexed by utilizing the affinity of a quaternary ammonium salt group and an iodine molecule; according to the different positions of a human body, the prepared antibacterial film can be compounded with other materials; a chitosan base has hemostasis, antiphlogosis and tissue repair functions on human body wound, can reduce the stimulation of iodine on the wound and controls the release of iodine, and the double effects of the chitosan base and iodine provide an ideal curing environment for a wound surface.

The medical chitosan dressing is mixture of chitosan in 1 weight portion, Chinese medicine extract in 0.01-10 weight portions, chitosan derivative in 0.01-10 weight portions, and metal ion in 0.0001-0.05 weight portion. The Chinese medicine extract is bletilla tuber polysaccharide or natural indigo; and the chitosan derivative is one of hydroxypropyl chitin, hydroxypropyl chitosan, succinyl chitin, succinyl chitosan, carboxymethyl chitin and carboxymethyl chitosan. The medical chitosan dressing has the functions of promoting healing of the wound and stopping bleeding, inhibiting bacterial growth, and has excellent wound pasting performance.

A microcapsule having a mean diameter of from about 0.1 to about 5 mm, a membrane and a matrix containing at least one active principle wherein the microcapsule is the product of the process comprising the steps of (a) forming an aqueous matrix by heating an aqueous solution comprised of a gel former, an anionic polymer selected from the group consisting of a salt of alginic acid and an anionic chitosan derivative and active principle; (b) forming a dispersed matrix by adding the aqueous matrix in an oil phase; (c) contacting the dispersed matrix with an aqueous solution of chitosan.

A bioadsorbent for treating the sewage containing heavy metal ions (5-2000 ppm) and with 2-11 of pH value is prepared by coating method and blotting method to coat the surface of mycelia (citrobacteria, yeast, etc) with the glucosan, chitosan, or chitosan derivative. Its advantages are low cost, high adsorption capacity (30-100 mg/g) and cyclic use (20 times).

The present invention is directed to a pharmaceutical preserving composition comprising: (a) at least one chitosan or chitosan derivative and (b) at least one buffer solution, as well as methods of preserving contact lens solutions and disinfecting contact lens using such composition. The present invention is further directed to a method of preparing O-acetylated chitosan or chitosan derivatives comprising the steps of dissolving the chitosan or chitosan derivative into an aqueous acidic solution and reacting the chitosan or chitosan derivative with an acetylating agent in the presence of a phase transfer reagent.

A process for producing a chitin derivative and/or a chitosan derivative that have a crosslinked structure, which comprises irradiating a paste of a mixture consisting of 100 parts by weight of a chitin derivative and/or a chitosan derivative and 3˜1,000 parts by weight of purified water.

The invention relates to a hyaluronic acid-modified amphipathic chitosan derivative carrier with tumor microenvironment specificity drug release effect. The hyaluronic acid-modified amphipathic chitosan derivative carrier is characterized in that firstly, a hydrophilic group is introduced into a chitosan skeleton; then, a hydrophobic group is introduced into a specifically degradable link arm containing disulfide bonds, so as to realize the amphipathic function; the amphipathic derivative is assembled into nanomicelle by self in a waterborne medium, and is further modified by a charge adsorbing principle to target the molecular hyaluronic acid; the nanomicelle can effectively load an anti-tumor drug, and the hyaluronic acid is targeted to the tumor microstructure and then is degraded by hyaluronic acid enzyme in focus cells, so that the drug can be quickly released from the nanomicelle to act on the focal part, thereby obviously improving the concentration, therapy effect and biological utilization degree of free drug on the focal part. The hyaluronic acid-modified amphipathic chitosan derivative carrier has the advantages that the carrier which carries pharmaceutical activity or pharmacological activity molecules can be applied to internal injection of blood vessels or muscles or oral administration, so as to obviously improve the anti-tumor activity of drug; the preparation method is simple, the technology is matured, and the preparation method is suitable for large-scale production.

The invention provides a new chitosan derivate-chitosan biguanide muriate, its preparation and usage, in which, the repeat unit is 2-biguanide glucose muriate, the substitution degree of guanidine is 15-50%, and the molecular weight is 0.5-25 ten thousand. This invention uses the reaction of chitosan and dicyandiamide to prepare chitosan biguanide muriate, and has advantages of mild reaction conditions and fewer side effects. The product has good antibacterial activity and water solubility, and can be widely used in medicine, textile industry, agriculture and other fields.

A chitosan-metal salt chelate as the wood preservative is prepared through dispersing chitosan or its derivative in water, dispersing at least one salt of Cu, Zn, or rare-earth metal in it, heating to 36-60 deg.C for 1.5-5 hr to obtain water-insoluble chelate, and adding at least one dilute acid to become water soluble while regulate its pH value to 2-6.

The invention relates to a chitosan or its derivative as drug carrier for carrying red sage root extract and the method, wherein the novel carrying agents include chitosan or sodium alginate for the preparation of drug-carrying beads, tanshinone pharmaceutical carrying agents using the carboxymethyl derivative of chitosan and the quaternary ammonium salt of chitosan, and the aquagel as the carrying agent of red sage root active component prepared from chitosan grafted polyethylene glycol.