306 results about "Chitosan microspheres" patented technology

The invention relates to the technical field of biomedical materials, and particularly relates to a BMP microsphere loaded 3D printing porous metal stent and a preparation method thereof. According to the invention, a loaded microsphere-containing three-dimensional micro-stent is built in each hole of a 3D printing titanium stent. The problem that in the prior art, because the diameter of a hole is overlarge, cells only can be subjected to climbed growth on the two-dimensional space of the wall of the hole, and difficult to be subjected to three-dimensional hierarchical growth in the whole hole is solved, and by filling the three-dimensional micro-stent with a rhBMP-2 or rhBMP-7 loaded chitosan microsphere, a better growth and differentiation environment is provided for cells, thereby further promoting the combination of bone tissues and the stent. The three-dimensional micro-stent provided by the invention makes the complete healing of numerous patients with bone tissue defect caused by illnesses and accidents and the like possible; the three-dimensional micro-stent can also be used as a novel interbody fusion instrument, and applicable to an interbody fusion surgery, therefore, the three-dimensional micro-stent has an important clinical application value.

The invention discloses a method for preparing magnetic chitosan microspheres, relates to chitosan microspheres and provides superparamagnetic chitosan microspheres and a preparation method thereof. The magnetic chitosan microspheres comprise the following components in percentage by mass: 30 to 99 percent of chitosan and 1 to 70 percent of Fe3O4. The preparation method comprises: adding chitosan, a compound containing F3<3+> and a compound Fe<2+> into acidic solution to obtain solution A; and adding the solution A into alkaline aqueous solution to obtain solution B, and removing solidified and separated precipitates in solution B to obtain the magnetic chitosan microspheres. Compared with the conventional preparation method of magnetic chitosan microspheres, the preparation method of themagnetic chitosan microspheres is simple, easy to implement and low in cost and makes process simple. The size of the obtained magnetic chitosan microspheres is controllable, the Fe3O4 content is controllable and the magnetism is controllable.

The invention discloses a chitosan/layered silicate nano composite porous crosslinked microsphere adsorbent and a preparation method thereof; in the adsorbent, the layered silicate which is in nano-state is dispersed in the chitosan microsphere which is treated with chemical crosslinking. The preparation method is as follows: the chitosan with low molecular weight/ layered silicate intercalation solution is prepared, the intercalation solution is blended with the chitosan with high molecular weight and is contacted with alkaline coagulant to prepare the microsphere, the microsphere is treated with pre-crosslinking and crosslinking, acid solution is used for removing pre-crosslinking agent to obtain the chitosan/layered silicate nano composite porous crosslinked microsphere adsorbent. By comprehensively utilizing the characters of chitosan and layered silicate in terms of adsorption property and jointly applying intercalation composition, solidification and granulation by alkali solution, and pre-crosslinking and crosslinking techniques, a porous microsphere adsorbent which has low price and excellent adsorption performance for heavy metal ions and organic pollutants can be prepared.

The invention relates to a process for preparing an adsorbent, namely composite chitosan microsphere crosslinking resin of adsorbent, which belongs to the preparing field of adsorption resin in the water treatment adsorption technology. The invention is characterized in that hole solid adsorbent and chitosan are utilized to be the main raw material, and cross linker is utilized to be auxiliary raw material, the invention is prepared by the process of utilizing hole preparing agent to make holes, primary or secondary cross bonding, hydrolysis or non-hydrolysis, deacidizing or no deacidizing under the basis of utilizing solid adsorbent to load chitosan solution. The innvention has the advantages that the products of composite chitosan microsphere crosslinking resin of adsorbent are not only applicable to the field of water treatment, but also can be applied in the filed of textile, printing, food, medicine, cosmetic, fruit fresh-keeping and the like. And the invention also has the advantages of excellent mechanical property, stable water resistance property, high adsorption capacity, fast adsorption rate and high selectivity.

The invention relates to a preparation method of an aceptic packaging material with a release-controlling function, particularly comprising three steps: firstly, a chemical surface modifying method is adopted to cause the surface of polymer packaging materials to form certain amount of dissociable functional groups such as carboxyl, sulfonic group, amidine, etc; meanwhile, antibacterial agent nisin is coated inside chitosan hydrogel microspheres which employ carboxyl polyethylene glycol as crosslinking agent, employ water-soluble carbodiimide hydrochloride as coupling agent and have particle size smaller than 100nm; in mixed solvent with 100/0-50/50 of water/ethanol, the drug-coating chitosan microspheres through ultrasonic stirring processing is 'fixed' on the surface of modified polymer thin films through electrostatic absorption between cathodic anodic ion. Since the surface modifying methods and chitosan hydrogel formulas are different, the releasable nisin amount can reach 0.5-40 Mu g / cm<2>.

An ion-exchanging chitosan microsphere, especially a chitosan microsphere cross-linked with sulfuric acid, the preparation method and a medicinal carrier of the chitosan microsphere cross-linked withsulfuric acid. The method relates to preparing chitosan microspheres by phase separation, comprises: first adding the chitosan solution into a nontoxic oil phase, then adding an emulsifying agent anda dispersing agent, adding sulfuric acid solution for cross-linking, after reaction, washing the resultant product, drying by vacuum and getting chitosan microsphere cross-linked with sulfuric acid. The microspheres of the invention are smooth, have the sphere configuration, could be used for a medicinal controllable carrier.

The invention discloses injectable compound bone cement and a preparation method thereof. The invention further discloses a kit for preparing the injectable compound bone cement. The kit comprises solid powder and a curing liquid, wherein the solid powder comprises calcium phosphate bone cement powder and chitosan microspheres; and the curing liquid contains glycerophosphate. The injectable compound bone cement is prepared by uniformly mixing the solid power with the curing liquid, has superior scattering resistance, superior injection performance, rapid self-curing performance, high compressive strength and high biocompatibility, and can be used for preparing a biomedical material applied to bone defect reconstruction, bone fracture treatment and bone repair.

The invention discloses a medicinal sustained-release and hemostatic composition and a preparation method thereof, which belong to the technical field of novel hemostatic materials. The medicinal sustained-release and hemostatic composition comprises the composition of a medicament-loaded chitosan microsphere, chitosan and hyaluronic acid, wherein the medicament-loaded chitosan microsphere comprises medicinal grade chitosan and medicinal grade tranexamic acid. The novel hemostatic composition is prepared by using chitosan and the hyaluronic acid as a main hemostatic matrix, combining chitosan medicament sustained-release microsphere composite medicament, namely tranexamic acid, utilizing the special property of the chitosan with a hemostatic function and a medicament sustained-release function, and adopting the composition of the hyaluronic acid with good hemostatic function and high biocompatibility and the chitosan as the main matrix. The novel hemostatic composition has the advantages of stopping bleeding rapidly and releasing medicament/factors continuously and stably in a certain time, along with great economic and social benefits.

A preparation technique of chitosan microspheres immobilization lipase comprises the steps that: (1) lipase from candida SP is dissolved in phosphate buffer solution by taking chitosan microspheres as an immobilization carrier and adopting glutaraldehyde cross-linking, lipase A is obtained. (2) candida SP lipase solution of 0.70-0.80mg/mL prepared by phosphate buffer solution b with a pH value of 6.5-7.5 is added with immobilization lipase A (final concentration is 0.005-0.0055g/ml) and after being stirred, ethyl (3-dimethylamino propyl) carbodiimide hydrochloride solution is added, the mixture is then stirred to be fully immobilized, chitosan microspheres immobilization lipase B is obtained after the treatment of the mixture. The chitosan microspheres immobilization lipase prepared by the preparation technology of the invention improves apoenzyme combination rate and activity recovery, has powerful immobilization lipase activity and specific activity and the immobilization lipase can be recycled for six times.

The invention discloses an NGF (nerve growth factor) chitosan microsphere and high-bionic stent slow releasing system, which is a cylindrical collagen and chitosan nerve stent. Chitosan microspheres buried with nerve growth factors are uniformly loaded in the stent. A preparation method of the stent includes firstly, preparing the chitosan microspheres buried with the nerve growth factors by an emulsification chemical-crosslink method; secondly, preparing the collagen and chitosan nerve stent with mutually parallel axial microtubules sample structures; and finally, compounding the chitosan microspheres onto the collagen and chitosan nerve stent via after-compounding technology and preparing the NGF chitosan microsphere and high-bionic stent slow releasing system. The stent structure is similar to a normal nerve basilar membrane structure, and the stent realizes an effect of physically guiding regeneration nerves to the greatest extent. Besides, the stent can slowly release the nerve growth factors with bioactivity for 12 weeks, can lead the nerve growth factors to be effectively released to a nerve injury portion for a long time, and accordingly achieves the purpose of promoting long nerve defect repair better and faster.

The invention discloses an immobilized protease and an application method of the immobilized protease in preparation of milk casein peptides. The main preparation method of the immobilized protease is as follows: firstly, immobilized carrier chitosan microspheres are prepared; secondly, the chitosan microspheres are added into protease solution; after oscillation and absorption, glutaraldehyde solution is dripped into the solution; after cross linking, the immobilized protease is obtained. The method for preparation of the milk casein peptides adopts the immobilized protease to hydrolyze the milk caseins. The immobilized protease can be reused for a plurality of times, thereby the use efficiency is high and the production cost is effectively reduced; moreover, the immobilized protease has the advantages of convenient product separation, low cost, mild production conditions and easy control of the hydrolysis degree. The milk casein peptide product prepared has the advantages of high peptide content, superior peptide molecule weight distribution range, good quality, no bitterness, high safety and so on. The content (according to the dry basis) of the milk casein peptides prepared by the method is as high as 75.05 percent by detection; the peptide molecule weight distribution range is that: the molecular weight which is lower than 2409 daltons reaches 97.79 percent.

This disclosure relates to microspheres emboli and method of making them. The recoverability of lyophilized microspheres is optimized by adding trehalose prior to lyophilization of the microspheres and vortexing the lyophilized microspheres. The optimization can be useful in maintaining physical properties, shapes, and the drug release level of the microspheres for emboli. Chitosan microspheres can be useful in stably causing emboli in blood vessels, and precisely adjusting the release of a drug, and thus can be used in anticancer treatment.

The invention relates to a preparation method of a modified magnetic chitosan microsphere heavy metal ion adsorbent, and in particular relates to a modified magnetic chitosan material which has good selectivity and adsorptive property for heavy metal ions in food, and can be recycled, and a preparation method of the modified magnetic chitosan material. Specifically, the invention discloses the preparation method of the modified magnetic chitosan microsphere heavy metal ion adsorbent. The method comprises the steps of preparing magnetic chitosan microspheres by taking chitosan powder as a raw material, further preparing the magnetic chitosan microspheres into hydroxypropyl chlorine magnetic chitosan microspheres, and carrying out chemical grafting on the hydroxypropyl chlorine magnetic chitosan microspheres by taking the hydroxypropyl chlorine magnetic chitosan microspheres as parents and 2-aminothiazole as ligands to obtain the modified magnetic chitosan microsphere heavy metal ion adsorbent. The modified magnetic chitosan microsphere heavy metal ion adsorbent prepared by the method has preferential adsorption for Hg2+ ions.

The invention relates to the technical field of fine and deep processing and utilizing of medicines and aquatic products, and aims at providing a preparation method for preparing cross-linked chitosan microspheres with epoxy chloropropane as a cross-linking agent. The preparation method comprises the steps of: firstly preparing chitosan microspheres by an antiphase suspension method, making partial hydroxy on chitosan molecules to participate in cross-linking reaction with epoxy chloropropane as the cross-linking agent, thus converting linear chitosan molecules into reticular high polymer, and preparing cross-linked chitosan microspheres having a porous reticular structure with calcium carbonate as a pore-forming agent. The cross-linked chitosan microspheres prepared by the preparation method provided by the invention can be biodegraded, have good acid and base resistance, better adsorption effect on acid radical ions and proteins, and strong heavy metal ion loading capacity, and can be applied to foodstuff, medicine chemical industry and other fields.

The invention provides a method for immobilizing trypsinase by chitosan microspheres, which belongs to the technical field of food processing. The invention uses chitosan as immobilizing carriers, and uses a reverse-phase suspension method for preparing the chitosan microspheres after the chitosan is dissolved in an acetic acid solution, then, glutaric dialdehyde is used as a cross linking agent for cross linking activation on the chitosan microspheres, the chitosan microspheres after the cross linking activation are mixed with a trypsinase solution for immobilization, and the immobilized trypsinase is obtained. The trypsinase is one of the enzyme preparations in most common use of protein modification and hydrolysis in food industry. The invention uses the chitosan for immobilizing the trypsinase, so the trypsinase can be used repeatedly, the utilization efficiency of the trypsinase is improved, the enzyme consumption in the protein hydrolysis process and the production cost are reduced, and the invention can be widely used for the hydrolysis process and the modification of protein such as cow milk, meat, aquatic products and the like.

The invention discloses a drug-delivery absorbable hemostatic sponge, which belongs to the technical field of novel hemostatic materials and comprises drug-loaded chitosan microsphere and collagen protein, wherein the drug-loaded chitosan microsphere comprises medicinal grade chitosan and medicinal grade tranexamic acid. The weight ratios of the medicinal grade chitosan to the medicinal grade tranexamic acid are (0.01-100):1 respectively. The invention also discloses a method for preparing the drug-delivery absorbable hemostatic sponge. By selecting collagen with good hemostatic function and biocompatibility as the main hemostatic substrate, compounding the drug-delivery chitosan microsphere and the medicinal grade tranexamic acid, and making use of the special properties of the chitosan including hemostatic function and drug-delivery function, a novel hemostatic sponge with rapid hemostasis and lasting and steady drug delivery in a period of time can be prepared, and has considerable economic and social benefits.

The invention relates to a preparation method of magnetic chitosan microsphere immobilized horse radish peroxidases. The preparation method is used in the fields of enzyme engineering development application and environmental protection, and enzyme can be recycled after enzyme immobilization is carried out. The technical scheme is dissolving polyethylene glycol 4000in water, adding Fe<2+> salt and Fe<3+> salt according to the mass ratio of 1:4, dropwise adding stronger ammonia water until pH of a system is larger than or equal to 10, adjusting the pH to 7.0 by using acetic acid after 2h, and conducting magnetic field separation and washing to obtain magnetofluid; then preparing the acetic acid solution of chitosan magnetofluid according to mass ratio of the chitosan to the magnetofluid of3:1, ultrasonically blending, adding in atoleine containing emulsifier span 80 for emulsifying, adding glutaraldehyde for solidification for 3h, and conducting separation, washing and drying to obtain magnetic chitosan microspheres; and finally adding the magnetic chitosan microspheres in horseradish peroxide enzyme phosphate buffer, solidifying for 3h at 4DEG C, conducting separation, washing and filtering to prepare the magnetic chitosan microsphere immobilized horse radish peroxidases. Carriers of the method are cheap and easy to obtain, enzyme stability is good, and the preparation methodis favorable for rapid and repeated use of the enzyme.

The invention relates to a method for detecting ten types of organophosphorus pesticides by using magnetic separation-gas chromatography. The method is used for quickly detecting ten types of organophosphorus pesticides (dipterex, methamidophos, acephate, omethoate, moncrotophos, dimethoate, phosphamidon, parathion-methyl, malathion and chlorpyrifos) based on combination of solid-phase extraction, magnetic separation and the gas chromatography. The method comprises the following steps: preparing a magnetic solid-phase extraction agent, establishing a combination system of the magnetic separation and the gas chromatography, and detecting the organophosphorus pesticides in objects to be detected. A method capable of quickly separating and detecting ten types of organophosphorus pesticides at high sensitivity simultaneously is established by taking prepared magnetic chitosan microspheres with high absorption performance on the ten types of organophosphorus pesticides such as dipterex and the like as adsorption functional materials and using combination of the solid-phase extraction, magnetic separation and the gas chromatography. The method is simple in experimental operation, high in detection sensitivity, low in cost and applicable to detection of residues of ten types of organophosphorus pesticides such as trace dipterex and the like in all products.

The invention relates to nanometer silver-doped titanium dioxide/chitosan composite microspheres, which is source water cleaning agent. The source water cleaning agent is the composite microspheres prepared by using nanometer silver-doped titanium dioxide as a catalyst and using chitosan as a carrier and is used for treating phenol in source water, wherein the nanometer titanium dioxide is doped with silver, then is mixed with the chitosan, is embedded by polyvinyl alcohol and sodium alginate and is prepared into the nanometer silver-doped titanium dioxide/chitosan microspheres. According to the cleaning agent, the phenol in the source water is effectively reduced, and the removal rate of the phenol in the source water can reach 95.3 percent.

The invention provides a porous magnetic chitosan gel microsphere with controllable particle size based on an in-situ co-precipitation principle and a preparation method thereof. The preparation method comprises the following main steps: firstly, carrying out a complexation reaction on a mixed solution of Fe<2+>, Fe<3+> and chitosan to prepare precursor-induced pre-sol; secondly, dropwise dripping the pre-sol into an alkaline soaking solution containing NaOH, sodium citrate and the like for coprecipitating to generate nano-Fe3O4; thirdly, carrying out a crosslinking reaction on the pre-sol and then curing, wherein the crosslinked chitosan gel microsphere is of a porous reticular structure and the Fe3O4 is uniformly distributed in the chitosan gel microsphere. The particle size of the chitosan gel microsphere is controlled by adjusting the rotating speed of a peristaltic pump and the concentration of the solution. The chitosan gel microsphere prepared by the method has the advantages of abundant pores, large specific surface area, and high adsorption and acid resistance; in addition, the preparation method has the characteristics of simplicity, wide source in raw materials, low cost, easiness in separation and recovery, no secondary pollution and the like. The porous magnetic chitosan gel microsphere disclosed by the invention can be used for enrichment, recovery and contamination remediation of metals in mines, smelting plants, electronic factories, electroplating plants and radioactive wastewater.

The invention provides a chitosan microsphere. The chitosan microsphere comprises, by mass, 25-99% of chitosan and 1-75% of a hydrophilic polymer, and the hydrophilic polymer comprises at least one of polyvinyl alcohol, gelatin, cellulose and polyoxyethylene. The chitosan microsphere improves the moisture absorption capability and the moisture retention capability of chitosan, and solves the problem of traditional powder hemostasis materials. The invention also provides a preparation method of the chitosan microsphere. The method comprises the following steps: mixing a chitosan solution with a hydrophilic polymer solution until the chitosan solution and the hydrophilic polymer solution are uniform in order to prepare a mixed solution; and adding the mixed solution to a negatively charged receiving solution in a dropwise manner through adopting an electrostatic spraying technology, standing to obtain a microsphere suspension, separating to obtain microspheres, washing the microspheres, and drying the washed microspheres to obtain the chitosan microsphere. The preparation method has the advantages of simplicity and mild conditions, and the dimensions of the prepared chitosan microsphere are uniform and controllable.

The present invention discloses preparation process and application in treating hyperbilirubinemia of magnetic adsorbent. The magnetic adsorbent is one kind of polyaminated magnetic chitosan microsphere prepared with (NH4)2Fe(SO4)2.6H2O, NH4Fe(SO4)2.12H2O and chitosan as main material, and sodium hydroxide as precipitant, and through hydroxypropylation and amination. It has hydroxypropyl radical and amino radical introduced into the molecular structure of chitosan, high amino radical content, strengthened alkalinity, reactive functional amino radical and capacity of being separated fast under the action of external magnetic field. It has high adsorption on bilirubin and may be used in treating hyperbilirubinemia.

The invention relates to a Brevendimonas vesicularis strain and application thereof in preparing an immobilized microbial adsorbent. The application method comprises the following steps: carrying out co-culture on a Brevendimonas vesicularis S3 solution and chitosan so that the Brevendimonas vesicularis S3 grows and is adsorbed to the chitosan surface to form an immobilized Brevendimonas vesicularis S3 chitosan composite material, carrying out vacuum filtration, and carrying out low-temperature vacuum drying; adding the obtained microbial composite material into a sodium-alginate-containing water solution, uniformly stirring and mixing, dropwisely adding a calcium chloride solution so that the microbial chitosan composite material is embedded to form sodium alginate microbial chitosan microspheres, washing with water, and airing to obtain the immobilized bacterium microspheres. The Brevendimonas vesicularis S3 is collected by China General Microbiological Culture Collection Center, and the collection number is CGMCC No.11072. The immobilized bacterium microspheres can be used for treating heavy-metal-polluted industrial wastewater, have the advantages of low cost and favorable effect, and are convenient and easy to recycle.

The invention relates to methods of preparing an organic boron compound and a beta-carbonyl compound by catalyzing copper ion loaded chitosan microspheres. The preparation method of the organic boroncompound mainly comprises the following steps of A, adding copper ion loaded chitosan microspheres, tetrahydrofuran and water into a reaction vessel, and fully stirring to obtain a mixed solution under room temperature; B, adding an alpha,beta-unsaturated carbonyl compound and a bis(pinacolato)diboron reagent into the mixed solution; C, stirring at room temperature so as to react fully; and D, after the reaction is finished, separating and purifying to obtain the organic boron compound. The preparation method of the beta-carbonyl compound comprises the steps A, B and C of the above method, andalso comprises steps of directly filtering, then washing with tetrahydrofuran and mixing a washing liquid with a filtrate, adding sodium perborate tetrahydrate into the filtrate, stirring at room temperature so as to react fully, separating and purifying to obtain the beta-carbonyl compound. The methods have the beneficial effects that the copper ion loaded chitosan microspheres are used as a catalyst to prepare the organic boron compound for the first time, no extra ligand is added, and the methods have high catalysis efficiency, high stability, and is non-toxic and environmentally friendly.