251 results about "Crosslinked chitosan" patented technology

The present invention is directed to a biocidal water treatment composition, water treatment apparatus, and method of treating water to reduce levels of pathogens. The composition contains sources of copper, zinc, and silver metal ions within a crosslinked polymer matrix. Examples of these ion sources include copper sulfate, zinc sulfate, and silver nitrate. An example of the crosslinked polymer matrix is crosslinked chitosan, which also serves to clarify the water and release the metal ions over time. The product is easy to manufacture, and allows the use of decreased halogen sanitizer, as well as decreased copper ion, thereby decreasing the likelihood of staining. The product simultaneously provides good bactericidal and algaecidal properties, despite low levels of copper ion and low chlorine levels.

The invention relates to biocompatible, bioabsorbable derivatized non-crosslinked chitosan compositions optionally crosslinked to gelatin/collagen by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) for biomedical use and methods of making and testing such compositions, including a modified acute systemic toxicity test. The compositions comprise derivatized chitosan reacetylated to a degree of N-deacetylation (DDA) of between about 15% and 40%. The compositions are typically bioabsorbed in about 90 days or less and can be made to bioabsorb at differing rates of speed. The compositions are initially soluble in aqueous solution below pH 6.5. The compositions have an acid content that can be adjusted between about 0% (w/w) and about 8% (w/w) to customize the composition for uses that require and/or tolerate differing levels of cytotoxicity, adhesion, composition cohesion, and cell infiltration into the composition.

The present invention concerns multilayer films comprising a plurality of layers, at least some of the layers comprise (i) cross-linked chitosan, alginate, chondroitin sulfate, or hyaluronic acid and (ii) particles or void spaces; wherein the layers are 20-260 nm in thickness. Also disclosed are multilayer films comprising at least two of: a layer comprising a first polymer; a layer comprising a second polymer; a layer comprising particles, wherein said particles comprise ceramic material, metallic species, or both; and, a layer comprising a combination of said first polymer and said particles; wherein said multilayer film is capable of displaying structural color. Also provided are methods for making and using the inventive multilayer films and compositions comprising the multilayer films.

The invention relates to a citric acid-modified cyclodextrin crosslinking chitosan porous adsorption material, and preparation and an application of same. The preparation method includes the steps of: modifying beta-cyclodextrin with citric acid, performing amide crosslinking to a modified beta-cyclodextrin water solution with a chitosan solution under the effect of an EDC/NHS coupling agent, and freeze-drying the product to obtain the modified beta-cyclodextrin crosslinking chitosan porous adsorption material. In the invention, by means of the modified beta-cyclodextrin crosslinking chitosan, the acid resistance of chitosan is improved, and a defect that the chitosan material is liable to dissolve in an acidic solution and is difficult to recycle is overcome. In the invention, hydrogel is freeze-dried, so that chitosan-base porous materials in different shapes can be rapidly produced. The citric acid-modified cyclodextrin crosslinking chitosan porous adsorption material has excellent adsorption capability to anionic dyes; at room temperature, the material can reach 1060.41 mg/g in saturation adsorption quantity to reactive yellow BH-3RS.

The invention provides a PLGA (polylactic acid-hydroxyacetic acid) nano-drug carrier which is composed of PLGA nano microsphere kernel and an anillic aldehyde crosslinked chitosan housing. A preparation method of the polylactic acid-hydroxyacetic acid copolymer nano-drug carrier is as follows: dispersing a PLGA organic phase which takes dichloromethane and alcohol as a mixed solvent in a water phase to prepare PLGA microspheres by taking PVA (polyvinyl acetate) as an emulsifier by virtue of an one-off emulsion process; then, adding the PLGA microspheres into chitosan liquor, so that the chitosan is adsorbed on the surfaces of the PLGA microspheres, and then adding the chitosan on the surfaces of anillic aldehyde crosslinked PLGA microspheres. The product has a certain pH environmental responsiveness, can realize controlled release of the drug according to in-vivo pH environmental changes, is high in stability, strong in up-taking capacity for microsphere-coated medicaments by the cells, and has very good application prospect in the drug carrier for treating tumors.

Microporous glutaraldehyde-crosslinked chitosan sorbents, methods of making and using them, and a generator for the radioisotope ⁹⁹Mo containing the sorbents.

The invention provides a preparation method of a cellulose acetate membrane surface crosslinked chitosan hydrophilic membrane and belongs to the technical field of membrane surface modification. A cellulose acetate membrane is activated by an acid solution, and has coupling crosslinking with the acetic acid water solution of the chitosan, so that a hydrophilic membrane material of the cellulose acetate membrane surface crosslinked chitosan can be prepared. The preparation method of the invention is simple in technology, low in cost, natural, and environmentally-friendly. The cellulose acetate membrane modified by the method is good in hydrophillic nature and binding capability, is good in mechanical strength and mechanical toughness, can be widely applicable to the field of biochemistry, molecular biology and environment, such as the immunoassay, the protein and DNA (deoxyribonucleic acid) analysis, the colloidal gold detection card, the absorption and removal of the toxic and harmful substances in the environment such as the environmental hormone and the like, and can be taken as biomedical material due to the improvement of the mold resistance of a cellulose acetate membrane.

The invention discloses an irradiation crosslinking chitosan/gelatin/polyvinyl alcohol hydrogel dressing as well as a preparation method and an application thereof. The preparation method comprises the steps that a chitosan, gelatin and polyvinyl alcohol solution is prepared by using ultrapure water serving as a solvent; the solution is stirred and mixed uniformly and then irradiated, and original hydrogel is obtained; the original hydrogel is put into the ultrapure water to be soaked; and the chitosan/gelatin/polyvinyl alcohol hydrogel dressing is prepared. The hydrogel dressing is extensive in raw material source, simple in preparation technology and stable in performance, and has the advantages of inflammation diminishing, wound pain relieving, scar reduction, wound healing promotion, wound seepage absorption, and excellent biocompatibility. The hydrogel dressing is easy to degrade after abandoned, and has a smaller influence on an environment. The hydrogel dressing can be applied to the fields of trauma hemostasis, inflammation diminishing, scald, postoperative wound healing and the like.

The invention discloses a chitosan hemostatic material formed through covalent crosslinking and a preparation method thereof. The chitosan hemostatic material formed through covalent crosslinking is obtained by chemically crosslinking chitosan by utilizing a crosslinking agent via covalent bonds, wherein the crosslinking agent is polyethylene glycol diglycidyl ether. The preparation method of the chitosan hemostatic material formed through covalent crosslinking comprises the following steps: 1) preparing chitosan into a water solution; 2) adding the crosslinking agent to the chitosan water solution, fully stirring and mixing the materials, then pouring the mixture into a mold, and freeze-drying the product, thus obtaining the chitosan hemostatic material, wherein the crosslinking agent is polyethylene glycol diglycidyl ether. The chitosan hemostatic material and the preparation method have the beneficial effects that chitosan is crosslinked by polyethylene glycol diglycidyl ether under acidic conditions; an ethylene oxide group in polyethylene glycol diglycidyl ether carries out ring-opening reaction with hydroxyl on chitosan under acidic conditions to form the crosslinked product by generating ether bonds; the crosslinking agent used in the method is relatively safe; the preparation process is simple and practicable and is lower in production cost.

The invention relates to diadehyde starch cross-linking chitosan magnetic microsphere and the preparation method, and the diadehyde starch cross-linking chitosan magnetic microsphere belongs to the functional macromolecule material. The preparation method comprises the following steps: firstly, the diadehyde starch is prepared; secondly, the diadehyde starch cross-linking magnetic microsphere is prepared; and thirdly, the diadehyde starch cross-linking chitosan magnetic microsphere is prepared. The diadehyde starch cross-linking chitosan magnetic microsphere uses the magnetic microsphere prepared through the cross-linking reaction of the chitosan and the diadehyde starch, the magnetic microsphere has no toxic side effect to the human body. The diadehyde starch cross-linking chitosan magnetic microsphere prepared through the invention is used for the targeting drug carrier, and the diadehyde starch cross-linking chitosan magnetic microsphere contains a large quantity of aldehyde groups, which is convenient for the combination of the amino groups in the drug, thereby enhancing the drug carrying amount, and simultaneously after the drug arrives at the lesion location, which can be easily combined with the proteases in the human body, to fully exert the drug effect.. The diadehyde starch cross-linking chitosan magnetic microsphere and the preparation methodare particularly suitable for the treatment to the tumour.

The invention belongs to the technical field of new materials, and particularly relates to a preparation method of a crosslinked chitosan/gelatin composite porous scaffold. According to the method, chitosan, gelatin and other natural biological materials are used as raw materials, an organosilane coupling agent is used as a crosslinking agent, and a freeze-drying process is utilized to prepare the excellent-mechanical-property crosslinked chitosan/gelatin composite porous scaffold composed of pure natural biological materials. The crosslinked chitosan/gelatin composite porous scaffold has the characteristics of high porosity, high pore strength, large pore diameter and the like; the pore size is 100-300 mu m, and the porosity is 90%; and the crosslinked chitosan/gelatin composite porous scaffold is in an open pore structure in which larger pores contains smaller pores, and thus, cells are suitable to be implanted on the scaffold surface. Compared with the chitosan scaffold, the crosslinked chitosan/gelatin composite porous scaffold has better mechanical properties; and the addition of the gelatin and organosilicon crosslinking agent is more beneficial to proliferation and differentiation of cells on the porous scaffold surface, and the crosslinked chitosan/gelatin composite porous scaffold has higher affinity for biological cells.

The invention discloses a crosslinked chitosan-biochar microsphere adsorbing material. The material is prepared from chitosan, biochar powder and a crosslinking agent, and chitosan and the biochar powder are uniformly mixed. A preparation method of the material comprises the steps as follows: firstly, adding chitosan to a diluted acid solution and performing stirring to form sol; then, adding thebiochar powder to the sol and performing stirring to form mixed sol; next, dropping the mixed sol in an alkaline solution to form microspheres; after washing the microspheres to be neutral, soaking the microspheres in a crosslinking agent, and washing the microspheres with deionized water to be neutral after soaking. According to the crosslinked chitosan-biochar microsphere adsorbing material andthe preparation method thereof, the prepared crosslinked chitosan-biochar microspheres have the characteristics of advanced, rough and complex pore structures, have larger specific surface area, havegood adsorption capacity for heavy metal ions and organic dyes in water and can be completely recovered after use, and the secondary pollution problem due to the fact that chitosan and biochar are difficult to recover completely when adsorbed in the form of powder is solved.

The invention discloses a method for preparing a crosslinked chitosan microsphere heavy metal ion adsorbent. The method comprises the following steps of: 1) by taking chitosan as a material and liquid paraffin as an organic dispersing medium, protecting amino on chitosan C2 by using formaldehyde, and by taking epoxy chloropropane as a crosslinking agent, preparing a crosslinked chitosan microsphere by a reversed phase suspension crosslinking method; and 2) by taking the crosslinked chitosan microsphere as a matrix and 2-(chloromethyl)benzimidazole as a ligand, chemically grafting the crosslinked chitosan microsphere to obtain the crosslinked chitosan microsphere heavy metal ion adsorbent. The crosslinked chitosan microsphere heavy metal ion adsorbent prepared by the method has high adsorption speed, can selectively adsorb the Hg<2+> ion highly, can easily and completely desorb ions and can be repeatedly used.

The invention discloses a preparation method of a compound emulsifier in-situ crosslinking chitosan quaternary ammonium salt essential oil microcapsule. A compound emulsifier which has the dual functions of an emulsifier and a cross-linking agent is prepared through double hydroformylation modification on polyethylene glycol; in the preparation process of the chitosan quaternary ammonium salt essential oil microcapsule, on one hand, essential oil is emulsified by a polyethylene glycol long carbon chain structure in the compound emulsifier, on the other hand, chitosan quaternary ammonium salt crosslinking is conducted through a condensation reaction between aldehyde groups at the two ends of the compound emulsifier and amino groups on the chitosan quaternary ammonium salt, and then synchronization of the essential oil emulsifying process and the chitosan quaternary ammonium salt crosslinking process is achieved. According to the preparation method, by grafting aldehyde molecules achieving the chitosan quaternary ammonium salt crosslinking function onto polyethylene glycol, freeing of micromolecular aldehyde in the essential oil microcapsule preparation process is avoided, therefore, the content of micromolecular aldehyde in the essential oil microcapsule product is decreased, and the toxicity of the product is lowered.

The present invention is crosslinked chitosan-quaternized hydrolyzed collagen preparing process and relates to antibiotic biological material preparation. The crosslinked chitosan-quaternized hydrolyzed collagen is prepared with silkworm pupa chitin and hydrolyzed collagen as material. The preparation process includes mixing two kinds of solution, adding crosslinking agent to perform crosslinking reaction, membrane concentration, regulating pH value, and volumetric or spray drying to produce powder. The present invention can prepare solution or sol product and into the product, various water soluble functional factors, such as skin growth factor, moisture maintaining factor, vitamin, etc. may be added to form multifunctional biological dressing.

The invention belongs to the technical field of functional materials, and discloses tannic acid cross-linked chitosan gelatin liquid-absorbing hemostatic antibacterial sponge and a preparation method thereof. The preparation method comprises the steps: carrying out chemical cross-linking on chitosan and gelatin through an esterification reaction to form a primary cross-linking network, and thus obtaining modified super-hydrophilic gelatin; taking tannic acid as a cross-linking agent, and further cross-linking under the action of a strong oxidant to form a secondary cross-linked network; and then adding medical auxiliary materials, hydroxyapatite and sodium alginate to carry out physical mechanical foaming, and carrying out freeze drying to obtain the porous spongy chitosan/gelatin liquid-absorbing hemostatic antibacterial sponge. The spongy porous material obtained by crosslinking tannic acid with chitosan/gelatin is good in mechanical property, porous and fine in structure, soft in surface, wide in raw material source, low in market price, good in biocompatibility, non-toxic and biodegradable, and does not need to be infiltrated in advance when being in contact with a human body; and the preparation method is simple and efficient, is beneficial to large-scale production and has a good market application prospect.

The invention relates to a method for preparing magnetic carbon nanotube/crosslinked chitosan composite nanomaterial adsorbent. According to the invention, a carbon nanotube original sample is adopted as a raw material; the magnetic performance of metal catalyst particles residual in the carbon nanotube original sample and the high-efficiency selective adsorption performance of the carbon nanotube are fully utilized; the adsorption performance of the material is significantly improved through compositing with biological material chitosan; therefore, the magnetic composite nanomaterial adsorbent with high efficiency in adsorbing dye in water phase is obtained. The magnetic composite nanomaterial adsorbent obtained in the invention has the advantages that: the carbon nanotube has no need to adopt strong acid treatment so that the structural integrity of the carbon nanotube is protected; the magnetic performance of the metal catalyst particles residual in the original sample is utilized so that additional process is not needed for composition of magnetic particles; moreover, the crosslinked chitosan has good biocompatibility to benefit the toxicity reduction of nanomaterial and potential biological application; and the obtained nano composite adsorbent can be conveniently and rapidly separated and recycled by adopting magnetic separation technology, so that secondary environmental pollution is avoided.

The invention relates to preparation of water-soluble crosslinked chitosan and application thereof. The preparation comprises the following steps of: with different metal ions as templates, obtaining crosslinked chitosan through dialdehyde molecules by adopting a molecular imprinting technology; and hydriding Schiff base through sodium borohydride, and oxidizing and hydrolyzing by utilizing hydrogen peroxide to obtain the water-soluble crosslinked chitosan. The water-soluble crosslinked chitosan can be used for specifically adsorbing metal ions and applied to enrichment of metals, purification of metals bringing pollution to environment, emission acceleration of metals harmful to the human body as well as the injury treatment and emission acceleration of radionuclide.

The invention discloses a method of using dopamine for rapidly crosslinking chitosan to prepare hemostatic sponge, and belongs to the field of biomedical materials. The dopamine is adopted to react with amidogen on a chitosan chain, and meanwhile a self-polymeric reaction is performed, so that chitosan chain sections are crosslinked to form a cross-linked network structure, and the obtained chitosan sponge has the certain mechanical strength. In the reaction process, the oxidizing agent sodium periodate is added to accelerate the reaction, and therefore the time spent for preparing the chitosan hemostatic sponge can be greatly shortened. The chitosan hemostatic sponge has the good biocompatibility, also has the strong water expansion performance, mechanical performance, water retention and moistening performance and biodegradability, has the good analgesic and hemostatic effects, prevents wound contamination and infection, promotes healing of injured tissue, and can be possibly applied to clinical first aid and hemostasis.

The invention discloses a method for preparing an ultralow pressure fouling resistant composite reverse osmosis membrane through chitosan. The method comprises the following steps: dissolving chitosan with the deacetylation degree above 90 percent in acetic acid, and preparing solution A with the mass concentration of 1 to 10 percent after removing solid impurities in the solution; mixing crosslinking agent solution and hydrochloric acid through stirring to form solution B; and finally mixing solution A and solution B, spreading a mixed solution onto a polyamide carrier membrane, and preparing the ultralow pressure fouling resistant composite reverse osmosis membrane after drying. The obtained ultralow pressure fouling resistant composite reverse osmosis membrane has a crosslinked chitosan layer formed on a polyamide layer, thereby improving the hydrophilicity of the reverse osmosis membrane and the fouling resistance of the reverse osmosis membrane, and saving a great amount of power consumption during the operation with ultralow pressure.

The present invention relates to a mercury-containing wastewater treatment technology field, in particular to an attapulgite-crosslinked chitosan composite adsorbent and its solid-phase synthetic method. The attapulgite-crosslinked chitosan composite mercury adsorbent in the invention is synthesized by the method of adding chitosan and glutaraldehyde in batches. In consideration of the limited solubility of chitosan, batch addition can not only dissolve chitosan, but also minimize the use of organic acid, resulting in less discharge of wastewater and waste gas, which is suitable for large-scale industrial production. The prepared mercury adsorbent can be applied to the removal of mercury ions in the wastewater owing to the excellent adsorptive property and regeneration performance. Meanwhile, the solid-phase synthetic procedure for preparing the mercury adsorbent is simple, easy to handle and environmental-friendly. Moreover, the product cost is greatly reduced due to the use of attapulgite.

The invention discloses a method for preparing a photo-crosslinking chitosan hydrogel film. Biocompatible macromolecular chitosan as an initiator is subjected to chemical modification and introduced with hydroxypropyl and nitrine radicals at the 6-O site and N site respectively to form water-soluble photo-crosslinking chitosan; and the water solution of the photo-crosslinking chitosan is irradiated by ultraviolet light to form chitosan hydrogel so as to obtain the photo-crosslinking chitosan hydrogel film. The photo-crosslinking chitosan hydrogel film formed by a chitosan hydrogel film through ultraviolet light crosslinking by a physical method avoids chemical crosslinking with biological toxicity, improves the biocompatibility of the chitosan hydrogel film, realizes the clinical application of the chitosan hydrogel film, and provides a new path for the clinical application of the chitosan hydrogel film.