1210 results about "Carboxymethyl-chitosan" patented technology

The invention provides an adipose-derived stem cell composition for wound repair as well as a preparation method and application thereof, and belongs to the technical field of stem cells. The method comprises the following steps: adding fetal calf serum, dexamethasone, penicillin, streptomycin, collagen, magnetic particles and a P substance into a DMEM culture medium to prepare a culture medium, performing low-frequency magnetic field culture and separation on adipose-derived stem cells to obtain a stem cell solution, performing embedding to obtain stem cell microspheres, freeze-drying supernate to obtain a paracrine culture substance, and performing freeze-drying on the paracrine culture substance to obtain the adipose-derived stem cells. The adipose-derived stem cell composition for wound repair is prepared by mixing the adipose-derived stem cell with stem cell microspheres, hydroxypropyl methyl cellulose, carboxymethyl chitosan, hyaluronic acid, glycerol and stem cell microspheres, has better effects of implanting into damaged tissues, releasing nutrient substances, promoting neovascularization, regulating oxidative stress and inducing anti-inflammatory response, is beneficial to wound repair, and has a good application prospect. The gel can be converted into a gel phase at the skin epidermis temperature of 35-37 DEG C, components are stabilized, and sustained and controlled release is realized.

The invention discloses application of sodium alginate-carboxymethyl chitosan composite hydrogel in preparation of a biological bacterial fertilizer, the sodium alginate-carboxymethyl chitosan composite hydrogel is used for preparation of the biological bacterial fertilizer, and is further used for preparation of the biological bacterial fertilizer with plant growth-promoting rhizobacteria as an effective component, and the sodium alginate-carboxymethyl chitosan composite hydrogel can be stored for a long time and has a good application prospect. The growth promoting effect is stably exerted. The plant growth-promoting bacteria are effectively wrapped and efficiently delivered through a nanometer means to enhance the growth-promoting effect on crops, the adaptability of the plant growth-promoting bacteria to the acid environment is effectively improved, and the advantage of the plant growth-promoting bacteria for promoting plant growth in acid soil is expanded. The biological bacterial fertilizer is suitable for neutral and acidic environments, and the effects of the biological bacterial fertilizer in the aspects of soil remediation and improvement, crop quality and efficiency improvement, crop stress resistance improvement and the like are fully exerted, so that the purposes of losing weight and improving efficiency are achieved.

The invention provides a hemostatic composition, a preparation method thereof and a hemostatic product. The hemostatic composition is prepared from the following raw material components in parts by mass: 0.01 to 0.5 part of cannabidiol, 10 to 150 parts of tannic acid modified carboxymethyl chitosan and 5 to 250 parts of crosslinked starch. The tannic acid modified carboxymethyl chitosan is prepared from the following raw material components in parts by mass: 45 to 55 parts of carboxymethyl chitosan and 0.5 to 1.5 parts of tannic acid. The cross-linked starch is prepared from the following raw materials in parts by mass: 95 to 105 parts of carboxymethyl enzymolysis starch and 2 to 5 parts of sodium trimetaphosphate. The hemostatic composition has a good hemostatic effect, and when the hemostatic composition is used in hemostatic products, the hemostatic products can have a good hemostatic effect.

The invention provides a bio-based adhesive and a preparation method thereof. Inspired by a spider thread structure, biomass adhesive interface enhancement based on a tannic acid adhesion group is combined with construction of a differential phase separation structure by biomass-induced polylipoic acid depolymerization, and a brand new strategy of adhesion-cohesion synergistic enhancement of the adhesive strength of the adhesive is realized. According to the invention, tannic acid and carboxymethyl chitosan are introduced into a lipoic acid-based adhesive, so that the purpose of synergistically enhancing the bonding performance of the adhesive through adhesion-cohesion is achieved, and the defects of weak cohesion, low bonding strength, poor water resistance, poor moisture resistance and the like of the conventional biomass adhesive are overcome. Benefited from a new strategy of adhesion-cohesion synergistic enhancement, the biomass adhesive has good adhesive strength in various environments and materials. In addition, the biomass adhesive also has the characteristics of biological safety, antibacterial and mildew-proof properties and recoverability, so that the product has wider application and potential compared with the previous product, and has a good application prospect.

The invention relates to the technical field of water treatment, and discloses a modified polyaluminum chloride flocculant and a preparation method thereof.The modified polyaluminum chloride flocculant is prepared from, by weight, 50-65 parts of polyaluminum chloride, 8-12 parts of magnesium silicate, 5-8 parts of carboxymethyl chitosan, 15-25 parts of polyaluminum ferric chloride and 3-5 parts of tea polyphenol; the molar ratio of aluminum ions to iron ions in the modified polyaluminum chloride flocculant is (3-4.5): 1. According to the invention, an inorganic-organic dual-modifier synergistic effect mechanism is adopted to construct a'rigid framework-flexible network 'composite structure, and the structure can significantly improve the adsorption capacity of Pb < 2 + >. Meanwhile, the mechanical property of the flocculating agent is improved, so that the flocculating agent can be applied to a high-turbulence environment.

The invention discloses carboxymethyl chitosan-hyaluronic acid-stem cell exosome eye drops as well as a preparation method and application thereof, and relates to the technical field of eye drops and medical biogel. The carboxymethyl chitosan-hyaluronic acid-stem cell exosome eye drops are prepared from tannic acid modified carboxymethyl chitosan and adipose tissue-derived stromal cell exosome freeze-dried powder, the carboxymethyl chitosan-hyaluronic acid-stem cell exosome eye drops provided by the invention can effectively treat xerophthalmia, and are stable in components, safe and reliable. The three components including the tannic acid modified carboxymethyl chitosan, the hyaluronic acid and the adipose tissue-derived stromal cell exosome coexist, so that the functions of all the components can be fully played, a synergistic effect is achieved, and a better treatment effect on xerophthalmia is achieved.

The invention provides a southern red soil dry land deacidification soil conditioner and a preparation method thereof, and belongs to the technical field of soil conditioners. The preparation method comprises the following steps: embedding bacillus subtilis, bacillus licheniformis and bacillus amyloliquefaciens to prepare bacterial microspheres, adding the bacterial microspheres into gel formed by carboxymethyl chitosan and silk fibroin peptide to prepare sustained-release bacterial microsphere gel, uniformly mixing the sustained-release bacterial microsphere gel with porous silicon dioxide loaded with basalt and charcoal, and drying to prepare the acid-reducing soil conditioner for the southern red soil dry land. The acid-reducing soil conditioner for the southern red soil dry land not only improves the pH value of the soil, but also can loosen the soil and improve the air permeability of the soil to a certain extent, and promotes the absorption of crops to moisture and nutrient elements by improving the physical and chemical properties of the soil, so that the normal growth of the crops is ensured, and the acid-reducing soil conditioner has a wide application prospect.

The invention provides a treatment method of ammonia-nitrogen-containing wastewater, and belongs to the technical field of wastewater treatment. The preparation process comprises the following steps: preparing the wastewater treatment agent; preparing an immobilized microbial compound; and treating the ammonia-nitrogen-containing wastewater. According to the immobilized microbial carrier prepared by the invention, a stable dual-network structure and proper pore channels are formed through the synergistic effect of the polyvinyl alcohol, the carboxymethyl chitosan and the polyurethane; secondary cross-linking significantly enhances the stability of the carrier, optimizes internal pore channels, and is beneficial to attachment and proliferation of microorganisms; after the corn straw biochar is modified by Ca / Al, the specific surface area and functional groups are increased, and the physicochemical adsorption of ammonia nitrogen is enhanced. The three are combined, and ammonia nitrogen in wastewater is efficiently removed through synergism of carrier adsorption and microbial metabolism.

The invention relates to the technical field of wastewater resourceful treatment, in particular to a functional membrane for recycling precious metals in wastewater and a preparation method of the functional membrane. The specific preparation method comprises the following steps: preparing a polyamide spinning solution, carrying out electrostatic spinning on the spinning solution to form a polyamide fiber net, stably combining hollow mesoporous nano silicon dioxide on the fiber net through carboxymethyl chitosan, and grafting an epoxy silane coupling agent on the surface of the hollow mesoporous nano silicon dioxide to obtain the hollow mesoporous nano silicon dioxide fiber net. Finally, adipic dihydrazide is grafted on the hollow mesoporous nano silicon dioxide through a ring-opening reaction. Organic polyamide is used as a film forming substance, the raw material cost is low, the method is suitable for large-scale industrial production, the recovery rate of precious metal ions is high, and the film body has good mechanical strength and can stably operate for a long time.

The invention provides a green and efficient petroleum passivator and a preparation method thereof, and belongs to the technical field of passivators. Carboxymethyl chitosan, phytic acid and beta-cyclodextrin are coupled to prepare a chitosan-phytic acid-cyclodextrin compound, bismuth, lanthanum, cerium and aluminum are compounded, and the green and efficient petroleum passivator is prepared through tannic acid polymerization modification. The prepared green and efficient petroleum passivator is green, safe, non-toxic and efficient, has good capturing and passivating capacity on ions such as iron, nickel and vanadium, greatly improves the activity of a catalyst, prolongs the service life of the catalyst, and has wide application prospects.

The invention discloses a method for preparing a high internal phase emulsion and delivering curcumin by using transglutaminase mediated casein-carboxymethyl chitosan covalent substances, aims to improve the stability and bioaccessibility of curcumin, and belongs to the field of food processing. The method comprises the following steps: firstly, carrying out ultrasonic treatment on sodium caseinate for a certain time, and carrying out transglutaminase cross-linking reaction on sodium caseinate and carboxymethyl chitosan to obtain a casein-carboxymethyl chitosan covalent substance; and then adding the mixture into the curcumin-loaded corn oil according to a certain proportion, and homogenizing to obtain the curcumin-loaded high internal phase emulsion. The emulsion has good interface characteristics and can effectively encapsulate curcumin. The preparation process is simple, efficient, green and environmentally friendly, the prepared high internal phase emulsion has high stability and good biological accessibility, a new technical means is provided for delivery of curcumin, and the high internal phase emulsion has wide application prospects in the field of food.

The invention discloses nano-porous aerogel based on carboxymethyl chitosan as well as a preparation method and application of the nano-porous aerogel, and belongs to the technical field of biomass-based aerogel. The aerogel is prepared from the following raw materials in parts by weight: 2.5 parts of deionized water, 0.075 part of carboxymethyl chitosan (CMC), 0.0075 to 0.0225 part of carboxylated multi-walled carbon nanotubes (C-CNT), 0.01125 part of glutaraldehyde (GA), 0.01 part of poly (3, 4-ethylenedioxythiophene)-poly (styrene sulfonic acid) (PEDOT: PSS) and 10 parts of dimethyl sulfoxide (DMSO). According to the preparation method, CM C is used as a matrix, C-CNT is used as an internal conductive material and a strength enhancing material, hydrogel is formed under the action of a cross-linking agent GA, and CMC / C-CNT aerogel is prepared through directional freeze drying; cMC / C-CNT is taken as a substrate, then PEDOT: PSS is dip-coated to obtain CMC / C-CNT / PEDOT: PSS, the CMC / C-CNT / PEDOT: PSS is taken as an external conductive substance, the CMC / C-CNT / PEDOT: PSS and internal C-CNT form a double-conductive network, aerogel with excellent conductive performance and mechanical performance is prepared, the prepared aerogel is used for preparing an aerogel sensor, and the prepared sensor has high mechanical performance and high electrical performance.

The invention belongs to the technical field of materials, and discloses mildew-proof modified starch-based super absorbent resin as well as a preparation method and application thereof. The mildew-proof modified starch-based super absorbent resin is prepared from the following raw materials in parts by mass: 10 to 20 parts of modified carboxymethyl starch, 2 to 3 parts of quaternized carboxymethyl chitosan, 10 to 15 parts of 2-acrylamido-2-methylpropanesulfonic acid, 15 to 25 parts of acrylamide, 100 parts of acrylic acid, 0.4 to 0.7 part of a redox initiator and 0.05 to 0.15 part of a cross-linking agent. According to the invention, the inherent defects of low mechanical strength, poor salt tolerance, poor stability, easy decomposition, short service life and the like of the starch-based resin are obviously improved, so that the starch-based super absorbent resin with good mildew resistance and more excellent performance can be developed.

The invention discloses a hydrogel dressing with a double-slow-release effect as well as a preparation method and application of the hydrogel dressing. The preparation method of the hydrogel dressing comprises the following steps: firstly, preparing methyl acrylate modified hyaluronic acid capable of being photo-crosslinked, then preparing carboxymethyl chitosan nanoparticles loaded with chlorogenic acid, and finally, mixing the methyl acrylate modified hyaluronic acid and the carboxymethyl chitosan nanoparticles loaded with chlorogenic acid to obtain the hydrogel dressing. The hydrogel dressing embedded with the nanoparticles is obtained in a photo-crosslinking mode. The hydrogel dressing provided by the invention not only has good biocompatibility and mechanical properties, but also plays an anti-oxidation role by removing free radicals in a body, and can effectively kill bacteria such as escherichia coli and staphylococcus aureus to play an antibacterial role. The hydrogel dressing can also reduce excessive inflammatory response in the wound healing process by influencing macrophage polarization, promote chronic wound healing and relieve pain of patients.

The invention discloses a rapid hemostasis powder material for massive hemorrhage. The rapid hemostasis powder material for massive hemorrhage is tannic acid modified carboxymethyl chitosan. The invention also provides a preparation method and application of the rapid hemostasis powder material for massive hemorrhage, and a rapid hemostasis microgel composition containing the rapid hemostasis powder material for massive hemorrhage. The rapid hemostasis powder material and microgel composition for massive hemorrhage have excellent water solubility, hemostasis performance and biocompatibility, have multiple effects of sterilization, anti-inflammation, wound healing promotion and the like, and are beneficial to rapid healing of wound parts after hemostasis.

The invention discloses multifunctional hydrogel for promoting healing of diabetic wounds and a preparation method of the multifunctional hydrogel. The multifunctional hydrogel is prepared from Ti3C2Tx-Ag, paeoniflorin (PF), a gel matrix oxidized konjac glucomannan (OKGM) solution and carboxymethyl chitosan (CMCS). The method comprises the following steps: mixing Ti3C2Tx powder with AgNO3 in deionized water, heating to boiling, adding a proper amount of a sodium citrate solution, reacting to obtain Ti3C2Tx-Ag (TA) powder, and mixing the powder with a paeoniflorin (PF) and oxidized konjac glucomannan (OKGM) solution and a carboxymethyl chitosan (CMCS) solution to prepare the KC-PF-TA hydrogel. The multifunctional hydrogel has excellent photo-thermal antibacterial performance, anti-inflammatory performance and angiogenesis promoting performance, shows a remarkable effect of promoting healing of diabetic wounds through the synergistic effect of Ti3C2Tx-Ag and paeoniflorin, and has good biocompatibility; the multifunctional nano-composite hydrogel disclosed by the invention has great application prospect and value in the field of wound repair materials.

The invention discloses riboflavin photodynamic antibacterial hydrogel for a diabetes wound dressing as well as preparation and application of the riboflavin photodynamic antibacterial hydrogel, and belongs to the technical field of biomedical materials. The hydrogel is prepared from carbomer 941, rhizoma bletillae polysaccharide and carboxymethyl chitosan through physical and chemical bi-crosslinking, glutaraldehyde and carboxymethyl chitosan are added to form dynamic imine bonds, and the stability and adaptability of the hydrogel are enhanced. Meanwhile, the photosensitizer riboflavin is introduced, so that the hydrogel is endowed with photodynamic sterilization characteristics, efficient antibiosis is realized, and rapid healing of diabetic wounds is promoted. The hydrogel has excellent wound environment adaptability and adhesion performance, and is suitable for complicated wound surfaces of diabetes mellitus. The successful research and development of the invention provide reference for the development of novel photodynamic wound dressings, have wide application prospects, provide better treatment choices for diabetics, and are helpful for accelerating wound healing, reducing infection risks and improving the life quality of patients.

The invention discloses pH-responsive nanocellulose hydrogel and a preparation method and application thereof, and belongs to the technical field of hydrogel materials.The preparation method of the hydrogel comprises the following steps that firstly, an aldehyde cellulose nanofiber suspension and a carboxymethyl chitosan solution are mixed and stirred for 1-12 h at the temperature of 25-90 DEG C, and the molar ratio of amino to aldehyde is 1: 5-5: 1; 2, tannic acid and curcumin conjugated chitosan are added into the mixed solution of the aldehyde cellulose nanofibers and the carboxymethyl chitosan, the concentration of the tannic acid is 1-10 mg / mL, the concentration of the curcumin conjugated chitosan is 0.5-5 mg / mL, mixing and stirring are conducted, a cross-linking reaction is conducted, and the pH-responsive nanocellulose hydrogel is obtained. Based on the Schiff base bond effect in the hydrogel, the hydrogel has remarkable pH responsiveness, and by means of the hydrogen bond combination effect and synergistic effect among tannic acid, curcumin and nanocellulose, the hydrogel has good mechanical performance and antibacterial performance.

The invention discloses a phosphorus removal adsorbent based on micro-nano air flotation coupling micro-flocculation and a preparation method thereof, and the preparation method comprises the following steps: dissolving carboxymethyl chitosan, mixing with modified hydroxyapatite and a hydrophobic MOF polymer, and polymerizing under the action of an initiator to obtain composite hydrogel; curing the composite hydrogel in a calcium chloride solution, and performing circulating freezing-unfreezing physical crosslinking to obtain the phosphorus removal adsorbent. The organic phosphorus adsorbent and the inorganic phosphorus adsorbent are combined, the phosphorus adsorption capacity of the phosphorus removal adsorbent is enhanced, the hydrophobic MOF polymer with the adsorption effect on hydrophobic new pollutants is uniformly compounded with the organic phosphorus adsorbent, the phosphorus removal adsorbent also has the adsorption effect on insoluble new pollutants in wastewater, and the phosphorus removal adsorbent has the adsorption effect on insoluble new pollutants in wastewater. Under the synergistic effect of the micro-nano air flotation technology, new pollutants adsorbed by micro-nano air flotation are adsorbed by the phosphorus removal adsorbent, and the problems that the binding force of micro-nano air flotation to the new pollutants is low, and the new pollutants are prone to falling off are solved.

The invention discloses an antibacterial bamboo joint pull rope material for tampons and a preparation method of the antibacterial bamboo joint pull rope material. Modified bentonite is introduced into an acrylic acid-acrylamide polymer, and a layered structure of the bentonite endows the antibacterial bamboo joint pull rope material with certain water absorption and water retention capacities; meanwhile, amino groups on the modified bentonite are chemically combined with carboxyl groups in the acrylic acid-acrylamide polymer, so that the modified bentonite is not easy to lose; according to the preparation method, firstly, water-absorbing fibers are soaked in a carboxymethyl chitosan solution, the surfaces of the water-absorbing fibers are coated with carboxymethyl chitosan, the carboxymethyl chitosan has excellent water-retaining and antibacterial properties, an antibacterial water-retaining layer is formed on the surfaces of the water-absorbing fibers, and then under the action of a cross-linking agent ethylene glycol diglycidyl ether, the antibacterial water-retaining layer is formed on the surfaces of the water-absorbing fibers. Hydroxyl groups and amino groups in the carboxymethyl chitosan and carboxyl groups and amino groups on the water-absorbing fibers are subjected to a cross-linking effect, so that the bonding strength and the cross-linking density between the carboxymethyl chitosan and the water-absorbing fibers are improved, liquid seepage is effectively prevented, and the water retention performance of the fiber material is further improved.

The invention relates to the technical field of biomedical materials, and discloses an electret electrostatic therapy membrane and a preparation process thereof.The electret electrostatic therapy membrane is prepared from, by mass, 15%-20% of fluorinated polyether ester, 10%-20% of a composite nano-fiber material, 10%-20% of a composite nano-fiber material, 10%-20% of a composite nano-fiber material and the balance water. 1%-2% of carboxymethyl chitosan; 2-5% of nano cerium oxide particles with the particle size of 50-100 nm; 0.5-1.0% of graphene quantum dots, the particle size of which is 5-10 nm; 1%-2% of sodium hyaluronate; the components are prepared into a film through an electrostatic spinning method, electret performance is given to the film through a charge injection process, finally, the film body is attached to a flexible silica gel adhesion layer, and the flexible silica gel adhesion layer is externally coated with a peelable protective film so that the structural integrity can be kept before the flexible silica gel adhesion layer is used. The composite membrane body disclosed by the invention shows excellent adhesion, charge activation capability and thermal response performance in applications of electrostatic therapy, dielectric assisted stimulation and the like, and has good multi-scene adaptability and clinical application potential.

The invention relates to a PPR antibacterial pipeline and a preparation method thereof, and belongs to the technical field of pipeline processing. The sea-buckthorn extract is used as an auxiliary medium, green synthesis of the silver nanoparticles can be promoted, use of traditional toxic reducing agents and stabilizing agents is avoided, natural active ingredients contained in the sea-buckthorn extract and the silver nanoparticles generate a synergistic effect, the antibacterial efficiency is remarkably enhanced, and the dosage and biotoxicity of the silver nanoparticles are reduced. Meanwhile, the nano silicon dioxide is added, so that the coating can be kept stable in a high-temperature environment. The carboxymethyl chitosan endows the pipeline with excellent antibacterial performance, and forms a synergistic effect with the silver nanoparticles, so that the antibacterial ability of the pipeline is further enhanced. Through the modification of the silane coupling agent KH560, the interface bonding force between the nano silicon dioxide and carboxymethyl chitosan and the interface bonding force between the nano silicon dioxide and the main component PPR of the pipeline are enhanced, so that the reinforcing agent can be more uniformly and stably dispersed in a PPR matrix, and the overall performance of the pipeline is improved.

The invention discloses injectable hydrogel for photo-thermal adjuvant therapy of periodontitis and a preparation method, and belongs to the technical field of high polymer material preparation, the preparation method comprises the following steps: reacting MXene dispersion liquid with epigallocatechin gallate and MgSO4; then sequentially carrying out ultrasonic treatment, centrifugation, washing and freeze-drying to obtain a multifunctional nanosheet MP-Mg; adding the multifunctional nanosheet MP-Mg into an oxidized gellan gum aqueous solution, and carrying out a mixed reaction to obtain a solution A; mixing the quaternary ammonium salt chitosan aqueous solution and the carboxymethyl chitosan aqueous solution in equal volume, and reacting to obtain a solution B; and mixing the solution A and the solution B in equal volume for reaction. The hydrogel prepared by the preparation method disclosed by the invention has injectability, photo-thermal responsiveness, biological membrane penetrability, synergistic antibacterial property and long-acting anti-inflammatory property, and an innovative and practical photo-thermal adjuvant therapy platform is provided for clinical treatment of periodontitis.

The invention discloses a preparation method of a multifunctional polyvinyl composite film and application of the multifunctional polyvinyl composite film in food preservation. The preparation method comprises the following steps: firstly, preparing Ag-coated MOF through a hydrothermal method, then uniformly dispersing the Ag-coated MOF and tannic acid into a carboxymethyl chitosan solution, and carrying out crosslinking modification on the Ag-coated MOF; and coating the prepared CMCS / TA / Ag (at) MOF mixed solution on a polyethylene film treated by oxygen plasma, and drying to form a film, so as to obtain the multifunctional polyethylene-based composite film. The CMCS and the TA are adopted to perform crosslinking modification on the Ag-coated MOF, so that the stability of the Ag-coated MOF can be further improved, and the release of silver ions is reduced. Compared with a common PE preservative film, the composite film prepared on the basis has better barrier capacity and mechanical property, and has antibacterial, anti-ultraviolet and anti-oxidation effects. The multifunctional preservative film is convenient to use and low in price, and has an important application prospect in the aspect of fresh-keeping packaging of meat products.

The invention relates to daily chemical and pharmaceutical industries, in particular to a guanidyl-containing carboxymethyl chitosan quaternary ammonium salt derivative as well as a preparation method and application thereof. The chemical structural formula of the guanidyl-containing carboxymethyl chitosan quaternary ammonium salt derivative is shown in the specification. The prepared guanidyl carboxymethyl chitosan-containing quaternary ammonium salt derivative has good antioxidant activity and can be applied to preparation of an antioxidant, the preparation method is simple, convenient and efficient, the biological activity of chitosan is enhanced, the application range of chitosan is widened, and the guanidyl carboxymethyl chitosan-containing quaternary ammonium salt derivative can be widely applied to the fields of cosmetics, functional food and medicine. # imgabs0 #

The invention discloses a near-infrared responsive injectable MXene / fibroin / carboxymethyl chitosan / oxidized hyaluronic acid nano composite hydrogel SCO (at) M, and relates to the technical field of biomedical materials. The method disclosed by the invention comprises the following steps: 1) preparing an MXene single-layer nanosheet by adopting LiF-HCl in-situ HF etching; (2) modifying the fibroin through glycidyl methacrylate to obtain SF-MA; 3) oxidizing hyaluronic acid with sodium periodate to obtain oxidized hyaluronic acid OHA; (4) uniformly dispersing MXene in the SF-MA solution, and sequentially adding carboxymethyl chitosan CMCS and OHA, so as to prepare the injectable nano composite soft hydrogel with the shear thinning characteristic; and 5) through ultraviolet irradiation crosslinking, rapid in-situ curing of the hydrogel is realized, and the mechanical strength of the hydrogel is improved. The hydrogel provided by the invention has excellent injectability and mechanical property, has good photo-thermal antibacterial property, oxidation resistance and cell compatibility, can be used as a carrier of cells, medicines and bioactive substances in the field of biological medicines, and has a wide application prospect.

Disclosed is preparation of dual cross-linked zein-carboxymethyl chitosan nanoparticles for improving the thermal stability of polyphenol. After covalently cross-linked zein, tannic acid is used to prepare tannic acid cross-linked zein-carboxymethyl chitosan nanoparticles loaded with quercetin, Ca2+ is then added to increase a degree of crosslinking between the tannic acid and the carboxymethyl chitosan, as well as between molecules of the carboxymethyl chitosan in the zein nanoparticles to make the structure tighter, such that structural stability of the nanoparticles can be maintained during the thermal processing after the nanoparticles are formed, the quercetin encapsulated inside is protected well, and a retention rate of quercetin during the thermal processing is improved. The method provided in the present disclosure is simple, green, pollution-free and low energy consumption, and the prepared nanoparticles can improve the thermal stability of quercetin, and can be used as a natural additive for thermal processing of food.

The invention discloses a preparation method and application of photo-thermal antibacterial hydrogel for MRSA (Methicillin Resistant Staphylococcus Aureus) infected diabetes wounds, and relates to the technical field of biological tissue engineering. The method comprises the following steps: uniformly dispersing ZIF-8 (at) PDA nanoparticles in a carboxymethyl chitosan solution, adding a gelatin solution, uniformly mixing, adding into an oxidized sodium alginate solution, and carrying out a Schiff base reaction to obtain the photo-thermal antibacterial hydrogel for MRSA infected diabetes wounds. The hydrogel disclosed by the invention is prepared by crosslinking carboxymethyl chitosan, gelatin, oxidized sodium alginate and dopamine modified ZIF-8 nanoparticles through a Schiff base bond. Carboxymethyl chitosan (CMCS) has excellent biocompatibility, antibacterial activity and adjustable and controllable mechanical properties, and can effectively preserve moisture, form a breathable and moist environment and promote skin healing.

The invention belongs to the field of oilfield chemistry, and discloses development and a method of a gel breaker for recycling drilling fluid, and the preparation method comprises the following steps: (1) contacting chitosan with a modifier under an alkaline condition for chemical modification to obtain O-carboxymethyl chitosan; and (2) carrying out radical polymerization on the obtained O-carboxymethyl chitosan and a quaternary ammonium salt monomer in an acid environment under the action of an initiator to obtain the gel breaker.

The chitosan hydrogel disclosed by the invention is prepared from the following components in parts by weight: 6 to 15 parts of carboxymethyl chitosan, 0.4 to 1 part of a cross-linking agent and 300 to 900 parts of water. The invention belongs to the technical field of polymer hydrogel, and particularly relates to chitosan hydrogel and a preparation method thereof, the prepared chitosan hydrogel is low in toxicity and safer, a low-temperature and high-temperature step-by-step cross-linking product is adopted, compared with a one-step cross-linking product, the residual amount of a cross-linking agent is lower, a chitosan solution and the cross-linking agent react slowly under the low-temperature condition, and the cross-linking effect is good. The mixing is more sufficient under a liquid condition.