276 results about "Cross linked hydrogels" patented technology

The present invention is directed to methods of cryopreserving cells and cryopreserved cells prepared according to the methods. In specific embodiments, the method comprises combining cells with a cross-linked hydrogel matrix in particulate form, the matrix comprising a polyglycan cross-linked to a polypeptide and subjecting the combination to cryopreservation conditions. In further embodiments, the invention provides cell-seeded compositions comprising cells and a cross-linked bioactive hydrogel matrix in particulate form, the matrix comprising a polyglycan cross-linked to a polypeptide, wherein the composition has been subjected to cryopreservation conditions. The cryopreserved cells can be thawed and used in methods of treatment without the need for intervening steps to make the cells viable for in vivo use.

The invention relates to chemical / ionic / physical compounding cross linking hydrogel and a preparation method thereof. The hydrogel is polymerized in a way that olefin monomer M1, a chemical cross-linking agent M2, multivalent ion biomacromolecule M3, an ionic cross-linking agent M4 and a physical cross-linking agent M5 are dissolved in water. The method comprises the following steps: preparing chemical / physical cross linked gel prepolymerization liquid, preparing chemical / ionic / physical cross linked gel prepolymerization liquid and preparing and purifying chemical / ionic / physical compounding cross linked gel. According to the invention, the characteristics and properties of the chemical cross-linking agent, the physical cross-linking agent and the ionic cross-linking agents are taken into consideration comprehensively, the compounding cross linking of molecular chains is realized; the prepared hydrogel is optically transparent and has higher mechanical ductility and rebound elasticity; the mechanic, optical and thermal performances and other performances can be regulated conveniently by controlling technology parameters and conditions; and the prepared hydrogel can be used in the fields such as tissue engineering, food industry, agricultural irrigation, daily chemical engineering, oil production, dye adsorption and biological medicine.

A method of preparation of a cross-linked hydrogel by graft copolymerisation, said method comprises the steps of preparing an aqueous solution comprising one or more hydrophilic polymers, a cross-linking agent and a photoinitiator comprising a water-soluble peroxydisulphate, subjecting said solution to irradiation and obtaining the cross-linked hydrogel, wherein the hydrophilic polymers are saturated and the cross-linking agent acts as a co-catalyst of cross-linking. The hydrogel is fast to produce and has low toxicity. The hydrogel may be suitable for use in medical devices such as dressings and the like.

The present invention provides hydrogel coated, implantable medical devices and methods of coating hydrogels onto implantable medical devices. In one embodiment, a hydrogel coated medical device is formed by physically treating a surface of the medical device, chemically treating the surface, applying a hydrogel precursor and then crosslinking the hydrogel precursor to form a hydrogel coating on the surface of the medical device. The present invention may be particularly applicable for coating articulating surfaces on implantable medical devices such as artificial joints.

The invention discloses a chemical and ionic cross-linked alginate hydrogel flat membrane for filtration, which is designed and prepared aiming at the problems of poor stability, low mechanical strength, overlarge pores and the like of a pure ionic cross-linked hydrogel filtering membrane. According to the flat membrane, sodium alginate is used as a membrane forming substrate, a water-soluble compound is used as a pore-forming agent, and a chemical cross-linking agent and an ionic cross-linking agent are added, so that the sodium alginate is subjected to covalent bonding and ionic cross-linking to improve the stability of the membrane. The mechanical strength and the pore size of the membrane and the stability in an electrolyte solution are adjusted by changing the types and the proportions of the chemical cross-linking agent and the ionic cross-linking agent. The hydrogel flat membrane is prepared through a simple preparation process and is low in cost; no organic waste liquid is produced; the obtained hydrogel membrane can resist the pressure of 0.2-1 MPa and has a good application prospect in the separation field in which membrane pollution is easy to produce, such as oil-water separation, protein separation and biological sample filtration. The hydrogel flat membrane is directly discarded and can be fully degraded by microorganisms after being used, so that no environmental harm is caused.

Disclosed herein is a fibrous tissue sealant in the form of an anhydrous fibrous sheet comprising a first component which is a fibrous polymer containing electrophilic or nucleophilic groups and a second component capable of crosslinking the first component when the sheet is exposed to an aqueous medium, thereby forming a crosslinked hydrogel that is adhesive to biological tissue. The fibrous tissue sealant may be useful as a general tissue adhesive for medical and veterinary applications such as wound closure, supplementing or replacing sutures or staples in internal surgical procedures, tissue repair, and to prevent post-surgical adhesions. The fibrous tissue sealant may be particularly suitable for use as a hemostatic sealant to stanch bleeding from surgical or traumatic wounds.

The present invention relates to crosslinked polymers, synthesized through ring-opening polymerization of ethylenically unsaturated epoxides, in combination with α-hydroxy acids using a hydrophilic macroinitiator, such as poly(ethylene glycol), to form substituted copolymers having ethylenically unsaturated functionality randomly distributed along the polyester polymer backbone. That copolymer is subsequently crosslinked to form a hydrogel network. More particularly, the present invention relates to the synthesis of biodegradable poly(α-hydroxy acid-co-glycidyl methacrylate)-block-poly(ethylene glycol)-block-poly(α-hydroxy acid-co-glycidyl methacrylate) copolymers, which are subsequently crosslinked to form hydrogel networks. The invention also relates to the use of these hydrogel networks in various applications, in particular, for the controlled release of drugs and proteins.

The invention belongs to the field of biomedical engineering materials, and discloses a loaded chitosan (CS) / sodium alginate (SALG) double-crosslinking hydrogel with a colon target and a preparation method and an application thereof. In the invention, the hydrogel is firstly crosslinked with chitosan and then with sodium alginate, the medicine is wrapped in the chitosan, the sodium alginate is coated on the outer layer, and then double crosslinking is performed by the calcium ion and glutaraldehyde, the carboxy and amine are both fixed to form an interpenetrated network, and such a structure is not easy to be degraded and not easy to lose in the body fluid of human beings. After medicine loading, a small amount of medicine can be released after two hours in the gastric juice, and nearly no medicine is released after 4 hours in the intestine, while more medicine is released in the colon, and long-time release can be realized, which makes up the medicine burst release, medicine leakage and easy degradation and loose of materials reflected by the loaded gel prepared in the above, and colon targeting positioning and long-time release of medicine for treatment can be realized.

A method for protecting an entity from the effects of an explosion or from the effects of contact with a projectile by covering at least a part of the entity in a barrier which includes a cross-linked water gel.

The invention relates to a chitosan modified alginate hydrogel three-dimensional porous bracket with specific in-vitro degradability and a preparation method thereof. The method comprises the following steps: dissolving sodium alga acid serving as a raw material in phosphate buffer solution; performing amidation reaction of a carboxyl group in the sodium alga acid and an amino group in a cross-linking agent cystamine or dimethyl cystinate under the activation of water-soluble carbodiimide to form a chemically crosslinked hydrogel; performing freeze drying on the hydrogel to obtain a porous bracket material of the hydrogel; and performing surface modification on the porous bracket by using chitosan. In solution of a reducing agent such as cysteine with an appropriate concentration, a disulfide bond in a hydrogel cross-bridge is degraded through a disulfide bond-sulfydryl conversion reaction, so the porous bracket is decomposed and dissolved and disappears. Therefore, the porous bracket can be used as an in-vitro cell culture template material. The hydrogel porous bracket researched by the invention has the characteristics of simple preparation, rich raw material source, low cost and availability. Various physiochemical performances, mechanical strength, degradation rate and surface properties of the bracket material are controllable within a large range.

The present invention provides methods of promoting the revascularization and / or reenervation of central nervous system lesions using an in-situ crosslinkable hydrogel.

The invention relates to a preparation method of a hydrogel rapidly crosslinked by enzyme catalysis, and application thereof. A precursor of the hydrogel consists of a mixture (hereinafter referred to as No. 1 solution) of good-biocompatibility macromonomer aqueous solution with an active phenolic hydroxyl unit and dioxygenase aqueous solution which is taken as a catalyst, and the aqueous solution of the precursor can rapidly react to form a 3D polymer cross-linked network after an oxidant (usually low-concentration oxydol, hereinafter referred to as No. 2 solution) is injected. As the No. 1 solution and the No. 2 solution have low-viscosity characteristic, are suitable for being transported and injected, and can rapidly crosslink to form a gel network, the hydrogel can be used for vascular embolization treatment, cancer treatment, family planning operation blocking agents, injectable tissue engineering scaffold materials, soft tissue fillers of human body, controlled release drug carriers, anti-adhesive membranes used in operations and the like after adding one or a plurality of components with specific properties to the No. 1 solution or the No. 2 solution or the gel network.

The invention belongs to the technical fields of biotechnology, biological medical materials and tissue engineering, in particular to injected chemical crosslinking protein / polypeptide hydrogel and a preparation method thereof. The injected chemical crosslinking protein / polypeptide hydrogel consists of natural or synthesized protein / polypeptide with a crosslinking phenolic hydroxyl group, horse radish peroxidase and hydrogen peroxide which quickly form the chemical crosslinking hydrogel under physiological condition. The protein / polypeptide hydrogel has good biocompatibility and easily regulated mechanical strength, and is degradable, and the degraded product is amino acids capable of being absorbed by a human body. In addition, the framework of the protein / polypeptide hydrogel very approaches a protein three-dimensional network which supports the cell growth in extracellular matrix, and the invention can be widely applied to multiple biological and medical fields such as drug controlled-release carriers, cell culture supports and the like.

The invention discloses 3D-printed hydrogel wound dressing with a long-acting antibacterial effect. Raw materials for nanosilver reduction include sodium alginate and silver nitrate; raw materials forhydrogel construction include polyvinyl alcohol, carboxymethyl chitosan / chitosan, sodium alginate and deionized water; calcium chloride is adopted as a raw material for hydrogel cross linking. A preparation process includes: (1) preparing nanosilver-sodium alginate solution; (2) preparing polyvinyl alcohol / carboxymethyl chitosan / sodium alginate solution; (3) preparing to-be-printed solution; (4)performing 3D printing of hydrogel on a nonwoven fabric; (5) subjecting a sample prepared in the step 4 to cross linking (freezing-unfreezing and soaking in calcium chloride) to obtain the sodium alginate antibacterial hydrogel wound dressing. The sodium alginate antibacterial hydrogel wound dressing meets requirements of ideal dressing.

The invention belongs to the fields of high polymer materials and medical equipment and relates to a submucous injection material composed of physical cross-linked hydrogel and an application thereof to preparing injection materials for endoscopic submucosal dissection. The submucous injection material consists of an amphiphilic block copolymer, a solvent which takes water as a main body, and a coloring indicator, wherein the amphiphilic block copolymer is formed by taking polyethylene glycol (PEG) as a hydrophilic block and taking degradable polyester as a hydrophobic block. The material has thermal induced gel-forming properties; when the temperature is lower than a sol-gel transition temperature, a water system presents low-viscosity solution, has good injectable property, and can be subjected to endoscopic injection to the submucosal position so as to spontaneously form in-situ physical hydrogel under the body temperature, good gel morphology is maintained during an ESD operation, the uplift height and duration of the submucous injection material are superior to those of an existing pure liquid material, and the ESD operation is smoothly performed.

The invention discloses a preparation method of hyaluronic acid / gelatin / chondroitin sulfate bone repair bionic scaffold. The method comprises the steps of adding activator and furfurylamine into MES buffer solution of hyaluronic acid to obtain modified hyaluronic acid solid; adding EDC / NHS (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide / N-hydroxysuccinimide) into gelatin aqueous solution, and adding furancarboxylic acid to obtain modified gelatin solid; dissolving the above two solids into MES buffer solution to obtain a mixed solution; dissolving MAL-PEG-MAL (maleimide-polyethylene glycol-maleimide) into MES buffer solution, adding into the mixed solution, and reacting in 37 DEG C water bath to form transparent cross-linked hydrogel; soaking the hydrogel in MES buffer solution of sodium chondroitin sulfate, adding EDC / NHS, and reacting under stirring to obtain the cartilage repair bionic scaffold. The bionic scaffold has the advantages of interpenetrating network structure, excellent biocompatibility and bioactivity, better compression strength, anti-washout property and degradability, simple preparation process, and easy operation.

The invention discloses a decomposable temperature-sensitive chemical crosslinking gel and making method in the macromolecular material technical domain, which is characterized by the following: adopting PEG as hydrophilic block and decomposable polyester as hydrophobic block to form the host of temperature sensitive amphipathy block copolymer; forming gel under human body temperature (or normal temperature) in the water; using macromolecular monomer technique to obtain stable chemical crosslinking gel as drug slow-release carrier or culture rack of tissue engineering cell.

The invention belongs to the technical field of macromolecular materials and medicaments, and relates to a physical cross-linking hydrogel composition and a preparation method and application thereof. The composition is a mixture of two or more polymers, and the aqueous system of the composition has the temperature-sensitive reversible gelling property; when the temperature is lower than a sol-gel conversion temperature, the mixture can be dissolved in water; and when the temperature is higher than the sol-gel conversion temperature, the aqueous solution of the mixture forms gel, and the process is reversible, wherein the polymers comprise a block copolymer consisting of polyethylene glycol serving as a hydrophilic block and degradable polyester serving as a hydrophobic block. The aqueoussolution of the composition can be applied to warm-blooded animals through non-stomach intestinal tract, eye, subcutaneous, muscle, vagina, urethra, nasal cavity or lung, forms gel at physiological related temperature, and also can be applied in a gel form. The release speed can be regulated by changing the mixing proportion, polymer composition, molecular weight and polydispersity.

The invention relates to a preparation method, a raw material, a product and an application of an optical coupling crosslinking hydrogel material. Component A-nitrobenzyl phototrigger modified high-molecular derivatives are dissolved in a medium with biological compatibility in order to obtain a solution A; component B-primary amine, diamine, hydrazide, hydroxylamine high-molecular derivatives aredissolved in a medium with biological compatibility in order to obtain a solution B; the solution A and the solution B are uniformly mixed in order to obtain a hydrogel precursor solution; the hydrogel precursor solution is under light source irradiation, aldehyde group or ketone group generated by nitrobenzyl in the component A and primary amine, diamine, hydrazide, hydroxylamine groups in the component B are crosslinked in form of Schiff base in order to form a hydrogel. The invention also provides a kit for preparation of the hydrogel, and applications of the hydrogel to tissue engineering, regenerative medicine, 3D printing, and carriers of cells, proteins or drugs. The hydrogel precursor solution is sprayed or smeared on the surface of tissue in order to realize in situ gelation under light, and the product is especially suitable for postoperative wound enclosing and tissue fluid leakage sealing.

The invention relates to a preparation method of injectable double-cross-linked hydrogel for tissue engineering, which comprises the following steps that: an aqueous solution of aminated gelatin, an aqueous solution of aldehyde dextran, and an aqueous solution of terminated vinyl poly ethylene glycol are mixed according to a volume ratio of 4:4:3, then are cross-linked for 10-20 minutes at a temperature of 35 to 40 DED C, and finally are cross-linked for 3 to 8 minutes by ultraviolet irradiation. The preparation method provided by the invention has a simple operation process and mild implementation conditions; and the double-cross-linked hydrogel obtained by the invention is non-toxic and biodegradable, has good mechanical properties and biocompatibility, and can be used for injectable hydrogel scaffold in the tissue engineering.

Embodiments of the invention generally provide pharmaceutical drug compositions, methods of preparing oral drug compositions, such as controlled release dosage compositions for hydrophobic active ingredients. In one aspect, the invention provides a pharmaceutical formulation comprising a therapeutically effective amount of a hydrophobic drug, an adjustable ratio of a non-cross linked hydrogel polymer and a non-gelling insoluble polymer. One example is a controlled release pharmaceutical composition which includes 1% to 80% of a therapeutically amount of cilostazol, 4% to 80% of a water-swelling hydrogel polymer, and 4% to 80% of a non-gelling insoluble polymer. In another aspect, a constant release profile of the pharmaceutical formulation is obtained. In another aspect, a zero degree release profile of the pharmaceutical formulation is obtained. Further, a method for treating intermittent claudication using the pharmaceutical formulation is provided.

The present invention provides methods of promoting the revascularization and / or reenervation of central nervous system lesions using an in-situ crosslinkable hydrogel. The present invention also provides methods of treating a spinal cord injury by topically delivering to the spinal cord injury site a vehicle comprising a neurotrophic factor and / or anti-inflammatory agent. Also provided are methods of treating a spinal cord injury by topically administering or delivering a hydrogel to the injury site.

The invention relates to injectable silk fibroin-alginate double cross-linking hydrogel which comprises a solution A: a silk fibroin solution and a solution B: a modified alginate solution, wherein the solution A comprises the following components in parts by weight: 1.0*10<-1>-3.0 parts of silk fibroin, 1.4*10<-3>-2.0*10<-3> part of a divalent metal ion cross-linking agent, and the balance of water containing 1-5wt% of silk fibroin; the solution B comprises the following components in parts by weight: 5.0*10<-1>-4.0 parts of alginate, 2.5*10<-3>-4.0*10<-1> part of a carboxyl activating cross-linking agent and the balance of water containing 1-5wt% of alginate. By adopting a double cross-linking method of covalent cross-linking and ion cross-linking, the double cross-linking hydrogel is quick to polymerize in situ and has an application prospect in the fields such as engineering stents, drug controlled release and regenerative medicines. The invention further provides a preparation method and a use method of the double cross-linking hydrogel.