175 results about "Cystamine" patented technology

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 invention discloses a method for re-crystallizing, refining and purifying sugammadex sodium. The method comprises the following steps: adding a protective agent to crude sugammadex sodium, and performing re-crystallizing under the protection of an inert gas to obtain pure sugammadex sodium, wherein the protective agent is selected from one or a mixture of two or more of mercaptoethanol, mercaptoacetate, mercaptoacetate ester, mercaptopropionate, mercaptopropionate ester, glutathione, cysteine, cystamine, dithioerythritol, dithiothreitol, trisubstituted organophosphorus compounds and trisubstituted organophosphorus compound salts. The method has the advantages of simplicity in operation, high product purity, good economy, and suitableness for industrial production.

The invention discloses a multi-stimuli responsive shell crosslinked polymeric micelle and a preparation method thereof. The polymeric micelle is prepared by: carrying out ATRP and click chemistry reaction to synthesize an amphiphilic diblock polymer with polydimethylaminoethyl methacrylate (PDMAEMA) as the hydrophilic chain and polymethacrylate ferrocenyl formyloxy ethyl ester (PMAFFEE) as the hydrophobic chain, subjecting the polymer to self-assembly in water to form core-shell micelles with uniform size, and then carrying out cross-linking reaction on the micelles and N, N'-di(bromoacetyl)cystamine. The core-shell crosslinked polymeric micelle provided by the invention is responsive to temperature, pH, light, oxidation and reduction stimuli, drugs can be released under single triggering of different stimuli in a controlled release process, and also can achieve controlled release through joint triggering of multiple stimuli. Therefore, the multi-stimuli responsive shell crosslinked polymeric micelle has broad application prospect in controlled release of anti-cancer drugs and other fields.

Provided herein are biodegradable copolymers and nanoplex delivery systems comprising the same and a cargo molecule, such as a nucleic acid, a polynucleotide or other biomolecule. The biodegradable copolymers may comprise a reducible polymer linearly modified with lysine, such as a linear lysine-modified N,N′-cystamine bisacrylamide. The biodegradable copolymers also may be conjugated to a sequestering moiety, such as dietheylamine. The biodegradable copolymers also may comprise one or both of a targeting moiety and one or more moieties to facilitate endosomal escape. Also provided are methods for treating a pathophysiological condition and for increasing biocompatibility of a polymeric delivery system upon delivery to a subject using the biodegradable copolymers and nanoplexes.

The invention discloses a cystamine diisocyanate monomer, cystamine diisocyanate monomer based polymers as well as a preparation method and an application of the cystamine diisocyanate monomer. The cystamine diisocyanate monomer contains a reductive breakable disulfide bond, and the chemical structural formula is shown in the specification; the cystamine diisocyanate monomer can produce linear reductive degradable polyurethane or polyuria through polycondensation with a dihydroxyl compound or a diamino compound, can also produce a reticulated reductive degradable polyurethane through polycondensation with a trihydroxyl compound and can be taken as a coupling agent to connect two polymers with different structures for preparation of a reductive sensitive block polymer. The reductive degradable polymers synthesized from cystamine diisocyanate and containing the disulfide bond can be applied to drug-delivery carriers.

The invention provides a preparation method of pH and reduction sensitive nano microgel based on polyglutamic acid and cystamine and application of the pH and reduction sensitive nano microgel based on polyglutamic acid and cystamine in the anti-tumor aspect. The nano microgel with a particle size of 212nm is synthesized by preparing a microgel model from raw materials including rolyglutamic acid and cystamine under electrostatic interaction, and adding a catalyst to carry out crosslinking amidation reaction. Because carboxylate anions in polyglutamic acid are combined with amino cations in doxorubicin to load medicines, a high medicine lading ratio of 17.8% can be achieved. The disulfide bond in cystamine which serves as a crosslinking agent ensures that nano particles are sensitive to reduction, and the disulfide bond can break in a cancer cell containing high-concentration reduced glutathione, and thus the nano microgel is targeted at tumors and has a controlled release function. The nano microgel is directly prepared in an aqueous solution without adopting any organic solvent, and thus the safety of the medicine carrier can be guaranteed.

Gellan can be purified from nucleic acid contamination by combining the contaminated gellan with DNase under conditions that allow the DNase to degrade the nucleic acid contaminant. The purified gellan is useful in gel electrophoresis. A buffer which allows cystamine to be used as a reversible cross-linker does not have to be recirculated during the course of a normal gel run.

The invention discloses a preparation method of microenvironment-sensitive drug-loading nano capsules with tumor cell biological reducibility. The preparation method comprises the following steps: (1) preparing cystamine combined hyaluronic acid; (2) preparing esterified cystamine combined hyaluronic acid; (3) preparing multifunctional hyaluronic acid (Z-HA-SH); (4) preparing amino folic acid; (5) preparing a drug-loading nano capsule precursor; and (6) preparing the microenvironment-sensitive drug-loading nano capsules with tumor cell biological reducibility. The drug-loading nano capsules have good biocompatibility, no immunogenicity and high safety and can promote bioavailability of a drug, improve anti-tumor effect and reduce toxic and side effects on normal tissues.

The invention discloses a hyaluronic acid/poly(N-epsilon-acryloyl-L-lysine) dual-network aquagel capable of biological reduction and a preparation method thereof. The preparation method comprises the following steps: modifying hyaluronic acid sequentially with cystamine and glycidyl methacrylate to obtain methylacryloylated hyaluronic acid, carrying out photochemical polymerization to obtain a hyaluronic acid aquagel; carrying out freeze-drying on the hyaluronic acid aquagel, impregnating in a mixed solution of a monomer N-epsilon-acryloyl-L-lysine, a crosslinking agent N,N'-bis-acryloyl-L-cystine and a water-soluble photoinitiator, and carrying out secondary photochemical polymerization to obtain the hyaluronic acid/poly(N-epsilon-acryloyl-L-lysine) dual-network aquagel. The dual-network aquagel has interpenetrating microstructure, has the characteristics of high mechanical strength, flexible and adjustable mechanical, swelling and degradation properties and the like, and is capable of biological reduction. The method has the advantages of favorable raw material economy, simple technique and short reaction time. The obtained gel has the advantages of stable structure, high strength and the like, and has favorable application prospects.

The invention discloses a method for preparing superoxide dismutase (SOD)-loaded gamma-poly glutamic acid hydrogel. The method comprises the following steps: adopting a 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) activation system, and forming an SOD-gamma-polyglutamic acid (PGA) immobilized product by using lysine residues and poly glutamic acid side chain carboxyl of SOD; crosslinking the SOD-gamma-PGA obtained by the reaction by using a diamine crosslinking agent cysteamine hydrochloride, so as to form an SOD-gamma-PGA gel system. The gel system can be applied to wound dressing or mask, and can play the antioxidant damage action, and the skin wound is quickly repaired.

The invention relates to a preparation method Fe3O4 nanoparticles with a cluster structure. The preparation method comprises steps as follows: preparation of extra small Fe3O4 nanoparticles, preparation of an activated extra small Fe3O4 nanoparticle solution, and preparation of the Fe3O4 nanoparticles with the cluster structure. The preparation method is simple, the prepared Fe3O4/Cystamine nanoparticles have good stability and biocompatibility, are sensitive to reducing conditions, can realize T1-T2 dual-mode MR imaging effect of a tumor location in an animal body, can be effectively taken asan MR imaging contrast medium and have industrialized and commercialized application prospect.

The invention relates to a hyaluronic acid-cystamine-polylactic acid-glycollic acid graft polymer and a preparation method thereof. The structural formula of the hyaluronic acid-cystamine-polylactic acid-glycollic acid graft polymer is disclosed as Formula (1), wherein n is a whole number ranging from 16 to 30, the Y:X ratio is (1-3):1, Y is a whole number ranging from 153 to 549, and X is a whole number ranging from 73 to 385; and the hyaluronic acid and the polylactic acid-glycollic acid are connected through a micromolecule (2) cystamine. The hyaluronic acid-cystamine-polylactic acid-glycollic acid graft polymer has the advantages of favorable biocompatibility effect and low toxicity, has the tumor tissue targeting action when being used as a drug carrier material, can be decomposed in a redox environment in the tumors, and has the function of controlled release of drugs.

The invention relates to a targeted pH-GSH dual-response multifunctional nano-vesicle drug loading system. By using cystamine functionalized column [5] aromatic hydrocarbon with pH-GSH dual responsiveness as a host molecule and using a pyridinium modified galactose derivative as a guest molecule, glycosyl-functionalized column [5] aromatic hydrocarbon amphiphilic molecule is prepared through the host-guest interaction; nano-vesicle is formed in a solution through hydrophilic and hydrophobic effect; and an anti-cancer drug is encapsulated in the vesicle cavity so as to construct the targeted pH-GSH dual-response multifunctional nano-vesicle drug loading system. As the surface of vesicle contains galactosyl, biocompatibility of the system can be remarkably raised. Meanwhile, galactosyl can interact with specific galactose binding protein overexpressed on the surface of hepatoma carcinoma cell to realize targeted selective access to cancer cell so as to rapidly release an anti-cancer drugin the cancer cell and raise lethality of cancer cell.

The invention provides a magnetic material for efficiently detecting a circulating tumor cell and a preparation method of the magnetic material. The preparation method comprises the steps of: (1) allowing hyaluronic acid, 1-(3-dimethylamino propyl)-3-ethyl-carbodiimide hydrochloride, 1-hydroxybenzotriazole, cysteamine hydrochloride and dithiothreitol to react to prepare HA-SH, (2) grafting rhodamine onto HA-SH to prepare RhB-HA-SH, (3) allowing an Fe3O4 nanoparticle, RhB-HA-SH and H2O2 to react to prepare superparamagnetic fluorescent HA-SH, and (4) allowing superparamagnetic fluorescent HA-SH, 1-(3-dimethylamino propyl)-3-ethyl-carbodiimide hydrochloride, 1-hydroxybenzotriazole, PEG-FA and anti-EpCAM (epithelial cell adhesion molecule) to perform antibody reaction to prepare the magneticmaterial. The magnetic material is high in saturation magnetization, and good in magnetic response and biocompatibility, can achieve specific binding with the circulating tumor cell and has certain universality.

The invention discloses a dentritic heparin nano-material and a modified biological type artificial blood vessel. The dentritic heparin nano-material provided by the invention has a terminal branch unit shown in formula I, and is obtained by a reaction between polyamidoaminedendrimers using hydrazide group as a terminal group and heparin, wherein the inner core of the polyamidoaminedendrimers is cystamine, and the dentritic frame of the polyamidoamine dendrimers is hydrazide modified polyamidoamine including -0.5, 0.5, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5 and 7.5; and the connection between the heparin and polyamidoamine is a glycosidic bond formed a reaction between the hydrazide on the surface of the polyamidoamine and the heparin reducing terminal. The disulfide bond in the dentritic heparin nano-material is cut through a reducing agent to obtain a sulfydryl site which can react with an intravascular stent material; and the surface in a blood vessel can be activated through a coupling agent of a two-way functional group, and the heparin with a branch structure can be fixed on the inner surface of the blood vessel material through chemical bond covalence, so that a composite artificial blood vessel with an anticoagulation effect can be obtained.

The invention discloses a preparation method of modified carboxymethyl chitosan nano gel, belonging to the technical field of carriers and sustained-release material. The preparation method comprises the following steps: firstly preparing methylacryloyl carboxymethyl chitosan; and performing free radical polymerization in the presence of N'-N-bis(acrylyl) cystamine serving as a cross-linking agent to prepare the modified carboxymethyl chitosan nano gel. Through determining the particle size and zeta potential of nano particles under the condition of different pH values, the modified carboxymethyl chitosan nano gel is proved to have a pH sensitivity. A protein adsorption test shows that the nano gel is capable of preventing protein adsorption. The prepared nano gel is used for successfully carrying anticancer drug doxorubicin hydrochloride; in-vitro release tests in which PBS solutions different in pH and glutathione concentration are used as media prove that the drug-carried nano particles have relatively good pH and reduction sensitivity.

The invention discloses a preparation method of an oxidoreduction responsiveness tumor-targeted cis-platinum nanometer drug delivery system, and application thereof, relates to the building and the preparing of a high-load cis-platinum macromolecule pro-drug and a hyaluronic acid-coated high-load cis-platinum nanometer drug delivery system, and can be applied to active targeting treatment of tumors. Polyethyleneimine is adopted as a framework, and cystamine containing a disulfide bond with oxidoreduction responsiveness is selected to be reacted with butanedioic anhydride so as to be complexedwith cis-platinum, so that a cis-platinum complex is obtained. The obtained cis-platinum complex and the polyethyleneimine are covalently bonded to obtain the high-load cis-platinum macromolecule pro-drug, and a hyaluronic acid targeted group is coated on an outer layer, so that the oxidoreduction responsiveness tumor-targeted cis-platinum nanometer drug delivery system with a tumor active targeting function is obtained. Compared with traditional chemotherapy drug cis-platinum, the oxidoreduction responsiveness tumor-targeted cis-platinum nanometer drug delivery system provided by the invention can realize tumor active targeting drug delivery and oxidoreduction responsiveness drug release, plays a role in anti-tumor treatment, is capable of effectively reducing the toxic and side effects caused by the cis-platinum on other visceral organs of a body, and has a favorable clinic application prospect.

The invention relates to the technical field of biomedical materials, in particular to a reductively degradable polyzwitterionic nano-micelle and a preparation method thereof. The preparation method comprises the following steps: producing a copolycondensation reaction of taurine, N,N-bis(acryloyl)cystamine and dodecylamine through a Michael addition mechanism, synthesizing to obtain poly(taurine-co-N,N-bis(acryloyl)cystamine-co-dodecylamine)terpolymer, and forming the nano-micelle through self-assembly in an aqueous solution. As a chain segment of the terpolymer contains structural units such as amino groups, disulfide bonds, zwitter-ions and the like, the nano-micelle has sensitive pH (potential of hydrogen) and reduction response properties, and the zwitter-ions endow the nano-micelle with excellent anti-protein non-specific adsorption performance; the nano-micelle does not have cell toxicity, is completely degradable in a human body and serves as an anti-cancer drug carrier, thereby having a relatively high application prospect.

The invention provides a pharmaceutical composition and a preparation method thereof. The pharmaceutical composition comprises a carrier and an active ingredient loaded on the carrier, wherein the carrier is a nanoparticle of a hyaluronic acid-cystamine-polylactic acid-glycolic acid grafted polymer as shown in a formula (I) as shown in the specification; in the formula (I), n is an integer ranging from 16 to 30, the ratio of Y to X ranges from (1-3): 1, Y is an integer ranging from 153 to 549 and X is an integer ranging from 73-385. The pharmaceutical composition is capable of realizing directional delivery so that the medicine can be released quickly in cells and the effect of the medicine can be improved.

The invention relates to the technical field of biomedical materials, in particular to a preparation method of injection xanthan gum nano microgel. The method comprises the steps of preparing cystamine tetrahydrazide, allowing cystamine tetrahydrazide and xanthan gum to directly perform an amidation reaction in an aqueous solution to form cross-linking xanthan gum, and dialyzing in the aqueous solution to form the polymer nano microgel. The xanthan gum as anionic polysaccharide contains amino, carboxyl and a disulfide bond after a cross linking reaction with cystamine tetrahydrazide, so that nano particles are endowed with high pH (potential of hydrogen) and reduction sensitivity and have excellent anti-protein non-specificity adsorbability under normal physiological conditions; a nano particle structure contains free hydrazide groups and can load an anticancer drug, adriamycin, via a covalent bond to form an acylhydrazone bond with pH sensitivity; and the control of drug release is facilitated. The nano microgel has good biocompatibility, can be completely degraded in vivo and is expected to serve as an anticancer drug carrier and controlled release.