176 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 relates to a reducible and degradable nano medicine-carrying micelle and a preparation method thereof, belonging to the fields of biomedical technology and nano medical technology. The reducible and degradable nano medicine-carrying micelle is characterized by having the following structural general formula: MPEG-CA-PCL, wherein the CA is poly-cystamine containing disulfide bonds, the MPEG is methoxy polyethylene glycol the molecular weight of which is 475-5000DA, and the PCL is polycaprolactone. The preparation method of the reducible and degradable nano medicine-carrying micelle comprises the following steps: (1) carrying out Michael addition to N,N'-bis (acrylic) cystamine and ethanolamine to obtain hydroxy poly-cystamine containing disulfide bonds, and then, carrying out ring opening reaction on caprolactone by utilizing a hydroxy group to obtain a CA-PCL polymer; and (2) mixing the CA-PCL polymer obtained in the step (1) and carboxyl-terminated MPEG, and adding paclitaxel (PTX) to prepare the nano medicine-carrying micelle through a dialysis method. The method is efficient and simple.

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 provides enzyme-catalyzed disulfide bond-crosslinked natural polymer hydrogel and a preparation method thereof. The hydrogel comprises a three-dimensional net structure composed of crosslink bonds of cystamine or N,N-diacetyl-L-cystine; under the conditions that horseradish peroxidase is used as a catalyst and a phenol compound is used as an enzyme substrate, sulfydryl-grafted natural polymers are rapidly oxidized to form disulfide bonds, so that the hydrogel is obtained. According to the invention, raw materials are safe in source and environment-friendly, the product has excellent biocompatibility; reaction conditions are mild, and the operation is simple; the system is not required to be additionally added with hydrogen peroxide, and physiological activity of a loaded drug or cells is completely guaranteed.

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.

The invention relates to a preparation method of water stability gamma-polyglutamic acid nanometer fibers. The preparation method comprises the steps of: (1) preparing trifluoroacetic acid water solution of which the mass percentage concentration is 5%-10%, dissolving gamma-polyglutamic acid in the trifluoroacetic acid solution and stirring the solution for 6-8 hours to obtain gamma-polyglutamic acid solution; (2) spinning the gamma-polyglutamic acid solution via static spinning to obtain gamma-polyglutamic acid nanometer fibers; and (3) dissolving the gamma-polyglutamic acid nanometer fibersand EDC (ethylene dichloride) in methanol to have a reaction at room temperature for 3-5 hours, adding cystamine dihydrochlorid to have a reaction for 48-72 hours after the reaction is ended, rinsing, freezing and drying the products after the reaction of cystamine dihydrochlorid is ended, thus obtaining gamma-polyglutamic acid nanometer fibers with good water stability. The preparation method ofthe water stability gamma-polyglutamic acid nanometer fibers is simple and convenient in operation and has moderate technique conditions; the raw materials are easy to obtain, and the prepared gamma-polyglutamic acid nanometer fibers have good biocompatibility so the gamma-polyglutamic acid nanometer fibers have latent application merits in the field of the histological engineering bracket.

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 preparation method and a use of degradable polymer nano-microcapsules. The preparation method comprises the following steps of carrying out backflow deposition on an acrylic acid monomer to produce uncross-linked polymer nano-microspheres, carrying out backflow deposition to coat a disulfide bond cross-linked polymer shell layer on the surface of the uncross-linked polymer nano-microsphere by disulfide bond-containing N,N'-bis(acryloyl)cystamine as a cross-linking agent, transferring the prepared core-shell composite microspheres into ethanol or water, and carrying out uncross-linked polymer core etching to obtain the degradable polymer nano-microcapsules having monodispersity. The preparation method can be carried out fast, has simple aftertreatment processes, is free of an etching process adopting strong acid or strong alkali and is safe and efficient. After freeze-drying treatment, the degradable polymer nano-microcapsule can carry doxorubicin as a cancer-resistant drug and the cavity of the degradable polymer nano-microcapsule is further filled with perfluorohexane having ultrasonic response so that the degradable polymer nano-microcapsule is effectively used as an ultrasonic contrast agent and a drug carrier. The ultrasonic contrast agent can be fast decomposed to form very low molecular-weight linear molecules (Mn<5000) in the presence of glutathione or dithiothreitol as a reducing agent.

The invention discloses self-healing conductive hydrogel and a preparation method and application thereof. The hydrogel is prepared from, by weight, 76-107 parts of hydrophobic modified polyacrylamideserving as a hydrogel matrix, 0.2-1 part of small molecular surface modified silver nanowires and 4-14 parts of glucan through one-step in-situ synthesis. The small molecular surface modified silvernanowire is a small molecular organic matter N, N-bisacryloyl cystamine surface modified silver nanowire. The two ends of the self-healing conductive hydrogel are connected with wires and packaged toobtain the self-healing conductive hydrogel sensor. According to the preparation method, the conductive, high-strength and self-healing hydrogel can be prepared simply and efficiently, self-healing can be realized after fracture, and the conductivity and the sensibility can be recovered.

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.

Improved poly(amido ethylenimine) copolymers for gene delivery are disclosed. One illustrative embodiment includes polyethylene glycol (PEG) covalently bonded to a branched poly(triethyenetetramine / cystamine bisacrylamide) copolymer (poly(TETA / CBA)). The polyethylene glycol can be linear or branched. Another illustrative embodiment includes an RGD peptide covalently bonded to the poly(TETA / CBA)-PEG conjugate. Still another illustrative embodiment includes a method of using these compositions for transfecting a cell with a nucleic acid.

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 provides a fully-dissociable type polyethylene glycol-poly(L-glutamate-gamma-benzyl ester)-polyethyleneimine copolymer as well as a synthesizing method and application thereof. The method comprises the following steps: performing cystamine modification on terminated methoxy polyethylene glycol; initiating a ring-opening polymerization of gamma-benzyl ester-L-glutamate-N-carboxyanhydride by utilizing the terminated amine of the terminated methoxy polyethylene glycol; connecting the product in the ring-opening polymerization and polyethyleneimine by utilizing 2,2'-dithio-diethyl isocyanate by virtue of an addition reaction to obtain the target product. According to the method, the synthesized copolymer is amphipathic, can be self-assembled to form nano-particles; chemotherapeutic medicines and genetic medicines can be simultaneously loaded to the copolymer when the copolymer is used as a medical vector; the copolymer can be completely dissociated and disintegrated by responding glutathione and other reductive substances, so that the vector can escape from endosome to cytoplasm, medicines can be quickly released, and the treatment effect can be improved. The method can be used for controlling the molecular weight and length of each fragment in the segmented copolymer, is mild in reaction condition, and is suitable for more medicine types.

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 provides a photonic crystal hydrogel film, which comprises Fe3O4 nano particles and polyacrylamide-methylene bisacrylamide-N,N'-bis(acroloyl)cystamine hydrogel. The invention further provides a preparation method. Fe3O4 nano particles, acrylamide, methylene bisacrylamide, N,N'-bis(acroloyl)cystamine, and a photoinitiator are evenly dispersed into an organic solvent, then a magnetic field is loaded, and finally the solution is irradiated by UV rays to obtain the photonic crystal hydrogel film, which can be applied to naked eye detection or a bio-molecular sensor. By loading a magnetic field, Fe3O4 nano particles are arranged in a one-dimensional chain; then the film is synthesized through UV irradiation; the film has a single color, is pure, can respond to reductive glutathione, has high specificity and sensitivity on reductive glutathione, can be applied to naked eye detection, and solves the problems that the detection of reductive glutathione is very expensive and the operation is tedious; and a novel method is provided for the detection of reductive glutathione in a water solution.

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 discloses a synthesis method and an application of an mPEG-poly(L-glutamic acid-gamma-hydrazide)-PDMAPMA triblock copolymer. According to the invention, end methoxy polyethylene glycol is subjected to cystamine modification; a gamma-benzyl ester-L-glutamic acid-N-carboxyanhydride ring-opening polymerization reaction is initiated; with a carbodiimide method, a small-molecular RAFT polymerization chain-transfer agent is bonded to an obtained diblock copolymer; RAFT polymerization is carried out with N-(3-dimethylaminopropyl)methacrylamide as a monomer; and benzyl group is removed through hydrazinolysis, such that polyethylene glycol-poly(L-glutamic acid-gamma-hydrazide)-poly(N-(3-dimethylaminopropyl)methacrylamide) triblock copolymer is obtained. With the synthesis method provided by the invention, molecular weights and chain lengths of all blocks of polymers can be flexibly controlled. Reaction conditions are mild, and raw materials are easy to obtain. The copolymer has a characteristic that the copolymer is amphiphilic when loading adriamycin, such that the block copolymer can be self-assembled into nano-particles. The copolymer can load chemotherapeutic drugs and genetic drugs at a same time. Drug potency is high, and toxic and side effects are greatly reduced.

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.

The invention relates to the use of cystamine, cysteamine, or a salt thereof, or of calcineurin inhibitors for treating a MeCP2-associated disorder such as Rett syndrome.