87results about How to "Good pH sensitivity" patented technology

Disclosed is a block copolymer formed by coupling the following components with each other: (a) a copolymer (A) of a polyethylene glycol (PEG) type compound with a biodegradable polymer; and (b) at least one oligomer (B) selected from the group consisting of poly(β-amino ester) and poly(amido amine). A method for preparing the same block copolymer, and a polymeric hydrogel type drug composition comprising the temperature and pH-sensitive block copolymer and a physiologically active substance that can be encapsulated with the block copolymer are also disclosed. The multiblock copolymer is obtained by copolymerization of a pH-sensitive poly(β-amino ester) and / or poly(amido amine) type oligomer, a hydrophilic and temperature-sensitive polyethylene glycol type compound and a hydrophobic and biodegradable polymer. Therefore, the block copolymer can form a polymeric hydrogel structure due to its amphiphilicity resulting from the combination of a hydrophilic group and a hydrophobic group in the copolymer and ionization characteristics depending on pH variations, and thus can be used as a drug carrier for target-directed drug delivery depending on pH variations in the body.

The invention discloses a preparing method of pH value sensitive dialdehyde starch crosslinking carboxymethyl chitosan aquagel, which comprises the following steps: blending carboxymethyl chitosan solution with density at 1-4% and dialdehyde starch solution with density at 1-6% according to the weight rate at 1:0.5-5.0; stirring evenly under 30-60 Deg C; defoaming in the vacuum; stewing at indoor temperature for 6-36h to form gel; washing through deionized water; drying in the vacuum to obtain constant weight material as the product.

The invention provides a bispyrene-based pH (Potential of Hydrogen)-response self-assembly polypeptide nano material, and a preparation method and application thereof. The bispyrene-based pH-response self-assembly polypeptide nano material has a structure as shown in formulas I to IV. The bispyrene-based pH-response self-assembly polypeptide nano material has pH response, can be self-assembled into nano fiber under the environment that the pH is greater than or equal to 1.0 and smaller than 8.0 and can be assembled into nanospheres under the environment that the pH is greater than or equal to 8.0, and a hydrophobic micromolecular imaging agent and medicine can be recruited, so that the utilization rate of the micromolecular imaging agent and treatment medicine can be greatly increased; the bispyrene-based pH-response self-assembly polypeptide nano material can be converted into fiber in positions of ill tissues or cells in situ, is capable of greatly prolonging the retention time, can be used for biological imaging and treating, is capable of providing a reliable diagnosis and targeted therapy method for disease treatment, and has a wide application prospect.

The invention discloses a modification method for functionalizing the surface of a material. The modification method comprises the following steps of: (a) preparing a dopamine functional monomer; (b) in a reaction device, enabling the material to react with an alkaline solution containing the dopamine functional monomer; (c) obtaining a material of which the surface is connected with a carbon-carbon double-bond after the reaction in the step (b) is finished; (d) in the reaction device, performing free radical type graft copolymerization reaction on the material of which the surface is connected with the carbon-carbon double-bond, obtained in the step (c), and a monomer solution containing an initiating agent; and (e) obtaining a modified material of which the surface is functionalized after the graft copolymerization reaction in the step (d) is finished to finish the modification for functionalizing the surface of the material. The modification method disclosed by the invention is simple and convenient to operate and strong in universality.

The invention provides a polyurethane block copolymer, which comprises a block A shown as a formula (I) and or a formula (III) and a block B shown as a formula (II). Since the polyurethane block copolymer simultaneously contains a tertiary amine group and a 1, 2-dithioheterocyclic ring, the polyurethane block copolymer has good pH (potential of hydrogen) sensitivity, good reduction sensitivity and unique amphipathic characteristic, the pH sensitive interval is between 5.5 and 7.0, and responses can be quickly made to both physiologically related pH changes and oxidation-reduction environment changes. The invention additionally provides a preparation method of the polyurethane block copolymer, wherein the preparation method of the polyurethane block copolymer is simple, feasible and easy to control. The invention additionally provides a preparation method of polyurethane block copolymer nano hydrogel. Since the molecular chain of the polyurethane block copolymer contains the 1, 2-dithioheterocyclic ring, inter molecular chain linkage can happen to obtain nano hydrogel. The nano hydrogel has the advantages that the self-assembling form can be changed with pH and oxidation-reduction environment, the stability is high and the medical application prospect is good.

The invention discloses a method for synthesizing chitosan cross-linked polymaleic anhydride super absorbent resin. The method is as follows: biodegradable N-maleoyl chitosan is used as a cross-linking agent, maleic anhydride (MA) and acrylic acid (AA) are used as raw materials, and ammonium persulfate and sodium bisulfite are used as initiating agents; an aqueous solution free radical polymerization reaction is performed to synthesize the biodegradable super absorbent resin; an orthogonal experiment method is used to optimize the synthesis conditions to obtain optimum synthesis conditions. The chitosan cross-linked polymaleic anhydride super absorbent resin prepared using the method provided by the invention is good in water absorption, swelling dynamic performance, water retention capability under natural conditions, repeated water absorption, pH sensitivity and biodegradability.

The invention belongs to the field of medicinal preparations, and relates to a tumor-targeting pH-sensitive polymeric micelle composition, and especially relates to a pH-sensitive polymeric micelle composition encapsulating a poorly-soluble anti-tumor medicine. The tumor-targeting pH-sensitive polymeric micelle composition is constructed by employing biologically-compatible pH-sensitive amphiphilic block polymer and an amphiphilic polymer connected with a targeting ligand or an antibody in a certain ratio, and the composition encapsulates a poorly-soluble anti-tumor medicine. Experiments prove that the polymeric micelle composition has pH-dependent release characteristic, is accumulated in tumor tissue in a high concentration, has specifically targeting inhibiting effect on growth of tumor cells, and provides a novel carrier and preparation strategy for poorly-soluble anti-tumor medicines.

The invention provides a bi-locus ratio type pH probe for high-sensitivity detection of changes of the pH value inside a cell. The synthesis steps of the probe are designed. The invention further provides application of the fluorescent probe in distinguishing live and dead cells. The probe synthesis method is simple and capable of achieving high-sensitivity ratio type detection of pH inside the cell, and has the great application prospect.

The invention belongs to the field of medicinal preparations, relates to a pH-sensitive polymeric micelle composition resisting tumor drug resistance, and especially relates to a pH-sensitive polymeric micelle composition resisting tumor drug resistance and encapsulating a poorly-soluble anti-tumor medicine. The pH-sensitive polymeric micelle composition resisting tumor drug resistance is constructed by employing two kinds of biologically-compactable pH-sensitive amphiphilic block polymer and an amphiphilic polymer D-alpha-tocopherol polyethyleneglycol succinate (TPGS) as a P-gp inhibitor in a certain ratio, and encapsulates a poorly-soluble anti-tumor medicine. Experiments prove that the polymeric micelle composition has pH-dependent release characteristic, is accumulated in tumor tissue in a high concentration, has specifically targeting inhibiting effect on growth of tumor cells generating drug resistance because of over expression of P-glycoprotein, and provides a novel carrier and preparation strategy for poorly-soluble anti-tumor medicines and reversing of drug resistance of tumor cells.

The invention discloses a bio-safety carbon quantum dot-loaded adriamycin complex. A preparation method of the bio-safety carbon quantum dot-loaded adriamycin complex comprises the following steps: (1) mixing milk and deionized water according to the volume ratio of (5-6):(4-5), then putting at a temperature of 160-200 DEG C and heating for 2-4 hours; (2) cooling to a room temperature, centrifuging for 30-45 minutes under 10000-12000 r / min and taking supernatant liquid; (3) filtering with a filter membrane to obtain a carbon quantum dot solution; (4) preparing a carbon quantum dot aqueous solution; (5) preparing an adriamycin aqueous solution; (6) mixing the carbon quantum dot aqueous solution, the adriamycin aqueous solution and a PBS solution and preparing a mixed solution with pH being equal to 7.4; (7) performing light-shading reaction and dialysis to prepare. The preparation method is simple, the adriamycin load rate is high, the prepared complex is high in bio-safety, the killing efficiency of tumor cells is significantly improved, the killing efficiency of normal cells is significantly reduced, and the bio-safety carbon quantum dot-loaded adriamycin complex can be used for tumor disease treatment.

The invention relates to a method for preparing a fertility-increasing and detoxifying type acidic soil conditioner, and belongs to the technical field of acidic soil treatment. The method comprises the following steps: mildewing biomass wastes pig manure and mushroom bran which are used as raw materials, charring the mildewed raw materials to obtain high-porosity biomass charcoal, oxidizing the biomass charcoal with concentrated sulfuric acid and potassium permanganate, performing blending fermentation on the oxidized biomass charcoal and grape skins and ginger skins containing amino acids and flavonoids, performing microbial degradation to degrade the amino acids and flavonoids in order to produce a large number of free carboxyl and carbonyl groups, introducing the carboxyl and carbonylgroups to the surface of the charcoal under the self-crosslinking action of microorganisms to obtain a fermentation product, performing mixing impregnation on the fermentation product and a sodium alginate solution, concentrating the obtained solution, freeze-drying the concentrated solution, and crushing the freeze-dried concentrated solution to obtain the fertility-increasing and detoxifying type acidic soil conditioner. The fertility-increasing and detoxifying type acidic soil conditioner has the advantages of increase of the pH value of the soil, alleviation of aluminum toxicity, improvement of the fertility of the soil, and broad application prospect.

The invention discloses a method for preparing environment-sensitive cyclodextrin derivative hydrogel. The method comprises the following steps: reacting cyclodextrin, methacrylic acid and 1,2-dicyclohexyl carbonyl diimine to prepare methacrylate-cyclodextrin; and reacting the methacrylate-cyclodextrin, methacrylic acid, a cross-linking agent N,N'-methylene biisopropylacrylamide and acrylamide in the presence of an initiator ammonium persulfate solution, thereby obtaining the gel. The gel prepared by the invention has pH sensitivity and temperature sensitivity, is high in swelling ratio under alkaline conditions and low in swelling ratio under acidic conditions, is a very ideal carrier used for controlling and releasing drugs into the intestinal tract and contributes to realizing temperature-sensitive drug release.

The invention discloses a polyurethane segmented copolymer simultaneously containing disulfide bonds and tertiary amine groups. Active sites can be easily introduced at a main chain and a chain end for molecular modification, the structure and function diversification is realized, and in addition, the multiplex regulation control is easily carried out on the polymer structure. The polyurethane segmented copolymer has good pH sensibility, reduction sensibility and unique amphipathic characteristics, the pH sensitive range is between 5.5 and 7.0, the polyurethane segmented copolymer can simultaneously make fast response to relative physiological pH and oxidation reduction environment change, in addition, materials can form a stable nanometer micellar structure in water, the self-assembly form of the nanometer micellar structure can be changed along with the pH and oxidation reduction environment change, and good medical application prospects are realized. Correspondingly, the invention also provides a preparation method of the polyurethane segmented copolymer, the method is simple and is easy to implement, the control is easy, and the polyurethane segmented copolymer simultaneously containing disulfide bonds and tertiary amine groups is prepared.

The present invention is the preparation process of fast responding pH sensitive hydrogel, and belongs to the field of polymer material preparing technology. The preparation process of the hydrogel includes the following steps: dissolving sulfadiazine in alkali aqua and acetone solution, dripping acrylyl chloride to react, filtering the product, washing to eliminate unreacted monomer and impurity and drying to obtain sulfadiazine monomer; mixing N-vinylpyrrolidone, sulfadiazine monomer, 1N, N-methylene diacrylamide, azodiisobutyronitrile and dimethyl sulfoxide to form mixed solution and react in water bath at 30-100 deg.c for 2-24 hr to obtain hydrogel; soaking and washing with deionized water to eliminating unreacted monomer, cross-linking agent and solvent impurity, and drying to obtain the pH sensitive hydrogel. The prepared pH sensitive hydrogel is especially sensitive in pH 6.8-7.2, and is expected to prepare medicine release controlling supplementary material.

The invention relates to a modified succinyl chitosan hydrogel as well as a preparation method and the application thereof, and mainly solves problems that an ordinary hydrogel material is insufficient in antibacterial and other functional properties and not safe enough in crosslinking system. According to the modified succinyl chitosan hydrogel provided by the invention, non-toxic and biocompatible 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are used as cross-linking agents; and succinyl chitosan and 2.0-generation polyamide-amine dendrimer are subjected to cross-linking reaction to obtain hydrogel with a novel crosslinked net structure. The hydrogel not only has an outstanding swelling property and pH sensitivity, but also has an excellent antibacterial property, and has a good application potential in the field of biomedical materials.

The invention provides a poly (L-glutamic acid) / polyacrylic acid hydrogel and preparation method thereof. The hydrogel contains poly (L-glutamic acid-g-hydroxy ethyl acrylate), polyacrylic acid and water. The preparation method includes the following steps: pH value of acrylic acid buffer solution is regulated to be 8-9, so as to obtain a first reaction solution; poly (L-glutamic acid-g-hydroxy ethyl acrylate) buffer solution is added into the first reaction solution, so as to obtain a second reaction solution; initiator is added into the second reaction solution to obtain a third reaction solution, the third reaction solution is subject to heating or irradiation to obtain reaction product; and the reaction product is placed into deionized water to be soaked, thus obtaining the poly (L-glutamic acid) / polyacrylic acid hydrogel. The poly (L-glutamic acid) / polyacrylic acid hydrogel prepared by the preparation method has biodegradability and high pH sensibility and is especially suitable for being used as oral drug release carrier.

The invention discloses a novel pH sensitive phospholipid molecule taking pentaerythritol as a skeleton, and a preparation method as well as application of the phospholipid molecule, and particularly relates to the novel pH sensitive phospholipid molecule shown as a formula (I). The phospholipid molecule can form a liposome in an aqueous solvent; acetal bond is sensitive to an acid environment, so that the liposome can be quickly dissociated under an acidic condition, and thus an aim of quickly releasing load is achieved. The phospholipid molecule has the characteristics of ultraviolet absorption, easy detection and no cytotoxicity to tumor cell, and has great potential in becoming an acid sensitive medicinal material; the formula (I) is shown in the description.

The invention discloses a corrosion inhibition material and application thereof. The invention relates to a corrosion inhibition material. The corrosion inhibition material comprises halloysite nanotubes, wherein lignosulfonate is loaded in the halloysite nanotubes; and the surface of the halloysite nanotube contains a polydiene dimethyl ammonium chloride and sodium polystyrenesulfonate coating layer. The halloysite nanotube coating comprises the corrosion inhibition material and a resin coating. The prepared halloysite nanotube coating has remarkable sensitivity to pH environment change, electrochemical impedance spectroscopy and water contact angle tests show that the prepared halloysite nanotube coating has excellent corrosion resistance, and water contact angle test results show that the prepared halloysite nanotube coating has good hydrophobicity; and the corrosion inhibition material is reasonable in step design, the preparation process is controllable, and industrial mass production can be realized.

The invention relates to pretreatment before metal coating, discloses a pottery agent, a preparation method thereof and a pottery process, and solves the problem of fast easy re-rusting time caused byweak corrosion resistance of pottery films obtained by a traditional pottery process. The pottery agent comprises the following components in parts by mass: 5-10 parts of sodium hexafluorozirconate,3-5 parts of potassium fluotitanate, 5-10 parts of silane coupling agent, 5-8 parts of tartaric acid, 62-77 parts of de-ionized water, and 10-15 parts of nanometer silicon powder. Water and an adjusting agent are added in the pottery agent for dilution to prepare pottery liquid; metal workpieces are conveyed by a conveying lifting frame to move through a phosphorus-free cleaning chamber, a first ultrasonic cleaning tank and a first water washing tank in sequence for cleaning and degreasing, are derusted and cleaned by an acid washing tank, a second water washing tank and a second ultrasonic cleaning tank, and enter a first pottery pool with the pottery liquid for pottery to form pottery films on the surfaces; and the obtained pottery films improve the corrosion resistance, and achieve excellent rust resistance.

The invention discloses an SPIO labeled pH sensitive drug-carrying liposome which is prepared from the following components in parts by mass: 1-10 parts of bulk drugs, 1-50 parts of phosphatidyl ethanolamine, 1-30 parts of cholesterol, 1-30 parts of linoleic acid, 0-10 parts of carboxymethyl chitosan, and 0-10 parts of superparamagnetic iron oxide nanoparticles. The invention further discloses a preparation method of the SPIO labeled pH sensitive drug-carrying liposome. The preparation method comprises the following steps: S1, placing phosphatidyl ethanolamine, cholesterol and linoleic acid ina flask, adding chloroform for dissolving, adding a water soluble drug solution for ultrasonic treatment to form a W / O emulsion; S2, evaporating to a gel state under the pressure reduction condition;adding a buffering solution, and continuously evaporating to form an aqueous suspension; S3, adding the superparamagnetic iron oxide nanoparticles and performing freeze thawing on a liposome suspension for three times; and centrifugally removing the superparamagnetic iron oxide nanoparticles and the water soluble drug not in the aqueous suspension; and S4, adding a carboxymethyl chitosan solutionfor hydration.

The invention relates to folic acid modifying chitosan nano particles as well as preparation and application thereof. The preparation method comprises the following steps: adding folic acid FA, EDC and NHS into a solvent, stirring, and obtaining a mixed solution; and adding the mixed solution into a prepared aqueous solution of chitosan temperature-sensitive segmented copolymer CS-g-PNIPAM, stirring, dialyzing, and freeze drying, thus obtaining the folic acid modifying chitosan nano particles. By adopting the RAFT method, the reaction is stable, no implosion occurs, and a reaction product is low in molecular weight dispersion width.

A preparation method of a battery composite material includes steps of providing phosphoric acid, manganese carbonate, water and a first reactant; processing a reaction of the phosphoric acid, the manganese carbonate and the water to produce a first product; calcining the first product to produce a precursor, which is written by Mn2P2O7; processing a reaction of the precursor and at least the first reactant to get a reaction mixture, and then calcining the reaction mixture to produce the battery composite material. As a result, the present invention achieves the advantages of reducing the times of the reduction-oxidation reaction, so that the stability of the processes is enhanced, and the difficulty of the processes is reduced.

A synthetic polymer material for coating feed additive and its preparation are disclosed. The process is carried out by: taking styrene, diacetyl-pyridine or acrylic amide or methyl-acrylic dimethylamine carbethoxy monomer as raw materials, taking K2S208 as evocating agent and synthesizing to obtain ternary irregular co-polymer. It's stable, has better pH sensitivity and damp resistance. It can avoid feed additive or medicine from being decomposed early.

The invention discloses a method for preparing 5-fluorouracil delivery microspheres, wherein the method includes the steps of modification of butanedioic anhydride, preparation of sodium alginate microspheres, preparation of sodium alginate-chitosan microspheres, and preparation of sodium alginate-chitosan-carrageenan microspheres. The beneficial effects comprise that the surface of the sodium alginate microspheres is coated with two polysaccharide layers, an LBL structure is formed, surface voids of the prepared core-shell type multilayer microspheres are reduced, delivery active ingredientscan reach colons through an acidic gastric juice, and a certain effect of targeted therapy is achieved; the sodium alginate-chitosan-carrageenan microsphere system shows extremely high sensitivity ina colonic weakly alkaline environment with the pH of about 7.4, has the swelling ratio in 30 minutes reaching 20 or more and has good targeting swelling selectivity at colon positions; with the selectivity, the sodium alginate-chitosan-carrageenan microspheres are expected as a special preparation colon targeted drug delivery carrier and have high market prospect.

The invention discloses a pH sensitive medical polyurethane urea material and a preparation method thereof. The preparation method comprises the following steps: mixing a terminal dihydroxypyridine compound and a double-end hydroxyl polyethylene glycol to obtain polyurethane urea, and dissolving by adding N,N-dimethylformamide, carrying out chain extension in the presence of urea-containing diisocyanate, and purifying to obtain pH-sensitive polyurethane urea, wherein diisocyanate is L-lysine diisocyanate-1,4-butylenediamine-L-lysine diisocyanate. The pyridine group on a side chain of polyurethane urea is Lewis base, which is able to decompose hydrogen bonds in a polyurethane urea network under acidic conditions, resulting in discontinuous volume expansion of material. According to the invention, H<+> is removed under neutral or alkaline conditions, and N on a pyridine ring and NH on carbamate or ureido form a hydrogen bond, approximating a network structure, so that the polyurethane urea molecular chain shrinks and the swelling degree decreases remarkably. Therefore, by controlling the change of the pH of a medium, the degree of swelling of polyurethane urea can be effectively controlled.

The invention discloses a preparation method of a core-shell type cationic microgel-nano noble metal composite material, which includes preparing a pH responsive core-shell type cationic microgel by use of hydrophilic differences of two kinds of monomers through a one-step emulsion polymerization method, performing complexing of a noble metal precursor into the network structure of the cationic microgel through electrostatic interaction by using the cationic microgel as a reducing agent, and preparing the core-shell type cationic microgel-nano noble metal composite material with good pH responsibility and stability by using the confined effect of the microgel and the reducibility of tertiary amino groups on the microgel shell layers through a heating self-reduction method. The method is rapid in reaction and has no need of additional reducing agents; and the prepared composite material has application values in catalysis, medical diagnosis, biological imaging, drug controlled release, surface enhanced fluorescence, surface plasma resonance, sensors and other fields.

The invention provides a polymer, a pH-sensitive nano-vesicle, a preparation method and an application. The structural formula of the polymer is shown in the specification, wherein m1 + n1 is equal to9 to 19, m2 + n2 = 9-19; p = 5-10, R1 and R2 are selected from the vesicles formed by the polymer, and the particle size of the vesicles is 100-160nm. According to the present invention, with the method, the weak acid medium with the pH value of 4.5-6.8 is substantially expanded, the particle size is increased to 1.4-1.8 times, the particle size increase multiple in the neutral medium and the alkaline medium is less than 1.1 times, the mutation interval is less than 0.25 pH value, and the adjustment can be performed by adjusting the number of the pyridine groups in a side chain. The vesicle provided by the invention can realize the directional administration to the pathological cells with weak acidity.

A preparation method of physically-crosslinked chitosan-based hydrogel with efficient pH sensitivity and high mechanical strength, wherein the hydrogel is shown as the formula (I), belongs to the technical field of high-molecular functional modification synthesis of natural materials. The method comprises: taking hydroxy groups located on the surface of chitosan shown as the formula (III) as grafting sites; allowing potassium persulphate-sodium hyposulfite which is taken as a chemical initiator to be heated and decomposed to generate free radicals; on the active sites formed on chitosan, further triggering a part of monomers AAC shown as the formula (IV) and monomers DMAEMA shown as the formula (IV) to be grafted to main chains of chitosan through polymerization, while obtaining copolymermolecular chains of the two monomers, wherein the copolymer molecular chains are intermixed among macromolecular chains of chitosan grafted copolymer to form semi-interpenetrating network, thereby obtaining the hydrogel shown as the formula (I), and performing freeze drying to the hydrogel to obtain a solid product. The reaction is easy to operate, and the condition is mild. The physically-crosslinked hydrogel obtained from the preparation method is efficient in pH sensitivity, high in mechanical strength, good in biological compatibility and large in swelling rate, and has bright applicationprospects with the respect to macro-molecule solute separation, drug release systems, disease diagnosis and daily monitoring in the medical and medicine fields.

The invention relates to a pH-sensitive hydrogel and a preparation method thereof. The hydrogel is composed of carboxymethyl chitosan, polymethyl vinyl ether, crosslinking agent glutaraldehyde and water, wherein the molar ratio of carboxymethyl chitosan to polymethyl vinyl ether is 1:0.25 ~1.5; the molar ratio of crosslinking agent glutaraldehyde and carboxymethyl chitosan is 1:10~30, and the balance is water. The preparation method of the hydrogel is as follows: under stirring, carboxymethyl chitosan and polymethyl vinyl ether are dissolved in deionized water at a molar ratio of 1:0.25 to 1.5, and fully mixed, while controlling the carboxymethyl chitosan and polymethyl vinyl ether. The concentration of methyl chitosan and polymethyl vinyl ether is in the range of 0.05 ~ 0.1M; then add pentamethylene glycol dropwise to the above mixed solution according to the molar ratio of carboxymethyl chitosan to 1:10 ~ 30 The aldehyde was stirred and reacted for 30 to 60 minutes, then poured into the mold after standing still, and dried at room temperature to a constant weight to obtain a semi-interpenetrating network pH-sensitive hydrogel. The hydrogel obtained by the invention not only has good pH sensitivity, but the addition of PVME improves the shortcoming of CMCS being hard and brittle, so that the obtained material has high adhesion and softness, and this hydrogel can be degraded under certain conditions , as a sustained-release drug carrier has potential application value.

The invention relates to the pH-sensitive polyurethane and a preparation method and application thereof. The pH-sensitive polyurethane has a structure as shown in a formula I, wherein R is one of materials, m = 2-4, n1 = 20-90, n2 = 20-90, x1 = 1*10< 4>-1*10 < 6 >, and x2 = 1 * 10 < 4 >-1 * 10 < 6 >. The preparation method comprises the following steps of reacting the N, N '-dihydroxyethylpiperazine with the diisocyanate under the action of a catalyst to obtain a double-end isocyanate polyurethane prepolymer, then adding the monoene propyl group polyethylene glycol to react continuously to obtain the pH-sensitive polyurethane, wherein a main chain of a drug carrier obtained by the preparing the polyurethane contains a plurality of pH value sensitive groups, along with the change of the pHvalue of the medium, the expansion degree of the plurality of pH value sensitive groups shows the high pH sensitivity, the mutation range plurality of pH value sensitive groups is less than 0.3 pH value, and the plurality of pH value sensitive groups can be adjusted. Meanwhile, the hydrogel is relatively higher in strength and relatively longer in drug sustained release time, and the drug sustained release time can reach 1-3 weeks.