87results about How to "Improve intake capacity" patented technology

The invention provides a PLGA (polylactic acid-hydroxyacetic acid) nano-drug carrier which is composed of PLGA nano microsphere kernel and an anillic aldehyde crosslinked chitosan housing. A preparation method of the polylactic acid-hydroxyacetic acid copolymer nano-drug carrier is as follows: dispersing a PLGA organic phase which takes dichloromethane and alcohol as a mixed solvent in a water phase to prepare PLGA microspheres by taking PVA (polyvinyl acetate) as an emulsifier by virtue of an one-off emulsion process; then, adding the PLGA microspheres into chitosan liquor, so that the chitosan is adsorbed on the surfaces of the PLGA microspheres, and then adding the chitosan on the surfaces of anillic aldehyde crosslinked PLGA microspheres. The product has a certain pH environmental responsiveness, can realize controlled release of the drug according to in-vivo pH environmental changes, is high in stability, strong in up-taking capacity for microsphere-coated medicaments by the cells, and has very good application prospect in the drug carrier for treating tumors.

The invention relates to a preparation method of carboxyl and polypeptide modified AIE polymer nanoparticles, the method comprises the following steps: 1) preparing an emulsifier aqueous solution; 2)dissolving AIE molecules and an Austrian ripening effect inhibitor in a mixed solution of carboxyl functional monomers and hydrophobic monomers to obtain an oil phase solution; 3) adding the emulsifier aqueous solution into the oil phase solution, stirring and pre-emulsifying to obtain crude emulsion, and performing ultrasonic treatment to obtain monomer miniemulsion; introducing nitrogen to remove oxygen, adding a water-soluble initiator to react; 4) dissolving a carbodiimide condensing agent in an acidic pH buffer solution, and adding the carbodiimide condensing agent into the emulsion prepared by the step 3) for activation; 5) dissolving omega-aminomaleimide in an alkaline pH buffer solution to obtain an omega-aminomaleimide solution; 6) adding the omega-aminomaleimide solution to the emulsion prepared in the step 4) for reaction; and (7) adding a polypeptide aqueous solution containing cysteine sequence units at the tail end to the emulsion prepared in the step (6) for reaction toprepare the carboxyl and polypeptide modified AIE polymer nanoparticles.

The invention provides a biologically orthogonal targeted cytomembrane biomimetic nanoparticle. The biological orthogonally targeted cytomembrane biomimetic nanoparticle is characterized by comprisinga nano core composed of a high polymer and an active ingredient and cytomembrane wrapping the nano core; a basal metabolite modified with biologically orthogonal functional groups is embedded in thecytomembrane. The basal metabolite with the biologically orthogonal functional groups is added into the basal metabolite modified with the biologically orthogonal functional groups during cell culture, and through metabolism, the basal metabolite modified with the biologically orthogonal functional groups is embedded in the cytomembrane.

Hydrophobic nanoparticles have great potential in biological analysis and biomedical application. The invention provides a simple method; a DNA nanostructure is used as a phase transition reagent; the DNA nanostructure is a DNA tetrahedral structure formed by self-assembly of four single-stranded DNAs, tail ends of three single-stranded DNAs of the four single-stranded DNAs are modified by carboxyl, the other one single-stranded DNA contains an aptamer, and the aptamer can be specifically combined with highly expressed nucleolin on a cancer cell membrane surface, so that the targeting ability of the nanoparticles is increased and the cell uptake ability is improved. The DNA tetrahedron as the phase transition reagent is non-toxic and convenient and only requires simple separation, and the high-stability and good-dispersion hydrophilic nanoparticles can be prepared.

The invention provides a polybenzoimidazole-poly (ionic liquid) cross-linked composite high temperature proton exchange membrane and a preparation method thereof, belonging to the field of polymer chemistry and high temperature proton exchange membrane fuel cell. The polybenzoimidazole-poly (ionic liquid) cross-linked composite high temperature proton exchange membrane comprises the following ingredients on weight percent: polybenzoimidazole, 55-85%; poly (ionic liquid) containing anions, 10-40%; cross-linking agent, 5%. The poly (ionic liquid) containing anions is [PBI-BuI][BF4], [PBI-BuI][TFMS] or [PBI-BuI][Tf2N]. The invention also provides a preparation method of the polybenzoimidazole-poly (ionic liquid) cross-linked composite high temperature proton exchange membrane. The proton conductivity of the polybenzoimidazole-poly (ionic liquid) cross-linked composite high temperature proton exchange membrane provided by the invention at 170 degrees centigrade is 0.0749 S / cm to 0.149 S / cm, the thickness of the membrane is 30 to 40 [mu]m.

The invention provides modified polyethyleneimine, and a preparing method and applications of the modified polyethyleneimine. The modified polyethyleneimine is prepared through modifying polyethyleneimine with different molecular weights with phenylboronic acid compounds. The modified polyethyleneimine has an active targeting property for tumor cell membranes, and can carry genes to form a gene vector composition used for gene therapy. The gene vector composition is uniform in particle size, proper in charge, stable in properties, low in cell toxicity, high in cell transfection efficiency, high in target power, and good in biocompatibility and biodegradability. The modified polyethyleneimine and the gene vector composition can be used for the gene therapy. Preparing processes of the modified polyethyleneimine and the gene vector composition are simple, high in reaction degree controllability and capable of industrial production.

The invention discloses a bionic nano-carrier as well as a preparation method and application thereof, and belongs to the technical field of pharmaceutical preparations. According to the bionic nano-carrier, cationic nanoparticles entrapping a chemotherapeutic drug serve as an inner core, and surfaces of the cationic nanoparticles are coated with a hybrid cell membrane composed of an immune cell membrane and a tumor cell membrane to serve as a shell. The bionic nano-carrier is high in targeting property and strong in uptake capacity, can enhance anti-tumor curative effect, provides a new thought for individualized and accurate treatment, and has relatively high clinical practical significance.

The invention discloses a flue-cured tobacco germ plasm cultivation method for increasing the potassium ion content of tobacco leaves. The flue-cured tobacco germ plasm cultivation method comprises the following steps: firstly, cloning a tobacco auxin inducible promoter Pcel7 according to a conventional method; secondly, artificially synthesizing gene sequences of a tobacco potassium ion outward channel TORK1, a potassium ion inward transporter NtHAK1 and a terminator Tnos; thirdly, constructing a binary plant expression vector pSH-C-T-35S-H of a PCEL7 drive negative-sense TORK1 and a CaMV35Spositive-sense NtHAK1; fourthly, transforming soil agrobacterium and a tobacco explant; and fifthly, differentiating, transplanting and detecting a transgenic tobacco plant. According to the flue-cured tobacco germ plasm cultivation method disclosed by the invention, the drain of tobacco potassium ions is reduced by inducing an auxin signal; and meanwhile, the intake of the tobacco potassium ionsis increased, so as to facilitate the increase of the potassium ion content of the tobacco leaves.

The invention provides a two-block copolymer with light and pH (potential of hydrogen) double responsiveness and a preparation method thereof. The preparation method comprises the following steps of enabling methoxy polyethylene glycol to sequentially react with succinic anhydride, 2-nitro-1,3-benzyl diol, and 2-bromoisobutyryl bromide to prepare an ATRP (atom transfer radical polymerization) macromolecular initiator containing an o-nitrobenzyl ester group; then, initiating the polymerizing of the alkyl tertiary amine acrylate monomer, so as to obtain the two-block copolymer, namely polyethylene glycol-o-nitrobenzyl ester-polyalkyl tertiary amine acrylate, wherein the o-nitrobenzyl ester group is positioned between the two blocks of the copolymer, and is used for absorbing ultraviolet light to break; the alkyl tertiary amine group has the pH responsiveness, so that the block copolymer simultaneously has the light and pH responsiveness. The two-block copolymer has the advantages that the micelle can be assembled under the neutral condition, and can be dissociated under the weak acid condition; the potential application is realized in the fields of medicine release control and gene transfection.

The invention discloses a liver-targeted platinum-loaded nanometer prodrug for treating liver cancers and a preparation method thereof. The liver-targeted platinum-loaded nanometer prodrug is prepared by taking sodium alginate with the good biocompatibility as a framework to be modified with glycyrrhetinic acid (GA) with a liver cancer cell targeting capacity and a tetravalent platinum compound (PtCl2(OH)2(NH3)2) through a self-assembly technique. In-vitro drug releasing and cytotoxicity tests prove that the platinum-loaded drug nanoparticles have the good blood stability and the intracellular slow-release effect and also have the tumor cell killing capacity. The nanometer prodrug is expected to be used for targeting treatment on the liver cancers and has a good application prospect in the biomedical field.

The invention discloses a preparation method of a targeted nano vaccine based on a metal-polyphenol network structure. The preparation method comprises the following steps that mesoporous silica nanoparticles loaded with ovalbumin OVA are prepared, mannose-modified tannic acid molecules are synthesized, and the surfaces of the mesoporous silica nanoparticles loaded with the ovalbumin OVA are coated with metal-polyphenol network coatings, so that the mesoporous silica nanoparticles loaded with the OVA and with the surfaces coated with the metal-polyphenol network coatings are obtained, therefore the targeted nano-vaccine based on the metal-polyphenol network structures is obtained, and the targeted nano-vaccine is named as MS@OVA@MPN@Man. According to the preparation method, the surfaces are coated with the metal-polyphenol network coatings, so that leakage of OVA is prevented, and the lysosome escape function of the nanoparticles is increased; and meanwhile, mannose is modified on thesurface to target a mannose receptor on the surface of an immune cell, so that the uptake capacity of the cell to the mannose receptor is enhanced to improve the vaccine delivery efficiency, and the problems of targeting of the nano vaccine and lysosome escape efficiency are solved.

The invention discloses a docetaxel transferrin acceptor-targeted liposome preparation. The preparation is prepared with a preparation method comprising the following steps of: mixing 55-95 parts by weight of phospholipid, 3-40 parts by weight of cholesterol and 0.05-20 parts by weight of docetaxel; dissolving into ethanol; performing rotary evaporation; adding 0.5-1.5ml of a phosphate buffer solution, and hydrating to obtain a liposome; and connecting a transferrin ligand to a liposome surface which contains docetaxel by applying a backward embedding technology to obtain a docetaxel transferrin acceptor-targeted liposome preparation, wherein the average particle diameter of the preparation is 60-100 nanometers, and the interfacial potential is -10mV to 20mV. As proved by a cytotoxicity research result, compared with a non-targeted liposome, a transferrin acceptor-targeted liposome has the advantage that: the toxicity of docetaxel on KB cells can be enhanced remarkably. The docetaxel transferrin acceptor-targeted liposome disclosed by the invention can become a novel medicament preparation for treatment cancers in future.

The invention relates to a tumor targeted polypeptide-adriamycin amycin derivative as well as a preparation method and application thereof. The compound is prepared by virtue of the following steps: dissolving polypeptide in a phosphate buffer solution with the pH value of 7.8-8.2; then, dissolving DOXO-EMCH in a solvent to obtain a solution, wherein the polypeptide is T10 peptide or T15 peptide and the solvent is a mixture of water and N,N'-dimethylformamide; dropwise adding the DOXO-EMCH solution into a polypeptide solution; stirring and reacting away from sunlight at room temperature; then, centrifugalizing the solution to remove precipitate to obtain a coarse product; separating and purifying the coarse product by preparative chromatography, and centrifugalizing and concentrating to obtain a fine product T10-DOX-EMCH or T15-DOX-EMCH. According to the adriamycin amycin hydrazone compound provided by the invention, the hydrazone bond is selectively broken in an acidic microenvironment of tumor to release adriamycin amycin with pharmacological activity, so that the curative effect of medicine is improved and the drug tolerance of tumor is reversed.

The invention discloses a redox-sensitive hyaluronic acid-docetaxel conjugate and a preparation method thereof. The redox-sensitive hyaluronic acid-docetaxel conjugate is prepared by the following steps: mixing a raw material medicine with a connection body, dissolving the mixture into an organic solvent, adding an acid-binding agent, stirring under room temperature, and performing vacuum spinning steaming to remove the organic solvent; after purification is executed, dissolving a product into a proper amount of the solvent, adding an activating agent and a dewatering agent for activation under room temperature to generate anhydride activation ester serving as the raw material medicine; dissolving a carrier into a solution, and adding the activating agent and the dewatering agent for stirring activation; after activation is executed, adding a disulfide bond crosslinking agent, performing dialysis, dry-freezing to obtain a product; dissolving a carrier crosslinking product into the organic solvent; dripping the anhydride activation ester serving as the raw material medicine into a carrier solution, incubating for certain time, performing dialysis, and dry-freezing to obtain the target product. The conjugate prepared by the invention can effectively improve the solubility of docetaxel; the redox-sensitive hyaluronic acid-docetaxel conjugate is higher in targeting property and has the advantages of simple preparation method, low cost and the like.

The invention provides a target polypeptide modified positive ion copolymer gene vector, a preparation method and application. The preparation method comprises the steps of preparing a PCLMD-g-PEI copolymer; grafting the PCLMD-g-PEI to the target polypeptide to prepare the gene vector. The vector and a pDNA solution are mixed, and a gene composition is prepared. The obtained gene vector has low cell toxicity, when the target polypeptide is a step-by-step target polypeptide REDV-G-TAT-G-NLS, the vector has the ECs adhesion function, the cell membrane target function and the cell nucleus targetfunction, on the basis of the specific proton effect of the PEI, the gene composition has the endosome / lysosome escape function, and therefore the gene transfer effect is improved, the transfection efficiency is improved, and cell migration and proliferation are promoted.

The invention provides an organic-inorganic composite type high-temperature proton exchange membrane used for a fuel cell and a preparation method for the proton exchange membrane, and belongs to the field of high polymer chemistry and high-temperature proton exchange membrane fuel cells. The proton exchange membrane is prepared from the following components based on weight percentages: 3-12% of ionic liquid functionalized silicon dioxide precursor and 88-97% of siloxane side base-containing polybenzimidazole; and the structural formulas of the ionic liquid functionalized silicon dioxide precursor and the siloxane side base-containing polybenzimidazole are as shown in the formulas I and II as follows respectively. The invention also provides the preparation method for the organic-inorganic composite type high-temperature proton exchange membrane used for the fuel cell. The proton conductivity of the organic-inorganic composite type high-temperature proton exchange membrane at a temperature of 170 DEG C is 0.050-0.075S / cm; and the thickness of the organic-inorganic composite type high-temperature proton exchange membrane is 30-50[mu[m.

The invention provides a preparation method for a carboxyl and polypeptide modified AIE polymer nanoparticle. The preparation method comprises the following steps: 1) preparing an emulsifier aqueous solution; 2) dissolving an AIE molecule, an Ostwald ripening effect inhibitor and an oil-soluble initiator into a mixed solution of a carboxyl functional monomer and a hydrophobic monomer so as to obtain an oil-phase solution; 3) adding the emulsifier aqueous solution into the oil-phase solution, carrying out pre-emulsification under stirring so as to obtain a crude emulsion, carrying out ultrasonic treatment so as to prepare a monomer fine emulsion, and introducing nitrogen to remove oxygen so as to prepare a carboxyl modified AIE polymer nanoparticle emulsion; 4) dissolving a carbodiimide condensing agent into an acidic pH buffer solution, adding an obtained solution into the emulsion prepared in the step 3), and carrying out an activation reaction; 5) dissolving omega-aminomaleimide intoan alkaline pH buffer solution; 6) adding an omega-aminomaleimide solution into an emulsion prepared in the step 4), and carrying out a reaction; and 7) adding a polypeptide aqueous solution with theterminal containing a cysteine sequence unit into an emulsion prepared in the step 6), and carrying out a reaction so as to prepare the carboxyl and polypeptide modified AIE polymer nanoparticle.

The invention relates to a preparation method of amino and polypeptide modified AIE polymer nanoparticles, the preparation method comprises the following steps of: 1) dissolving an emulsifier and an amino functional monomer in water to obtain an aqueous phase solution; 2) dissolving AIE molecules and an Austrian ripening effect inhibitor in a hydrophobic monomer to obtain an oil phase solution; 3)adding the aqueous phase solution into the oil phase solution, stirring and pre-emulsifying to obtain crude emulsion, and performing ultrasonic treatment to obtain monomer miniemulsion; introducing nitrogen to remove oxygen, adding a water-soluble initiator to react to prepare amino modified AIE polymer nanoparticle emulsion; 4) dissolving omega-maleimide alkyl acid and a carbodiimide condensingagent in an acidic pH buffer solution for activation to obtain an activated intermediate solution; 5) adding the activated intermediate solution into the emulsion prepared in the step 3) to react to prepare maleimide modified AIE polymer nanoparticle emulsion; and 6) adding an aqueous solution of a polypeptide containing cysteine sequence units at the end to the emulsion prepared in the step 5) for reaction to obtain the amino and polypeptide modified AIE polymer nanoparticles.

A brake negative pressure control device for a vehicle includes an ECU. The ECU is configured to (i) control a first fuel injection valve and a second fuel injection valve, when the ECU determines that a negative pressure in a negative pressure chamber is insufficient, such that a ratio of a fuel injection amount by the first fuel injection valve is decreased and a ratio of a fuel injection amount by the second fuel injection valve is increased; and (ii) control an opening degree of the throttle valve, when the ECU determines that the negative pressure in the negative pressure chamber is insufficient, such that the opening degree of the throttle valve at the time when the ECU determines that the negative pressure is insufficient is smaller than an opening degree of the throttle valve at the time when the ECU determines that the negative pressure is not insufficient.

The invention discloses a preparation method and applications of hollow gold nanospheres modified by CpG oligodeoxynucleotide. Cobalt chloride is subjected to reduction by adopting sodium borohydride,thus cobalt nanoparticles are obtained, cobalt nanoparticles are adopted for carrying out reduction on chloroauric acid, and thus hollow gold nanospheres are prepared; CpG oligodeoxynucleotide, a surfactant and a buffer solution are added into a solution of the hollow gold nanospheres, shaking culture is carried out, and thus the hollow gold nanosphere material modified by CpG oligodeoxynucleotide is obtained. According to the technical scheme, by utilizing the property that the hollow gold nanospheres have the large loading capacity, CpG is loaded through the self-assembly effect, the synthesis method is simple, and the method is suitable for large-scale production and application; the cell uptake capacity of CpG oligodeoxynucleotide can be enhanced, and the biocompatibility is good; thehollow gold nanospheres modified by CpG oligodeoxynucleotide have the near-infrared surface plasma adsorbing effect, the primary tumor is eliminated by utilizing the photothermal ablation effect, a tumor antigen is generated in situ, under the promoting of CpG oligodeoxynucleotide, the antitumor immunity of the whole body is induced, and the distant metastasis tumor is further treated.

The invention discloses a ternary gene delivery system based on cell-penetrating peptide and applications of the ternary gene delivery system. The ternary gene delivery system based on the cell-penetrating peptide is prepared by adopting the following method: multifunctional polypeptide REDV-G-TAT-G-NLG-C is connected to eight active sites of octa ammonium POSS (polyhedral oligomeric silsesquioxane) through orthopyridyl disulfide-PEG-NHS ester, and thus a star polymer is formed; the star polymer with positive charges and a gene with negative electricity are bonded through electrostatic interaction, and thus a binary gene delivery system with negative electricity on the surface is formed; a polypeptide sequence rich in histidine and the binary gene delivery system are bonded through electrostatic interaction, and thus the ternary gene delivery system is formed. The ternary gene delivery system based on cell-penetrating peptide provided by the invention has targeting ability for endothelial cells, and has the functions of cell-penetrating peptide, histidine and nuclear localization signals, so that carried genes can efficiently enter cells, the escape from endosome is effectively carried out, the entering of the genes into the cell nucleus is realized, and finally, the gene delivery effect is greatly improved.

A method for preparing amino acid-and-polypeptide-modified AIE polymer nanoparticles comprises the following steps: (1) dissolving an emulsifier and an amino functional monomer in water to obtain an aqueous solution; (2) dissolving an AIE molecule, an Ostwald ripening effect inhibitor and an oil-soluble initiator in a hydrophobic monomer to obtain an oil phase solution; (3) adding the aqueous solution to the oil phase solution, stirring and pre-emulsifying the obtained mixture to obtain a crude emulsion, carrying out ultrasonic treatment to obtain a fine monomer emulsion, introducing nitrogento remove oxygen, and carrying out a reaction to produce an amino-modified AIE polymer nanoparticle emulsion; (4) dissolving omega-maleimido alkyl acid and a carbodiimide condensing agent in an acidicpH buffer solution, and performing activation to obtain an activated intermediate solution; (5) adding the activated intermediate solution to the emulsion prepared in step (3), and carrying out a reaction to obtain a maleimide-modified AIE polymer nanoparticle emulsion; and (6) adding an aqueous solution of a polypeptide containing a cysteine sequence unit at the end to the emulsion prepared in step (5), and carrying out a reaction to produce the amino acid-and-polypeptide-modified AIE polymer nanoparticles.

The invention discloses a quinoline thiocarbamide-pyridine organic compound and preparation method and application thereof, wherein the structural formula is shown in the description, the thiosemicarbazide is combined with the quinoline group, so that the novel compound has multiple advantages of thiophanate, quinoline and pyridine pharmacophore, and possesses different types of pharmacodynamic groups and diverse structural characteristics, is beneficial to reducing the toxic and side effects of single functional group in the field of biological activity, and the compounds is endowed with multiple biological targets, the water solubility of the organic compound is optimized and the uptake ability of the focus tissue is improved. The thiourea, the nitrogen heterocyclic group pyridine and the quinoline are combined into an organic compound molecule, thereby being favorable for constructing the metal organic complex with different structural characteristics from the metal center, and further optimizing the biological performance thereof.

The invention discloses an application of 2',4'-dihydroxyl-6'-methoxyl-3',5'-dimethyl chalcone as an agonist of PPAR-gamma of a peroxisome growth factor; the application of the compound as the agonist of the PPAR-gamma provides a novel drug for preventing and treating type II diabetes, hyperlipemia and adiposity.

The invention discloses a magnetic targeting cell membrane modified ligand, a drug-loading material, a preparation method of the magnetic targeting cell membrane modified ligand and the drug-loading material and an application of the drug-loading material. The structural general formula of the magnetic targeting cell membrane modified ligand is shown as I series or II series in the formula (1). The magnetic targeting cell membrane drug-loading material is obtained by performing chemical covalent bond modification on a cell membrane to modify the magnetic targeting cell membrane modified ligand, an in-vitro test shows that the material is good in stability, can be effectively taken in by tumor cells, and has relatively high selectivity on the tumor cells, and besides, the material has remarkable paramagnetism. Under the condition of an external magnetic field, a magnetic targeting effect can be achieved. In an in-vitro anti-tumor test, the drug-loading material is remarkable in anti-tumor activity and hardly has toxicity to normal cells, so that the drug-loading material has a potential application of targeted therapy of malignant tumors.

The invention discloses a protein-polymer composite nanomaterial gene vector as well as a preparation method and application thereof. The vector is obtained by performing in-situ polymerization on a macromolecular shell on the surface of protein and synthesizing a nano material with a core-shell structure. The vector can effectively compound and compress nucleic acid, can protect the nucleic acid from being degraded by nuclease, can efficiently release the nucleic acid into cytoplasm through degradation of cationic groups in a polymer shell layer, achieves extremely high gene transfection efficiency, has high biocompatibility, low cytotoxicity and designable functionality, the preparation process and the purification process are simple, and the method has a wide application prospect in the related fields of gene therapy.

The invention discloses a bionic bismuth nanoflower as well as a preparation method and application thereof, and belongs to the technical field of medicines. The bionic bismuth nanoflower comprises a cell membrane and a bismuth nanoflower body, and the cell membrane serves as a shell to wrap the surface of the bismuth nanoflower body. The bionic bismuth nanoflower disclosed by the invention not only has good biological safety and physiological environment degradability, but also has the characteristics of good NIR II photo-thermal conversion efficiency, radiotherapy sensitization and CT / PAI dual-mode imaging, and is a novel diagnosis and treatment integrated carrier integrating photo-thermal and radiotherapy.

The invention discloses a preparation method and application of nanoparticles of a ribonucleoprotein compound capable of achieving tumor targeted delivery. The nanoparticles are formed by self-assembly of a polymer with tumor microenvironment responsiveness and the ribonucleoprotein compound, the polymer with tumor microenvironment responsiveness allows the nanoparticles to maintain stability in the blood circulation process, and meanwhile the enrichment of the nanoparticles in tumor tissue is enhanced. The nanoparticles of the ribonucleoprotein compound carrying fluorescent probe marks are injected to mice with tumor, the effective enrichment of the ribonucleoprotein compound in the tumor tissue is achieved, and it is indicated that the delivery of the ribonucleoprotein compound with tumor targeted delivery can be completely achieved by the nanoparticles.

The invention discloses a preparation method of PEI-CDs (polyetherimide-carbon dots) capable of emitting orange fluorescence. The preparation method comprises the steps that tetramethyl benzidine (TMB) and PEI are subjected to ultrasonic treatment until TMB and PEI are completely dissolved, then the mixture is transferred into a high-pressure reaction kettle and subjected to a reaction, and PEI modified CDs are synthesized by a hydrothermal method by one step; and after the PEI modified CDs are cooled to the room temperature, an obtained PEI-CDs stock solution is dialyzed by a dialysis bag andsubjected to rotary evaporation and concentration, system polarity reduction and petroleum ether precipitation, PEI-CDs precipitates are obtained, washed and subjected to vacuum drying, and solid PEI-CDs are obtained. The synthesis technology is simple, the cost is low, the yield is high, and the post-treatment method is novel. The synthesized PEI-CDs have good water solubility, high stability and particle uniformity, emit orange fluorescence under excitation of a visible light source, have high cell safety and high cellular uptake capacity, and can effectively transmit SiRNA to cross biological membranes to enter cells.