69results about How to "Improve gene transfection efficiency" patented technology

The invention relates to a modification method of functional plant polysaccharide, which comprises extracting functional polysaccharide from the plant with biological activity, separating, purifying and determining molecular weight and biological function, modifying structure via agent, activating active hydroxyl on sugar chain, connecting small molecule polyethylene imine, dialyzing, freezing and drying to obtain functional plant polysaccharide. The modification method has simple process, high efficiency and high yield, which keeps prior activity of natural polysaccharide and adds new biological function to obtain a natural macromolecule compound as non-viral gene carrier.

The invention discloses a non-viral gene carrier of autofluorescence degradable poly-citrate and a preparation method thereof. Citric acid, 1,8-octylene glycol and polyethylene glycol are subjected to thermal polymerization to obtain a POCG prepolymer; then, the POCG and PEI (polyethyleneimine) are subjected to catalytic polymerization to obtain a POCG-PEI polymer; the POCG-PEI polymer and various genes (DNA/siRNA/miRNA) can form a stable nanocomposite in HEPES buffer liquid. The used thermal polymerization method has the advantages that the environment is protected; the operation is convenient; the raw material cost is low. The prepared POCG-PEI has good biocompatibility and high gene transfection efficiency; meanwhile, the POCG-PEI also shows certain fluorescence characteristics and optical stability, so that the polymer has good application prospects in the gene treatment process.

The invention discloses a class of near infrared fluorescent dyes, a targeted imaging agent thereof, a nanocarrier, an anticancer drug and an application. The near-infrared fluorescent dyes and hydrophilic dendrimers are linked by environmentally sensitive bonds to form amphiphilic dendrimers with self-assembly capability. The hydrophilic dendrimers have good tumor targeting performance and transmembrane performance when lysine and arginine are used as backbone structures. The amphiphilic dendrimers also have nitroreductase responsiveness and can be self-assembled into nanoliposomes or micelles or vesicles for gene and/or drug carriers that are disassembled in the tumor microenvironment to release genes and/or drugs for therapeutic purposes. The amphiphilic dendrimers can also produce reactive oxygen in near infrared light and can be used in photodynamic therapy. The dendrimers are fluorescence quenched before and after self-assembly and after disassembly, and can generate fluorescenceenhancement only under the action of nitroreductase of tumor cells. The penetrating capability is higher, and the penetrating is more precise.

The invention relates to the field of chemistry and preparations, in particular to an unsaturated cationic lipid derivative, a preparation method thereof, and application in a plasmid delivery system.The cationic lipid takes electropositive lysine as a hydrophilic head group, amino acid as a skeleton and an unsaturated alkane chain as a hydrophobic tail chain, so that the cationic lipid has the advantages of good biocompatibility, high safety and the like. The synthesis method is simple and quick, low in synthesis cost and beneficial to large-scale production. The cationic liposome constructed on the basis of the unsaturated cationic lipid designed by the invention can stabilize the load plasmid without leakage, has better gene transfection efficiency on various tumor cells and primary cells than positive control Liponectamine2000, and has no obvious cytotoxic effect on cells. The invention provides a safe and efficient cationic lipid and non-viral vector platform for plasmid delivery.

The invention provides a microenvironment double-response chitosan gene carrier as well as a preparation method and application thereof. The method is started from oligosaccharides of chitosan, and synthesizes macromolecular chitosan (SRCS) containing an acylhydrazone bond and a disulfide bond. The method adopts a covalent grafting method to carry out polyethyleneimine (PEI) grafting and polyethylene glycol (PEG) grafting on the SRCS, thus obtaining oxidation reduction microenvironment and acid microenvironment double-response SRCS-g-PEI-g-PEG polymer. The SRCS-g-PEI-g-PEG polymer prepared by the invention has performance of microenvironment double-response gene release control. The invention also provides the application of the SRCS-g-PEI-g-PEG polymer obtained by the method as a gene carrier in gene transfection; the SRCS-g-PEI-g-PEG polymer has good biocompatibility and high gene transfection efficiency, thus being a good carrier for gene transfection and having a wide application prospect.

The present invention discloses a macrocyclic polyamine coupled chitosan gene vector, preparation method and uses thereof. General formula of the gene vector is as follows, wherein the R[1], R[2] represents macrocyclic polyamine compounds or H, the macrocyclic polyamine is coupled to second amidogen of the chitosan in amide linkage or coupled to sixth hydroxy of the chitosan in ester linkage. The invention is obtained by using EDAC as condensing agent to couple the macrocyclic polyamine at the second position of the chitosan macromolecular skeleton, or using BOP reagent as ester condensing agent to couple the macrocyclic polyamine at the sixth position. The macrocyclic polyamine coupled chitosan compounds can be used as non-viral gene vector for cell transfection to cure various genopathy. The invention applies gel electrophoresis method to study combination and protection effect of target compounds to DNA, and provides good basement and effective approach for obtaining non-viral gene vector with low cytotoxicity and high transfection efficiency.

The invention provides a novel gene transfection vector based on low-algebraic polyamidoamine. The gene transfection vector comprises low-algebraic polyamidoamine and a difunctional cross-linking agent which contains a disulfide bond and of which the reaction points to amino, wherein a primary amine group of the low-algebraic polyamidoamine is reacted and connected with active groups at two ends of the difunctional cross-linking agent. The invention also provides a method for preparing the gene transfection vector and application of the gene transfection vector which is used as a nucleic acid molecule delivery vector in vivo or in vitro. The gene transfection vector is low in synthetic cost and small in cytotoxicity, can deliver gene molecules to cells effectively and safely and can be used as the gene transfection vector which has the advantages of high efficiency, low toxicity, low cost and the like.

The invention provides a polycarboxyl glycine betaine gene transfection preparation as well as a preparation method and an application thereof. The polycarboxyl glycine betaine gene transfection preparation comprises a gene transfection reagent based on polycarboxyl glycine betaine molecules, and nucleic acid to be subjected to transfection, wherein the gene transfection reagent based on polycarboxyl glycine betaine molecules comprises polycarboxyl glycine betaine polymer, a compound buffer solution and a gene transfection working solution. The gene transfection preparation has the excellent non-specific protein adsorption resisting property, high gene transfection efficiency, as well as pH responsibility, and significant blood stability, the gene transfection efficiency of nucleic acid is obviously improved, and the polycarboxyl glycine betaine gene transfection preparation can be applied to various research fields including gene therapy, gene function, biological pharmacy, drug screening and the like.

The invention discloses a polymethacrylamide cationic polymer cooperatively modified by side groups natural arginine and lactobionic acid, a preparation method and application thereof as a gene carrier. A methacrylamide cation functional polymer with amino as a side group is synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization and subsequent deprotection reaction, then arginine containing a protective group and a lactobionic acid building block are linked to a polymethacrylamide molecule, and finally the protective group is removed for obtaining the target polymer. The preparation method of the polymethacrylamide cationic polymer is simple and mild in reaction conditions. Cell evaluation results show that the prepared polymethacrylamide cationic polymer cooperatively modified by side groups natural arginine and lactobionic acid has high biological compatibility, low cytotoxicity, high gene transfection efficiency and good serum stability, and is an effective novel glycosyl-modified non-virogene carrier, and is applicable as an efficient gene transfection reagent.

The invention discloses a magnetic nanometer gene vector system as well as a preparation method and an application thereof. The gene vector system comprises electronegative magnetic nanoparticles, positive-ion vectors and genes, wherein the three components are prepared into the magnetic nanometer gene vector system according to certain proportions and composite sequences through electrostatic interactions. The magnetic nanometer gene vector system disclosed by the invention is simple in preparation method and has physicochemical properties of small grain diameter and proper surface charge. Compared with non-magnetic nanometer composites, the magnetic nanometer gene vector system has the advantages that the transfection efficiency to cells of the system is remarkably improved under the action of an additional magnetic field; and meanwhile, the cytotoxicity of the system is further reduced.

The invention discloses a lipopolysaccharide amine cationic polymer, which is synthesized with hydrophilic polyaldehyde-based sodium alginate is adopted as a main chain, hydrophobic cholesterol capped polyethylene imine of low molecular weight as a side chain. The physical and chemical structure, buffering capacity, transfection efficiency and cytotoxicity of the lipopolysaccharide amine cationic polymer are characterized. According to exploration of the feasibility of use as a gene carrier and the effects on improvement of the gene transfection efficiency and reduction of the cytotoxicity, the polymer has advantages of good biocompatibility, controllable degradation performance, low cytotoxicity, high safety and practicality and low cost, and the transfection efficiency of GFP (green fluorescent protein) in MSCs (mesenchymal stem cells) is higher than 95 percent regardless of the presence or absence of serum. Moreover, the polymer can be used as a gene carrier and other drug carriers such as anticancer drugs, RNA (ribose nucleic acid) carriers and the like. The invention also discloses a preparation method and application of the polymer.

The invention discloses a near infrared fluorescent dye taking a fluorophore of a cyanine dye as a parent skeleton structure and a preparation method and the application of the near infrared fluorescent dye, and belongs to the field of biomedical materials. The photostability of the near infrared fluorescent dye is better and the fluorescence quantum yield of the near infrared fluorescent dye is high as a cyclic hydrocarbon group is inserted into a long methenyl chain. The near infrared fluorescent dye can serve as a hydrophobic end to be combined with a hydrophilic molecule with good biocompatibility through an environment sensitive bond and self-assembled to form a nanoscale lipidosome or a micelle or a vesicle. An obtained lipid material can be mixed with a medicine and\or a gene and self-assembled to form the lipidsome or the micelle or the vesicle, and the medicine and\or the gene are\is coated inside to form a carrier system. The carrier system at the luminescence quenching state enters a target cell, the environment sensitive bond on the material is fractured and disassembled in the specific environment, the medicine and\or the gene are\is released to play a role in treatment, moreover, the cyanine dye gathered inside is also released, the fluorescence is recovered. Therefore, the fluorescence switching function is realized, and the integration of diagnosis and treatment is further realized.

The invention discloses a modified polyhydroxyethyl acrylamide transgenic vector. Polyhydroxyethyl acrylamide is taken as a framework structure; and a side-chain substituent R of the polyhydroxyethyl acrylamide is NH2(CH2)n1N(CH2)n2NH2, wherein n1 is 1 to 5 and n2 is 1 to 5. A preparation method comprises the following steps of: preparing the polyhydroxyethyl acrylamide through atom transfer radical polymerization, protecting primary amine of a small molecular modifier by using trifluoroacetic acid ethyl ester, grafting the primary amine onto the polyhydroxyethyl acrylamide, and finally performing deprotection to obtain the transgenic vector. Cationized polyhydroxyethyl acrylamide is convenient for cell internalization and can protect deoxyribonucleic acid (DNA) from being degraded by DNase, so that the vector can enter cells, and then the DNA is released.

The invention discloses a triblock copolymer polyethyleneimine (PEI)-polyethylene glycol (PEG)-PEI, belonging to the field of gene drug carriers. The triblock copolymer PEI-PEG-PEI has the structural formula as shown in the specifications. A PEI-PEG copolymer synthesized by the technical scheme of the invention has the characteristics of high transfection efficiency and low cytotoxicity, and has a wide application prospect.

The invention relates to the field of lipidosome gene transfection biological reagents, and particularly relates to an organic functional molecule containing natural cholesterol and lysine lipid cations, the lipidosome thereof, a preparation method, and an application for the lipidosome as a small interfering RNA (ribonucleic acid) (SiRNA) transfection reagent. The organic functional molecule containing natural cholesterol and lysine lipid cations provided by the invention is simple in synthesis method and high in efficiency; the lipidosome formed by compounding the organic functional molecule with auxiliary lipid dioleoyl phosphatidyl ethanolamine (DOPE) is simple and convenient in preparation method, and easy to realize large-scale preparation. As the SiRNA gene transfection reagent, the lipidosome containing natural cholesterol and lysine lipid cations provided by the invention is obviously low in cytotoxicity compared with the commercially available commercialized gene transfection reagent bPEI-25 k, relatively efficient in SiRNA gene transfection effect, and capable of being applied in SiRNA transfection as a novel lipid gene carrier functional reagent.

The invention discloses preparation methods and application of a novel ortho-ester monomer and an acid-sensitive polymeric gene carrier thereof. A polymer carrier transmission system prepared by the methods has controllable acid degradation rate, relatively low cytotoxicity and relatively high gene transfection efficiency and is a non-viral polymeric gene carrier which has a good application prospect.

The invention discloses a respiratory tract homing siRNA atomizing nanometer drug delivery system which uses salbutamol guanidinated chitosan treated by ultrasonic atomization as a carrier material, and is prepared by wrapping siRNA which interferes with target pathogenic genes. The invention also discloses a preparation method of the respiratory tract homing siRNA atomizing nanometer drug delivery system. The drug delivery system disclosed by the invention can be used to deliver siRNA which interferes with target pathogenic genes so as to play an RNA interference role and inhibit the replication of the pathogenic genes, can deliver siRNA with the target of lung respiratory tract epithelia in vivo, and is a non-virus delivery system which exerts corresponding drug effect by aiming at silence the target genes.

The invention relates to the field of cationic liposome small interference RNA (SiRNA) transfection reagents, in particular to cationic liposome containing natural yam sterols, a preparation method of the cationic liposome, and application of the cationic liposome as an SiRNA transfection reagent. The cationic liposome containing natural yam sterols, provided by the invention, is formed by direct ultrasonic hydration after compounding of the cationic liposome containing natural yam sterols and auxiliary lipid dioleoyl phosphatidyl ethanolamine, the preparation method is simple and convenient, and large-scale preparation is easy to realize. Compared with a commercial gene transfection reagent bPEI-25k sold on the market, the cationic liposome as the SiRNA transfection reagent has remarkable lower cytotoxicity, a relatively efficient SiRNA transfection effect, and can be taken as a novel lipoid gene vector functional reagent to be applied to SiRNA transfection.

The invention discloses a freeze-drying preparation of a ternary gene transfer system and a preparation method thereof. The preparation method comprises the following steps of using 3-aminopropyltriethoxysilane to perform aminated modification on mesoporous silicon dioxide nanoparticles, so as to obtain MSHs-NH2; hatching the MSHs-NH2, DNA (deoxyribonucleic acid) and a cationic polymer carrier solution, and building the ternary gene transfer system; freezing and drying by a freeze-drying protection agent, so as to obtain the freeze-drying preparation of the ternary gene transfer system. The freeze-drying preparation of the ternary gene transfer system has the advantages that the transfection efficiency is higher, and the toxicity risk in body is decreased; the obvious antiserum transfection characteristic is realized, the transfection activity is better, the liquid preparation can be cured, the long-time storage under the non-cold chain condition is realized, and the stability and transfection activity are maintained.

The invention discloses a cellulose nanocrystal-polyethylenimine nano-compound gene carrier and a preparation method thereof. The cellulose nanocrystal-polyethylenimine nano-compound gene carrier comprises a cellulose nanocrystal inner core and a polyethylenimine shell layer covering the inner core, wherein the cellulose nanocrystal inner core and the polyethylenimine shell layer interacts with each other through electrostatic attraction so as to be tightly combined with each other. The gene carrier disclosed by the invention has the advantages of good biocompatibility and high gene transfection efficiency; moreover, the toxicity of the carrier is reduced, the gene carrier can be recycled, and the gene transfection cost can be reduced. In addition, the preparation method is simple and is low in cost.

The invention discloses an adenovirus vector-mediated gene transfection method for stereoscopic-state tooth germ ameloblasts. The method comprises the following steps that: a separated primary tooth germ with an upward cusp is placed on a microporous filter membrane of a Transwell built-in cabinet and is cultured in a culture medium containing the tooth germ; infectious viral particles containing an AAV-GFP gene are used to infect the cultured tooth germ; green fluorescence appears on a surface layer of the tooth germ 24 hours after infection; in combination with the immunostaining of amelogenin, recombinant tooth germ ameloblasts co-expressed by GFP and the amelogenin are positioned on the tooth germ. The ameloblasts of the Transwell-system in vitro cultured tooth germ maintain a stereoscopic state and have interaction with surrounding matrixes and related cells, and the gene transfection success of the ameloblasts in the mode is favorable for researching the gene function of the ameloblasts in the tooth germ from a three-dimensional perspective.

The invention provides a gene transfection vector based on a dendrimer skeleton and a nucleic acid basic group as shown in a formula (1). The gene transfection vector comprises a dendrimer and a nucleic acid base derivative, wherein the nucleic acid base derivative is in covalent linkage with the surface of the dendrimer. The invention also provides a preparation method of the gene transfection vector shown in the formula (1) and application as a nucleic acid molecule delivery vector. The gene transfection vector provided by the invention is low in synthesis cost and small in cell toxicity, can effectively and safely convey genetic molecules into cells, can be used as the gene transfection vector with the advantages of high efficiency, low toxicity, low cost and the like, and has good application prospect.