13 results about "NUCLEIC ACID SUBSTANCE" patented technology

The invention discloses a method for preparing chitosan-polyanion nanoparticles based on a microfluidic mixing technology and application. The method comprises the following steps: preparing a water phase 1 as a chitosan acidic aqueous solution, preparing a water phase 2 as a polyanion aqueous solution, and adding a surfactant; by utilizing a microfluidic device and a microfluidic mixer / chip, continuously injecting the two phases according to a set total flow rate and a flow rate ratio, and quickly mixing in a microscale channel, so that the chitosan and the polyanions are subjected to electrostatic compounding and / or ionic cross-linking to form nano-particles; the resulting dispersion is filtered to remove agglomerates and converge the particle size distribution. The aqueous phase 2 may further comprise an anionic drug or active ingredient, preferably a nucleic acid species, to produce supported nanoparticles. The obtained dispersion liquid can be stored at 0-8 DEG C for a short time, or freeze-dried after being added with a cryoprotectant to obtain powder. The process provided by the invention can be continuously amplified, and the particle size consistency and dispersion stability are improved. The nanoparticles are used to deliver the anionic drug or active ingredient into a cell or tissue.

The invention provides a nucleic acid protective agent and a preparation method and application thereof, the nucleic acid protective agent comprises a nucleic acid stabilizing main reagent, an RNA enzyme inhibitor and an antioxidant, the nucleic acid stabilizing main reagent comprises maltodextrin, xylitol and hydroxypropyl-beta-cyclodextrin; the RNA enzyme inhibitor comprises cyclopentanol and tetrahydrofurfuryl alcohol; the antioxidant comprises sodium thiosulfate, sodium pyrophosphate and ascorbic acid. According to the nucleic acid protective agent provided by the invention, free nucleic acid substances including DNA and RNA can be preserved for 2 weeks under the condition of 37 DEG C, preserved for 6 months under the condition of 2-8 DEG C and preserved for 15 months under the condition of-20 DEG C, and the degradation rate is less than 10%.

This invention belongs to the field of fluorescent dyes, specifically relating to a method for preparing a biostable compound and its applications. It exhibits high stability in both the extracellular and intracellular environments at physiological pH and temperature, making it suitable for biochemical detection and live-cell imaging. This invention also discloses that the probe can detect intracellular and extracellular nucleic acids with high specificity and responsiveness, and its application in the highly sensitive detection of mitochondrial RNA-DNA hybrids in live cells. The fluorescent probe of this invention features strong color development, good photostability, and good biostability. Furthermore, the preparation process of the fluorescent probe is simple and inexpensive, and its stable structure facilitates storage, offering broad application potential in lysosomal and mitochondrial biological function research.

This invention discloses an oxidation-responsive cationic water-soluble pillararene, a method for producing the same, and its use. The oxidation-responsive water-soluble cationic [A2]pilarene is a cyclic low-molecular-weight nucleic acid vector obtained by a quaternization reaction of a 4-methylboronic acid ester with a tertiary amine-modified pillararene. This invention achieves the synthesis of a low-molecular-weight delivery vector having a high positive charge density, which can tightly bind to negatively charged nucleic acid substances to form nanocomplexes. Upon entering a cell, the positive charge of the vector is released in an oxidative environment, the nucleic acid substance is released, and nucleic acid information is efficiently expressed. This delivery vector is easy to synthesize, has high delivery efficiency, and is biologically safe, and is expected to have promising future applications.

The present application relates to the technical fields of biological medicine and gene therapy, and particularly relates to a protonatable cationic lipid, a nucleic acid delivery system and application thereof. The protonatable cationic lipid has a structure as shown in formula (I), and contains a protonatable group such as a hydroxyl group or an amino group at the end. The protonatable cationic lipid can form a lipid nanoparticle for loading various nucleic acid substances. The lipid nanoparticle nucleic acid delivery system has high cell transfection efficiency in vitro, and can be targeted to organs such as liver in vivo to achieve efficient gene editing. The lipid nanoparticle constructed by the protonatable cationic lipid provided by the present application has high encapsulation efficiency, good stability and excellent delivery efficiency, and has a wide application prospect in the fields of gene therapy and cell engineering.

The invention provides a bioactive nanometer device and a preparation method and application thereof, the bioactive nanometer device comprises mBSG-NH2 and a nucleic acid substance loaded on the mBSG-NH2, and the mBSG-NH2 is nanometer mesoporous borosilicate bioactive glass with the surface modified with-NH2. According to the invention, the degradability of the nucleic acid delivery carrier and the protection effect on loading, enzymolysis / thermal inactivation and the like of nucleic acid substances can be improved, and meanwhile, the transmembrane delivery and intracellular lysosome escape performance of the nucleic acid substances can be improved.

The invention discloses collagen nano-microspheres as well as a preparation method and application thereof. The preparation method comprises the following raw materials in percentage by weight: 0.01 to 2 weight percent of collagen, 0.1 to 8 weight percent of nucleic acid substances, 0.001 to 5 weight percent of electropositive substances, 0.1 to 7 weight percent of auxiliaries and 78 to 99.78 weight percent of water, wherein the total mass of the raw materials is 100 weight percent; the method comprises the following steps: mixing a nucleic acid substance with partial mass of water, performing high-pressure homogenization or microjet treatment, performing low-temperature curing to obtain nucleic acid semi-solid gel, and heating and melting to obtain a phase A; dissolving collagen in the phase A to obtain a phase B; mixing the phase B and the phase C, performing high-pressure homogenization or micro-jet treatment, and adding an auxiliary agent to form collagen nano-microspheres; wherein the electropositive substance is dissolved in the balance of water in the raw materials to obtain a phase C; the collagen microspheres can improve transmembrane transport of recombinant collagen and bioavailability, and meet application requirements of the collagen microspheres in products such as transdermal drug delivery drugs.

This application relates to multiplexed methods for the identification and quantification of minor alleles and polymorphisms. Products and methods are provided for detecting the presence of minor nucleic acid substances in a sample containing a mixture of minor nucleic acid substances and one or more major nucleic acid substances, wherein the amount (frequency or copy number) of the minor nucleic acid substances is less than the amount of the major nucleic acid substances. Some methods involve amplifying the mixture and extending the resulting amplicons with a chain terminator and an extension primer that hybridizes specifically to the amplicons, wherein the chain terminator specific to the major nucleic acid substances has a lower concentration than the chain terminator specific to the minor nucleic acid substances. A higher concentration of the chain terminator specific to the minor nucleic acid substances, relative to the chain terminator specific to the major nucleic acid substances, improves the detection limit (sensitivity) for detecting minor nucleic acid substances present in the mixture at low frequency or copy number. Additionally, the signal generated from the extension product of the major nucleic acid substance amplicons can be used as a positive control and allows for the quantification of the minor nucleic acid substances relative to the major nucleic acid substances in the mixture.

1. The name of the design product: nucleic acid detection analyzer. 2. The use of the design product: the design product is used for extracting, amplifying and detecting analysis of nucleic acid substances in biological samples. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view 1.

The present application relates to the field of biological medicine, and particularly relates to a kind of targeting CD19 nanobody and its preparation method and application.The present application provides a kind of nanobody targeting CD19, nucleic acid substance encoding the above-mentioned single domain antibody, corresponding expression vector and the host cell capable of expressing the nanobody targeting CD19.The nanobody provided by the present application has excellent specific CD19 binding capacity, and the nanobody affinity can reach 3.855x10 ‑9 ‌, show that the nanobody provided by the present application has highly specific binding activity, and has important application value in the treatment of B cell malignant tumor.

The application discloses collagen nanospheres and a preparation method and application thereof. The preparation method comprises the following steps: 0.01-2wt% of collagen, 0.1-8wt% of nucleic acid substances, 0.001-5wt% of positive electric substances, 0.1-7wt% of auxiliary agents and 78-99.78wt% of water are mixed according to the total mass of the raw materials as 100wt%; the nucleic acid substances are mixed with part of the water, and after high-pressure homogenization or microjet treatment, the nucleic acid semi-solid gel is obtained by low-temperature solidification, and the A phase is obtained by heating and melting; the collagen is dissolved in the A phase to obtain the B phase; the B phase and the C phase are mixed, and after high-pressure homogenization or microjet treatment, the auxiliary agent is added to form the collagen nanospheres; and the positive electric substances are dissolved in the residual water of the raw materials to obtain the C phase. The collagen nanospheres can improve the transmembrane transportation of the recombinant collagen and improve the bioavailability, and meet the application requirements of the collagen nanospheres in transdermal drug delivery products and the like.

The invention discloses a cell culture medium for producing / preparing mesenchymal stem cell exosomes. The cell culture medium takes DMEM (Dulbecco Modified Eagle Medium) as a basic culture medium and is added with the following components: amino acids, vitamins, inorganic salts, lipids, nucleic acid substances, an EGF (Epidermal Growth Factor), a TGF (Transforming Growth Factor), a growth promoting factor, HCG (Human Chorionic Gonadotropin) and trace elements. The mesenchymal stem cell culture medium is definite in component, free of serum components, controllable in quality and capable of being produced on a large scale, and stem cells can normally grow after being cultured in vitro. Particularly, the cell culture medium for producing / preparing the mesenchymal stem cell exosome can obtain more exosomes with higher purity under the same cell culture condition. The cell culture medium is beneficial to large-scale production of mesenchymal stem cell exosomes with good biological activity, further promotes wide application of the exosomes in medical treatment, anti-aging, beauty treatment and the like, and has good economic benefits.

The invention relates to the technical field of biological medicine and gene therapy, in particular to a protonizable cationic lipid, a nucleic acid delivery system and application of the protonizable cationic lipid and the nucleic acid delivery system. The cationic lipid capable of being protonated has a structure as shown in a formula (I), and protonated groups such as hydroxyl and amino are contained at the tail end of the cationic lipid capable of being protonated. The protonizable cationic lipid can form lipid nanoparticles for entrapment of a variety of nucleic acid substances. The lipid nanoparticle nucleic acid delivery system has high cell transfection efficiency in vitro, and can be delivered to organs such as liver and the like in vivo in a targeted manner, so that efficient gene editing is realized. The lipid nanoparticles constructed by the protonizable cationic lipid provided by the invention are high in encapsulation efficiency, good in stability and excellent in delivery efficiency, and have wide application prospects in the fields of gene therapy and cell engineering.