62 results about "Dna nanostructure" patented technology

The present invention provides DNA-nanostructures comprising and at least one targeting moiety, wherein the at least one targeting moiety is linked to the DNA-nanostructure; and wherein the at least one targeting moiety is nicotine or a nicotine analogue. These compounds elicit an immunogenic response in individuals and are useful as vaccines for ameliorating nicotine dependence.

The present invention provides a ligand-nucleic acid nanostructure that promotes cell-cell interaction. Specially, the invention provides a ligand-nucleic acid nanostructure for treating tumor in a mammal. The methods of using and making the composition comprising a ligand-nucleic acid nanostructure are also provided.

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 present invention provides compositions comprising a DNA-nanostructure and at least one targeting moiety, wherein the at least one targeting moiety is linked to the DNA-nanostructure; and wherein the at least one targeting moiety is selected from the group consisting of antigens, aptamers, shRNAs and combinations thereof, and methods of use thereof.

The invention discloses a highly sensitive and decomposable quantum dot nanosphere probe and a preparation method thereof. Through a fulcrum-mediated strand displacement reaction, a DNA hairpin probe modified by three desulfated biotins is self-assembled into a Y-type DNA nanostructure; and the Y-type DNA structure and quantum dots coupled to streptavidin are self-assembled to form the quantum dot nanosphere probe. The prepared quantum dot nanosphere probe and an immunomagnetic separation technology are combined to be applied to quick detection of a target analyte. Because of a binding force between biotin and streptavidin stronger thana binding force of desulfurized biotin, the quantum dot nanosphere probe is decomposed, and thus quantum dots are released; the target analyte concentration is determined by detecting the fluorescence value of a quantum dot solution, and a shielding effect of immunomagnetic beads on the quantum dots is overcome. The method has high sensitivity and the detection limit of microorganisms is 1.37 cfu/mL. This method is good in specificity, and common other microorganisms do not affect the detection.

The invention discloses a DNA nanostructure, an electrochemical aptamer biosensor system as well as a preparation method and application of the electrochemical aptamer biosensor system, and relates tothe field of food-borne pathogenic bacteria detection. A stable DNA nanostructure is synthesized through a rolling circle amplification reaction, and heme is loaded to serve as an electrochemical signal label to amplify a signal; the single-stranded DNA capture probe is modified on the surface of the Au electrode through an Au-S bond; the food-borne pathogenic bacteria specific aptamer and the capture probe form a double-stranded DNA structure on the Au electrode; the aptamer is preferentially combined with the food-borne pathogenic bacteria, so that the aptamer-capture probe double-chain body is dissociated, and the capture probe is released; the free capture probe is hybridized with the DNA nanostructure through a complementary DNA sequence; and the concentration of the food-borne pathogenic bacteria is quantitatively determined through an electrochemical signal of a DPV method. The method is simple, rapid, easy to operate, low in experiment cost, sensitive, high in specificity andgood in application prospect.

The invention discloses a multi-color fluorescent probe based on a DNA nanostructure as well as a preparation method and application thereof. The method comprises the following steps: constructing DNAtetrahedrons with different arm chain numbers; constructing a DNA nano self-assembly structure by a strategy of layer-by-layer assembly or fractal assembly, and marking fluorescent molecules of different types and quantities on the DNA nano self-assembly structure so as to construct the multicolor fluorescent probe based on the DNA nano self-assembly structure. According to the invention, the small-size multicolor fluorescent probe is constructed by a self-assembly means from bottom to top, and the defects of low coding quantity and uncontrollable optical property of the traditional fluorescent label are overcome. The multi-color fluorescent probe provided by the invention can be used for monomolecular level target molecule recognition and tumor cell recognition, and has good biocompatibility, so that the multicolor fluorescent probe has a good biomedical application prospect.

This invention relates to a method for constructing complex nanostructure with DNA molecules. The method comprises: selecting a single-stranded DNA as a scaffold chain, horizontally folding the DNA to obtain targeted structure, designing several short single-stranded DNAs as staple chains according to the folded scaffold chain, mixing the staple chains and the scaffold chain in solution, annealing, and self-assembling to obtain the target structure. This invention also discloses a method for metallization of DNA nanostructure with electronic device shape in the solution, and transferring it into air to obtain nanoscale electronic device. The method has such advantages as easy operation, and can construct symmetric or asymmetric highly complex DNA nanostructure that can be used in electronic industry.

The invention discloses a telomerase activity detecting method based on fluorescence resonance energy transfer (FRET). The telomerase activity detecting method comprises the following steps that firstly, fluorescence-modified Flare DNA is designed; then single-stranded DNA S1, single-stranded DNA S2, single-stranded DNA S3 and single-stranded DNA S4 are utilized to construct a DNA tetrahedral structure; then a DNA tetrahedron and the Flare DNA are hybridized, and thus a fluorescent DNA nano-probe is obtained; and the fluorescent DNA nano-probe and telomerase are mixed for reaction, and thus afluorescence spectrum of a mixture is obtained. The designed fluorescent probe based on FRET can provide a precise detection result, false positive signals are avoided, and the influence of system fluctuation in bioimaging is minimized; and on the other hand, a three-dimensional (3D) DNA nanostructure has excellent biocompatibility and nanoscale controllability and can enter cells through a rapidendocytic pathway, the basic integrity and stability of the cells are kept, and the 3D DNA nanostructure can be applied to biosensing and bioimaging after being reasonably assembled.

The invention provides a DNA nanostructure-modified microfluidic chip for optical biosensing and preparation and application of the DNA nanostructure-modified microfluidic chip. A system includes a microfluidic channel structure and a (hybridization chain reaction) HCR structure connected with an Aptamer. The microfluidic channel structure includes an upper layer and a lower layer, wherein the upper layer is a PDMS material plate, the lower layer is a microarray substrate, a reaction cavity is formed in the PDMS material plate, and the surface of the microarray substrate is modified with a DNAtetrahedron. The DNA tetrahedron is formed by four nucleotide single chains of A, B, C and D, wherein the A chain can be complementarily connected with a H2 chain base in the HCR structure in a paired mode, and the HCR structure includes an initiation chain I and a stem loop, namely, a H1 chain and a H2 chain, the 5' ends of the H1 chain and the H2 chain are modified with fluorescent groups, andthe initiation chain I is connected with the Aptamer. By adopting the system, the purpose of capturing circulating tumor cells efficiently is achieved.

The invention relates to a preparation method of a DNA nanorobot drug-carrying system. The preparation method comprises connecting at least one single-chain DNA with a hydrophobic drug molecule through a covalent bond to form a covalent connection product; adding the covalent connection product and residual single-chain DNAs into a first buffer solution containing magnesium ions, allowing to reactto assemble a complex of DNA nanostructure and hydrophobic drug molecule, allowing the residual single-chain DNAs and the single-chain DNA of the covalent connection product to form a DNA nanostructure having a lock through self-assembly, with the hydrophobic drug molecule locked inside the DNA nanostructure; providing a key, and allowing the key to cooperate with the lock to expose the hydrophobic drug molecule from the nanostructure, so that the DNA nanorobot drug-carrying system is provided. The invention also provides a DNA nanorobot drug-carrying system acquired via the preparation method. The DNA nanorobot drug-carrying system is suitable for targeted delivery and controlled release of drug molecules in live cells and has a good application prospect in the intelligent diagnosis andtreatment of major diseases.

The present invention relates to contrast medium composition and a method of bio imagination using the same. The contrast medium composition of the present invention includes a biomolecule, DNA nanostructure, as an active ingredient, is fundamentally non-cytotoxic and non-immunogenic and is not likely to induce safety problems that may be observed in other organic or inorganic contrast medium composition. In addition, the contrast medium composition of the present invention not only facilitates diagnosis of disease through sufficient contrast enhancement effect by showing excellent cellular uptake and intracellular stability and can visualize even SLNs which is difficult to be visualized traditionally, so can judge metastasis of cancer easily and apply lower invasive treatment.

Provided are DNA-coated nanoparticles (DNA-NPS), superparamagnetic nanoparticles (DNA-SPNs), and superparamagnetic iron oxide nanoparticles (DNA-SPIONs) as efficient imaging agents for targeting and imaging atherosclerotic lesions and treating atherosclerotic disease. The DNA-NS, DNA-SPNs, and DNA-SPIONs can enter macrophage cells via the Class A scavenger receptor (SR-A)-mediated pathways and can be used to specifically target atheroscleortic plaques.

The invention discloses a method for assisting in sorting lipidosome by utilizing a single-stranded DNA nanostructure. The method comprises the following steps of connecting a cholesterol-modified single-stranded DNA nanostructure with lipidosome to form a lipidosome complex, centrifugally separating out different components through iodixanol gradient density, and finally, obtaining a lipidosome library with uniform size in different components. Besides, the invention also provides the liposome complex, and the liposome complex can be used for effectively sorting liposomes with different sizes. An ssDNs auxiliary sorting technology easily produces the lipidosome with the average diameter of about 40-140nm, so that an attractive platform is provided for systematically exploring the size andthe shape of the lipidosome coated by ssDNs and related to absorption of the lipidosome by living cells.

The invention discloses an electrochemical sensor for detecting microRNA-21, a preparation method and application thereof. The method firstly anchors a DNA tandem with a biotin at the 5' end to the surface of an electrode, the DNA tandem is used as a main structure, and a G-rich quadruplex line is assembled by specific recognition of streptavidin-biotin as a branching structure; G tetra-chain monomer and G-quad-chain line pi-pi are stacked, self-assembly is conducted to form multi-branched DNA nanostructure, and the obtained DNA nano-assembly can be tightly combined with hemin to generate an oxidation reduction signal for electrochemical detection of miRNA-21. The method has good miRNA-21 detection sensitivity, has excellent specificity, can distinguish the single nucleotide mutation of the target nucleic acid analyte from the completely matched target RNA, analyzes an actual biological sample, and is a universal DNA nanometer biosensor platform.

The invention provides a target micro RNA induced-based branched DNA nanostructure and develops a simple and ultra-sensitive micro RNA detection method based on a target micro RNA induced branched DNAnanostructure. Short DNA single-stranded tails on the two sides of the double-stranded body can use hairpin DNA4 and hairpin DNA5 to start second-stage HCR amplification; a plurality of long double-stranded bodies are generated on the two sides of the formed long double-helix DNA, so that the formed branched chain DNA nano structure can carry a large amount of methyl blue, an electrochemical signal can be effectively enhanced, and a low detection limit is realized. More importantly, the strategy provides simple operation, good reliability and ultrahigh sensitivity. The method has been successfully applied to human serum samples, and shows satisfactory results and hopeful future. Importantly, the one-stop method can greatly reduce operation steps and avoid system errors caused by a plurality of operation steps.

The present invention provides methods and devices for specific detection of nucleic acids using an integrated circuit of two independent enzyme-DNA nanostructures—an easily adjustable recognition element and a sensitive universal signaling element—to decouple target recognition and visual signal amplification. The recognition element comprises a DNA polymerase enzyme, a DNA polymerase enzyme-specific DNA aptamer and an inverter oligonucleotide. In the presence of a target nucleic acid, the inverter oligonucleotide binds to the target nucleic acid and releases the DNA polymerase enzyme from inhibition by the DNA aptamer. The activated DNA polymerase enzyme is then contacted with a signaling nanostructure comprising a self-priming portion responsive to the DNA polymerase enzyme, in the presence of labelled dNTPs and signal development reagents, wherein the activated DNA polymerase enzyme would add the labelled dNTPs to the self-priming portion, followed by the binding of the signal development reagents to the labelled dNTPs.

The invention discloses a preparation method and application of a pMHC polymer based on a DNA nanotechnology. According to the invention, the DNA nanostructure is used as a support to connect different numbers of pMHCs, the number, position and direction of the pMHCs are controlled, and an atomic force microscope is used to clearly observe that the different numbers of pMHCs are captured and displayed on the DNA nanostructure. The DNA-pMHC is used for detecting the antigen-specific T cells, and due to the unidirectional multivalence effect mediated by the single orientation of the pMHC on the DNA nanostructure, the sensitivity of a DNA-pMHC multimer with the number of pMHC ranging from 3 to 12 is 1.9-4.3 times that of a pMHC tetramer when the antigen-specific T cells are detected is 1.9-4.3 times that of the DNA-pMHC multimer with the number of pMHC ranging from 3 to 12. The pMHC polymer based on the DNA nanotechnology has wide application prospects in analysis of antigen-specific T cells, and a powerful tool is provided for exploring the spatial biological effect of accurate protein arrangement under the nanoscale.

The invention discloses a target positioning and quantitative detection method based on DNA spherical nanostructure imaging. The target quantitative detection method relates to signal amplification detection, in particular to high-sensitivity detection of a low-abundance target in a sample; the multiple detection and multiple numbers of the target break through the limitation that a common fluorescence microscope can only detect 3-5 targets at the same time. The key content of the method relates to a case that a target specific detection object, such as an antibody, is connected with a single-chain oligonucleotide tag, then the single-chain oligonucleotide tag is amplified by using DNA loop-mediated rolling circle amplification, and the amplified nucleic acid can spontaneously form a spherical DNA nanostructure under the action of intramolecular hybridization; by designing a ring forming probe sequence, the spherical DNA nanostructure formed by a rolling circle amplification product can be hybridized with a fluorescently-labeled specific nucleic acid probe, so that the spherical DNA nanostructure shows a bright spot under a fluorescence microscope; and by positioning and counting the bright spot, positioning and digital quantitative detection of a to-be-detected target are implemented.

The invention discloses a multivalent aptamer functionalized DNA nanostructure probe as well as a preparation method and application thereof, one side of the DNA nanostructure of the probe is provided with a plurality of DNA aptamers, and the DNA aptamers can be specifically combined with a circulating tumor cell membrane surface protein receptor; a plurality of biotin sites are arranged on the other side of the substrate and can be combined with streptavidin modified magnetic particles; the probe is synthesized by six DNA single chains, namely S1, S2, N1, N2, N3 and SYL3C, and DNA sequences of the S1, the S2, the N1, the N2, the N3 and the SYL3C are respectively shown as SEQ ID NO.1-6. The probe disclosed by the invention can realize target cell recognition based on different expression levels of biomarkers on the surface of a cell membrane, the probe disclosed by the invention is simple to synthesize, high in CTCs capturing efficiency and easy to operate, and meanwhile, the enriched CTCs can be released through DNA hydrolase, so that the probe has potential significance on pathological diagnosis and other subsequent researches of the CTCs.