Detection Of Tumor Markers Based On Nucleic Acid Nanomaterials In Living Cells

Nucleic acids have been actively developed for various delicate nanostructures due to their unparalleled programmability.The predictability of DNA interactions makes it possible to assemble 2D and 3D DNA structures with nanoscale dimensions.DNA is chemically inert in nature,and nanostructures based on unmodified DNA mostly lack functionality.However,functionality can be gained through chemical modification of DNA nanostructures,and the opportunities are limitless.In particular,framework nucleic acids with customizable functions and precise addressing capabilities have broad prospects in biomedical applications.The main research contents of this article are as follows:1.Utilizing the programmability of DNA,a star DNA nanoprobe capable of specifically recognizing MUC-1 protein and simultaneously detecting Survivin mRNA and TK1 mRNA was constructed.DNA nanostars have DNA strands complementary to Survivin mRNA and TK1 mRNA bases,respectively,which bind to Survivin mRNA and TK1 mRNA to separate the fluorophores that were originally quenched due to proximity to each other to separate cyanine 3(Cy3)and cyanine 5(Cy5)fluorescence recovery,the Survivin mRNA and TK1 mRNA were detected by the change of the fluorescence signal,and the target was sensitively detected.2.The DNA helix structure has a hydrophobic internal structure and a high degree of predictability,as well as an external structure with negative abnormalities,which is different from the protein structure.And the structure formed by DNA hybridization has dynamic properties.Designed and synthesized a DNA backbone icosahedron.The icosahedron contains a DNA sequence complementary to the base pair of Survivin mRNA and a DNA sequence complementary to the base pair of TK1 mRNA.Cy5 and cyanine 5.5(Cy5.5)modified in it Two kinds of fluorophores,two fluorophores undergo fluorescence resonance energy transfer process(FRET)due to their close proximity,and when Survivin mRNA and TK1 mRNA coexist,the DNA skeleton icosahedron is opened and will be coated on the DNA skeleton 2 The toxic protein gelonin in the decahedron is released into the cell,and at the same time,due to the opening of the icosahedron of the DNA skeleton,the distance between the two fluorophores increases,and FRET cannot occur.Through the change of the fluorescent signal,the ratio of Survivin mRNA in the cell is detected Purpose of TK1 mRNA.3.Combined with the biological characteristics of DNA functionalized hydrogels and the accuracy of the ratio detection method,a DNA crosslinked hydrogel was coated with silicon nanoparticles(SiNPs)to prepare a DNA crosslinked nanohydrogel.For fluorescence imaging determination of adenosine triphosphate(ATP)in cancer cells.When no ATP is present,FRET occurs,and FRET is in the "on" state;when ATP is present,fluorescence resonance energy transfer cannot be generated,and FRET is in the "off" state.Sensitive detection is achieved by measuring the proportional change in the fluorescence signal Purpose of intracellular ATP.Compared with traditional hydrogels,the size of this DNA crosslinked nanohydrogel is controllable,and it has good biocompatibility,biodegradability and colloidal stability.