title: Electrostatic nucleic acid nanoassembly enables hybridization chain reaction in living cells for ultrasensitive mRNA imaging.
abstract: Efficient approaches for intracellular delivery of nucleic acid reagents to achieve sensitive detection and regulation of gene and protein expressions are essential for chemistry and biology. We develop a novel electrostatic DNA nanoassembly that, for the first time, realizes hybridization chain reaction (HCR), a target-initiated alternating hybridization reaction between two hairpin probes, for signal amplification in living cells. The DNA nanoassembly has a designed structure with a core gold nanoparticle, a cationic peptide interlayer, and an electrostatically assembled outer layer of fluorophore-labeled hairpin DNA probes. It is shown to have high efficiency for cellular delivery of DNA probes via a unique endocytosis-independent mechanism that confers a significant advantage of overcoming endosomal entrapment. Moreover, electrostatic assembly of DNA probes enables target-initialized release of the probes from the nanoassembly via HCR. This intracellular HCR offers efficient signal amplification and enables ultrasensitive fluorescence activation imaging of mRNA expression with a picomolar detection limit. The results imply that the developed nanoassembly may provide an invaluable platform in low-abundance biomarker discovery and regulation for cell biology and theranostics.
authors.affiliation: State Key Laboratory of Chemeo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Chemeo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.
authors.forename: Gao-Qin
authors.initials: GQ
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Chemeo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Chemeo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D004247:DNA / Q000737:chemistry*; D015342:DNA Probes / Q000737:chemistry*; D006801:Humans; D051379:Mice; D057054:Molecular Imaging; D049329:Nanostructures / Q000737:chemistry*; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000032:analysis*; D055672:Static Electricity
chemical_list: D015342:DNA Probes; D012333:RNA, Messenger; D004247:DNA