A DNAzyme-amplified DNA circuit for highly accurate microRNA detection and intracellular imaging

Abstract

A rationally and modularly engineered CHA-HCR-DNAzyme circuit was constructed for amplified biosensing and bioimaging with high performance.

A Smart, Autocatalytic, DNAzyme Biocircuit for in Vivo, Amplified, MicroRNA Imaging

“…Besides the efficient signal amplification, the delivery of nucleic-acid probes and an adequate intracellular supply of DNAzyme cofactors are also prerequisites for guaranteeing the DNAzyme-mediated intracellular imaging.I no ur previous CHA-HCR-DNAzyme system, [19] ac ommercial trans-fection agent (lipofectamine 3000) was utilized to achieve the efficient delivery of DNAzyme probes into living cells without supplying indispensable DNAzyme cofactors,r esulting in lower catalytic activity of DNAzyme for intracellular bioimaging.D ue to their good biocompatibility and facile synthesis,n anomaterials have emerged as attractive candidates for delivering various payloads into cells. [20] The extensively utilized DNAzyme relies on Mg 2+ ions,w hose intracellular concentration (0.5 mm) [17] is far below its minimal demand (5 mm) [16] for sustaining efficient DNAzyme biocatalysis.Thus various metal [21] and metallic oxides [22] have been introduced, as endogenous stimuli-responsive nanocarriers,t os upply DNAzyme cofactors.…”

“…[17] Forpromoting the signal amplification of DNAzymes,e fforts have been devoted to its efficient integration with other nonenzymatic amplification approaches,including HCR or CHA systems. [18] Moreover,w eh ave recently reported an intracellular miR-NA-imaging system based on ac oncatenated CHA-HCR-DNAzyme circuit, [19] in which the final DNAzyme layer is utilized merely as af inal transduction element. Yett he amplification capacity of the concatenated system is limited since the DNAzyme is unable to feedback into the previous CHA or HCR system, resulting in inefficient signal amplification.…”

Homogeneous and Universal Detection of Various Targets with a Dual‐Step Transduced Toehold Switch Sensor

“…Here our focus was mainly on demonstrating the general and powerful function of dual‐step transduction, so ultrahigh sensitivity was not laboriously pursued. Actually, this can easily be improved through many kinds of enzymatic or nonenzymatic reactions, as we and others have demonstrated …”

Targeted and direct intracellular delivery of native DNAzymes enables highly specific gene silencing

“…[14][15][16][17] The hydrophobic nature of cell membranes prevents the highly hydrophilic DNAzymes from crossing the membranes to enter cells. Efforts using cationic molecules, 18 nanomaterials [19][20][21][22][23][24] and liposomes 25,26 as carriers to ferry DNAzymes into cells have been extensively reported. Nevertheless, these carriers required complicated synthetic approaches and may show potential cytotoxicity to the cells.…”