Highly Integrated, Biostable, and Self-Powered DNA Motor Enabling Autonomous Operation in Living Bodies.

An ultimate goal of synthetic DNA motor studies is to mimic natural protein motors in biological systems. Here, we rationally designed a highly integrated and biostable DNA motor system with high potential for living body operation, through simple assembly of a Mn2+-dependent DNAzyme-powered DNA motor with a degradable MnO2 nanosheet. The motor system shows outstanding high integration and improved biostability. High integration confers the motor system with the ability to deliver all the core components to the target sites as a whole, thus, enabling precise control of the spatiotemporal distribution of these components and achieving high local concentrations. At the target sites, reduction of the MnO2 nanosheet by intracellular glutathione (GSH) not only releases the DNA motor, which can then be initiated by the intracellular target, but also produces Mn2+ in situ to power the autonomous and progressive operation of the DNA motor. Interestingly, the resultant consumption of GSH in turn protects the DNA motor from destruction by physiological GSH, thus, conferring our motor system with improved biostability, reduced false-positive outputs, and consequently, an increased potential to be applied in a living body. As a proof of concept, the highly integrated DNA motor system was demonstrated to work well for amplified imaging detection of survivin mRNA (mRNA), an important tumor biomarker, in both living cancer cells and living tumor-bearing mice. This work reveals concepts and strategies promoting synthetic DNA motor applications in biological systems.