Dynamic DNA nanostructures in biomedicine: Beauty, utility and limits

DNA composite materials are at the forefront, especially for biomedical science, as they can increase the efficacy and safety of current therapies and drug delivery systems. The specificity and predictability of the Watson-Crick base pairing make DNA an excellent building material for the production of programmable and multifunctional objects. In addition, the principle of nucleic acid hybridization can be applied to realize mobile nanostructures, such as those reflected in DNA walkers that sort and collect cargo on DNA tracks, DNA robots performing tasks within living cells and/or DNA tweezers as ultra-sensitive biosensors. In this review, we present the diversity of dynamic DNA nanostructures functionalized with different biomolecules/functional units, imaging smart biomaterials capable of sensing, interacting, delivery and performing complex tasks within living cells/organisms.