Cellular and In Vivo Fate of DNA Nanostructures.

DNA nanotechnology is a cutting-edge discipline that exploits the principle of complementary base pairing to direct the self-assembly of precisely defined nanostructures. This review systematically surveys the fundamental concepts, assembly strategies, and biomedical applications of DNA nanostructures, with a particular focus on their cellular and in vivo fate and the methodologies used to investigate these processes. We categorize representative DNA architectures by their assembly strategies into three major classes and discuss the design principles and distinctive characteristics of each. A comprehensive analysis is provided of the critical determinants governing their biological behavior, encompassing intrinsic structural parameters (size, morphology, and surface modifications) and extrinsic physiological factors (enzymatic activity, pH, and temperature). We further review the principal techniques for monitoring their cellular and in vivo dynamics-including fluorescence imaging, radiolabeling, and magnetic resonance imaging (MRI). In vivo processes-absorption, biodistribution, cellular uptake, metabolic clearance, and immunogenicity-are examined in depth. Finally, we delineate the key translational barriers and outline emerging opportunities in intelligent responsive design, immunomodulation, and theranostic integration. This review provides a conceptual framework for navigating the critical design trade-offs inherent in engineering DNA nanostructures for in vivo application and offers forward-looking perspectives for the development of DNA-based nanocarriers.