Unsynchronized Translational and Rotational Diffusion of Nanocargo on a Living Cell Membrane

摘要

Targeted drug and gene delivery with functional nanomate-rials has received considerable attention in cancer therapies and stem cell studies. Gold nanomaterials (especially gold nanorods (GNRs)) are widely utilized for the efficient and smart intracellular delivery of drugs and genes because of their high-loading and high-internalization efficiency, bio-compatibility, and controllable release. Understanding the translocation dynamics of these nanocargos in living cells at the single particle level would provide valuable information to rationally design their functionality and further modulate their intracellular delivery efficiency. To this end, several noninvasive optical imaging techniques have been developed, for example, conventional darkfield microscopy, photothermal imaging, and interferometric scattering detection. Nevertheless, these center-of-mass lateral localization methods cannot provide access to the orientational dynamics of nanocargos that would be a key parameter for revealing the fundamental mechanisms of vital biological processes, such as the interactions between the nanocargo and nearby biomol-ecules.