Progress of Micro/Nanomotors for In Vivo Biomedical Applications

As a new-generation intelligent diagnostic and therapeutic platform, micro/nanomotors (MNMs) hold great promise for overcoming the limitations of conventional passive drug delivery systems, such as poor penetration across physiological barriers. By converting chemical, optical, acoustic, or magnetic energy into kinetic motion, MNMs enable actively propelled, targeted delivery, making them a promising emerging tool for precision medicine. This review provides a comprehensive overview of the progress in the propulsion mechanisms and motion control strategies of MNMs, emphasizing how to achieve controllable movement in vivo. The in vivo biological applications of MNMs are highlighted, including penetration of the blood-retinal barrier for ophthalmic therapies, crossing of the blood-brain barrier (BBB) for neurological interventions, targeted drug release to chronic inflammatory sites, intelligent gastrointestinal drug administration, precision thrombosis in cardiovascular diseases, and the advancement of multimodal cancer therapies. The key challenges and outlooks of MNMs for clinical translation are discussed.