Photosensitizers in Motion: Micro- and Nanomotor-Assisted Photodynamic Therapy

Photodynamic therapy (PDT) is a clinically relevant and minimally invasive strategy for treating diseases associated with uncontrolled tissue growth, including nonmelanoma skin cancers and microbial infections. Its spatiotemporal selectivity minimizes damage to healthy tissues and limits the emergence of therapeutic resistance, while its versatility enables integration with complementary therapeutic approaches. One emerging direction is the combination of PDT with artificial self-propelled micro- and nanomotors (MNMs). Active MNM motion enhances photosensitizer (PS) transport and localization, while oxygen-generating or oxygen-supplying MNM platforms can partially mitigate hypoxia-related limitations of PDT. This Review provides a comprehensive overview of recent advances in MNM-assisted PDT, highlighting commonly used PS molecules and strategies for their integration into MNMs to couple photodynamic activity with autonomous propulsion. It examines representative in vitro and in vivo studies, identifies critical performance parameters and current challenges, and explores future opportunities for the rational design of next-generation self-propelled phototherapeutic systems.