Photothermal Amplification via Nanorobotic Swarming Dynamics

Photothermal therapy represents a promising therapeutic approach due to its non-invasiveness and spatiotemporal controllability. However, conventional nanoparticle-based systems are limited by low conversion efficiency, quick heat dissipation, and the high dosages required for sufficient therapeutic hyperthermia. Although micro/nanorobotic platforms improve targeting, they still face challenges in achieving adequate localized heat safely, often requiring high material concentrations that risk vascular complications. To address these limitations, this work introduces a strategy leveraging magnetically regulated swarming dynamics to amplify photothermal conversion. With designed magnetic actuation, building blocks are organized into the reconfigurable microswarm, achieving localized densification that minimizes heat dissipation and achieves photothermal amplification under near-infrared (NIR) light. Compared with the dispersive state, the microswarm exhibits a 23 ̊C enhancement owing to its boosted photothermal conversion efficiency and great thermal stability across variable scales, effectively overcoming rapid heat dissipation in dynamic environments. Besides, magnetically controlled reconfiguration allows tunable heating areas, balancing spatial coverage and therapeutic intensity. Compared with dispersive systems, a 7-fold improvement in the cancer cell-killing efficiency of the microswarm can be achieved via photothermal amplification. This work establishes a photothermal amplification strategy to overcome limitations of passive diffusion and dosage dependence, pioneering a versatile nanorobotic platform for precision photothermal-based treatment.