Magnetically Powered Microrobotic Swarm for Integrated Mechanical/Photothermal/Photodynamic Thrombolysis

Abstract

Current thrombolytic drugs exhibit suboptimal therapeutic outcomes and potential bleeding risks due to their limited circulation time, inadequate thrombus penetration, and off‐target biodistribution. Herein, a photosensitizer‐loaded, red cell membrane‐encapsuled multiple magnetic nanoparticles aggregate is successfully developed for integrated mechanical/photothermal/photodynamic thrombolysis. Red cell membrane coating endows magnetic particles with prolonged blood circulation and superior biocompatibility. Under a preset rotating magnetic field (RMF), the aggregate with asymmetric magnetic distribution initiates rolling motion toward the blood clot interface, and because of magnetic dipole‐dipole interactions, the aggregate tends to self‐assemble into longer, flexible chain‐like microrobotic swarm with powerful mechanical stir forces, thereby facilitating thrombus penetration and mechanical thrombolysis. Moreover, precise magnetic control enables targeted photosensitizer accumulation, allowing effective conversion of near‐infrared (NIR) light into heat and reactive oxygen species (ROS) for thrombus phototherapy. In thrombolysis assays, the weight of thrombi is massively reduced by ≈90%. The work presents a safer and more promising combination of magnetic microrobotic technology and phototherapy for multi‐modality thrombolysis.