Magnetically Actuated Reactive Oxygen Species Scavenging Nano-Robots for Targeted Treatment

Magnetic micro/nanorobots (MagRobots) with unparalleled advantages, including remote mobility, high reconfigurability and programmability, lack of fuel requirement, and versatility, can be manipulated under a magnetic field, which has attracted considerable research attention in the biomedicine. Magnetic materials, as the key components of MagRobots, generate reactive oxygen species (ROS) in vivo to induce tissue/organ damage through Fenton/Fenton-like reactions, which may hinder the clinical application of MagRobots. Here, the biologically active Prussian blue is generated on the surfaces of MagRobots via an in situ reaction to obtain magnetically actuated ROS-scavenging nano-robots (ROSrobots). The generated Prussian blue blocks ROS production and endows the MagRobots with additional functionalities, markedly expanding their potential medical applications. Under the action of a magnetic field, the reconfigurable ROSrobots realize multimode transformation, locomotion, and manipulation in complex environments. Importantly, a simple control method is proposed to achieve movement in 3D geometries to allow the completion of tasks in a complex environment. Furthermore, the osteoarthritis (OA) rat model was employed for proof of concept. Notably, under the guidance of ultrasound imaging, ROSrobots can be accurately injected into the articular cavity to actively target the treatment of OA. This research may further promote the clinical application of MagRobots.