Hydrogen‐Powered Microswimmers for Precise and Active Hydrogen Therapy Towards Acute Ischemic Stroke

Abstract Biodegradable microswimmers offer great potential for minimally invasive targeted therapy due to their tiny scale, multifunctionality, and versatility. However, most of the reported systems focused on the proof‐of‐concept on the in vitro level. Here, the successful fabrication of facile hydrogen‐powered microswimmers (HPMs) for precise and active therapy of acute ischemic stroke is demonstrated. The hydrogen (H 2 ) generated locally from the designed magnesium (Mg) microswimmer functions not only as a propellant for motion, but also as an active ingredient for reactive oxygen species (ROS) and inflammation scavenging. Due to the continuous detachment of the produced H 2 , the motion of the microswimmers results in active H 2 delivery that allows for enhanced extracellular and intracellular reducibility. With the help of a stereotaxic apparatus device, HPMs were injected precisely into the lateral ventricle of middle cerebral artery occlusion (MCAO) rats. By scavenging ROS and inflammation via active H 2 , MCAO rats exhibit significant decrease in infarct volume, improved spatial learning and memory capability with minimal adverse effects, demonstrating efficient efficacy on anti‐ischemic stroke. The as‐developed HPMs with excellent biocompatibility and ROS scavenging capability holds great promise for the treatment of acute ischemic stroke or other oxidative stress induced diseases in clinic in the near future.