Molecular Transport of a Magnetic Nanoparticle Swarm Towards Thrombolytic Therapy

Due to miniature size, controllability, navigation and versatile capability, micro/nanorobots is appealing for minimally invasive procedures. In particular, blood clot as an unwanted biological object in vessel leads to severe diseases. Herein, we report a magnetite nanoparticle swarm (Fe3O4) that is capable of inducing hydrodynamic effect to capture tissue plasminogen activator (t-PA) in emergent vortices under the dynamic magnetic field. Once the swarm move to approach a site of a blood clot, the caged t-PA molecules are transported together with it across the interface for thrombolysis. In addition, the dynamic motion of each individual spinning nanorobot can assist the clot removal by exerting mechanical force to rub against the softened clot with loose fibrin fibers that is incompletely dissolved by chemical lysis of t-PA. Feasibility and performance of the swarm towards thrombolytic therapy are approved by in vitro experiments. The result reports that blood clot with 3-mm-diameter and 9-mm-length is completely removed in two hours, faster than the clinical procedure applying t-PA alone about 3 times. The contribution is extensible to apply for medical treatments ranged from simple tasks (e.g. detoxification) to complex tasks (e.g. tumor destroy).