ROS-Triggered Hemispheroid Adhesive Micromotors for Inflammatory Bowel Disease Therapy.

The use of micromotors-based delivery systems for inflammatory bowel disease (IBD) treatment has recently gained considerable interest. The current research primarily focuses on how to design micromotors with more elaborate geometries and actuation mechanisms to improve IBD therapeutic effects. Herein, a novel type of reactive oxygen species (ROS)-responsive hemispheroid adhesive micromotors (HMPs) as efficient delivery systems is developed to treat IBD. Such HMPs are fabricated through microfluidic electrospray technique, with a platinum (Pt) layer and dopamine (DOPA) coating layer covered on its top surface and baseplate, respectively. The Pt on HMPs' top surface can produce oxygen from hydrogen peroxide, thereby providing a propulsion force for them to move spontaneously upon exposure to ROS environment. Moreover, the DOPA layer on the baseplate contributed to the outstanding adhesive capacity to tissues. Therefore, by incorporating anti-inflammatory dexamethasone (DXM) into HMPs, the resultant micromotor systems are imparted with superior antioxidant and anti-inflammatory capacities, which also exhibits desirable therapeutic effect upon treating IBD by alleviating inflammatory response, restoring epithelial barrier functions, and mitigating IBD-associated symptoms. The treatment mechanism of DXM-loaded HMPs mainly involves alleviating oxidative stress, reducing proinflammatory cytokines secretion, and protecting intestinal barrier. Collectively, these results illustrate HMPs-based micromotor systems are valuable for gastrointestinal disease treatment.