Magnetically Guided Microrobots for Targeted Drug Delivery.

Conventional drug delivery routes, such as oral and injectable administration, often suffer from poor targeting, systemic side effects, and limited control over drug release. Magnetically guided microrobots have emerged as a promising solution by enabling minimally invasive navigation, precise localization, and controllable cargo delivery in complex biological environments. Recent advances in microfabrication, biomaterials, and magnetic actuation have led to diverse microrobot designs, including helical swimmers and biohybrid systems incorporating red blood cells, bacteria, algae, or exosomes. These microrobots can transport drugs, cells, or theranostic agents, with release triggered by magnetic, chemical, optical, or acoustic stimuli. In parallel, progress in imaging and tracking technologies, such as ultrasound, photoacoustic imaging, X-ray, and MRI, has enabled real-time guidance and monitoring in vivo. Despite encouraging proof-of-concept studies, several challenges hinder clinical translation. These include limited biocompatibility, reduced locomotion efficiency under physiological flow, insufficient release precision, and regulatory constraints. Future development requires safer and more robust materials, multimodal imaging strategies for accurate navigation, and scalable fabrication methods that meet medical standards. With continued integration of engineering and biomedical research, magnetically guided microrobots hold strong potential for targeted therapy, regenerative medicine, and minimally invasive treatment, representing a significant advance in precision drug delivery.