Microrobots/micromotors in cancer therapeutics, advances and applications

Cancer remains one of the most challenging diseases to conquer due to its high mortality rate and the lack of effective diagnostic and therapeutic tools. Microrobot technology has brought revolutionary advancements to the field of tumor medicine. By leveraging its micro/nanoscale dimensions and precise propulsion and navigation capabilities, it has enhanced the accuracy and efficiency of cancer diagnosis and treatment. This review provides a detailed exploration of microrobots' motion from the perspectives of propulsion and navigation. It systematically summarizes its key applications in cancer therapy. Microrobots, which utilize gas, magnetic, light, or ultrasound-based propulsion mechanisms, and are combined with asymmetrical morphologies or biotargeted navigation, can traverse complex biological barriers such as the blood-brain barrier and mucus barrier. They enable precise delivery and controlled release of anticancer drugs. In the realm of diagnosis and imaging, microrobots, by carrying fluorescent probes or contrast agents, have improved the sensitivity of tumor detection and the resolution of deep tissue imaging. Furthermore, microrobots, when coordinated with photothermal therapy, sonodynamic therapy, or immunotherapy, have enhanced tumor eradication effects. They also activate immune responses to inhibit metastatic lesions. Finally, this review provides an outlook on the prospects of microrobots in tumor medicine, proposing potential collaborative pathways with emerging technologies. It highlights their vast potential in improving therapeutic efficacy and reducing side effects.