Swallowable micro-/nanorobots for disease treatment

Micro-/nanorobots (MNRs), miniature devices designed to execute precise medical function, represent an emerging nanotechnology platform for therapeutic applications. By transforming diverse forms of energy into mechanical motion, MNRs can actively navigate and overcome physiological barriers that have limited the efficacy of conventional nanomedicine delivery, thereby inspiring novel therapeutic paradigms. Oral administration, owing to its high patient compliance, is widely applied for treating various diseases. To accelerate the clinical translation of MNR systems, this review comprehensively surveys recent advances in orally administrable MNRs-termed swallowable MNRs. This review begins with a summary of common clinical routes of drug delivery, discussing the characteristics and applicability of different clinical routes. Afterward, various physiological environments in the gastrointestinal tract that compromised the oral delivery efficacy are introduced. On the basis of a summary of fabrication materials and strategies, particular attention has been paid to reviewing swallowable MNRs for treating various diseases, including gastrointestinal disorders, diabetes mellitus and cancer. Finally, the challenges and prospects of swallowable MNRs are addressed, with the aim of inspiring innovative material-based solutions for disease management.