Microrobots for Targeted Delivery and Therapy in Digestive System

Untethered miniature robots enable targeted delivery and therapy deep inside the gastrointestinal tract in a minimally invasive manner. By combining actuation systems and imaging tools, significant progress has been made toward the development of functional microrobots. These robots can be actuated by external fields and fuels while featuring real-time tracking feedback toward certain regions and can perform the therapeutic process by rational exertion of the local environment of the gastrointestinal tract (e.g., pH, enzyme). Compared with conventional surgical tools, such as endoscopic devices and catheters, miniature robots feature minimally invasive diagnosis and treatment, multifunctionality, high safety and adaptivity, embodied intelligence, and easy access to tortuous and narrow lumens. In addition, the active motion of microrobots enhances local penetration and retention of drugs in tissues compared to common passive oral drug delivery. Based on the dissimilar microenvironments in the various sections of the gastrointestinal tract, this review introduces the advances of miniature robots for minimally invasive targeted delivery and therapy of diseases along the gastrointestinal tract. The imaging modalities for the tracking and their application scenarios are also discussed. We finally evaluate the challenges and barriers that retard their applications and hint on future research directions in this field.

Automated summary

Untethered miniature robots have shown great potential for targeted delivery and therapy inside the gastrointestinal tract. They can be controlled externally and utilize the local environment for therapeutic purposes. Compared to conventional surgical tools, these robots offer minimally invasive diagnosis and treatment, multifunctionality, and easy access to narrow lumens. The active motion of microrobots also improves drug penetration and retention in tissues. This review discusses the advances in miniature robots for minimally invasive targeted delivery and therapy, including the imaging modalities used for tracking, and highlights the challenges and future research directions in this field.