Recent progress of micro/nanomotors to overcome physiological barriers in the gastrointestinal tract

Oral administration is a convenient administration route for gastrointestinal disease therapy with good patient compliance. But the nonspecific distribution of the oral drugs may cause serious side effects. In recent years, oral drug delivery systems (ODDS) have been applied to deliver the drugs to the gastrointestinal disease sites with decreased side effects. However, the delivery efficiency of ODDS is tremendously limited by physiological barriers in the gastrointestinal sites, such as the long and complex gastrointestinal tract, mucus layer, and epithelial barrier. Micro/nanomotors (MNMs) are micro/nanoscale devices that transfer various energy sources into autonomous motion. The outstanding motion characteristics of MNMs inspired the development of targeted drug delivery, especially the oral drug delivery. However, a comprehensive review of oral MNMs for the gastrointestinal diseases therapy is still lacking. Herein, the physiological barriers of ODDS were comprehensively reviewed. Afterward, the applications of MNMs in ODDS for overcoming the physiological barriers in the past 5 years were highlighted. Finally, future perspectives and challenges of MNMs in ODDS are discussed as well. This review will provide inspiration and direction of MNMs for the therapy of gastrointestinal diseases, pushing forward the clinical application of MNMs in oral drug delivery.

Automated summary

Oral administration is a convenient way to treat gastrointestinal diseases with good patient compliance, but the nonspecific distribution of drugs can lead to serious side effects. To overcome this, oral drug delivery systems (ODDS) have been developed, but they are limited by physiological barriers in the gastrointestinal tract. Micro/nanomotors (MNMs) have shown potential in targeted drug delivery, and this review comprehensively discusses their applications in overcoming physiological barriers in ODDS for gastrointestinal diseases. This review provides inspiration and direction for MNMs in the therapy of gastrointestinal diseases and advances the clinical application of MNMs in oral drug delivery.