Micro-/nanomotors as platforms for gas therapy

Active delivery of therapeutic gases for disease intervention is an appealing but challenging task that requires breakthroughs in nanomaterial-based delivery systems. Micro-/nanomotors (MNMs) capable of efficiently converting diverse forms of energy into mechanical motion have inspired innovations in the gas delivery and therapy domains, offering an alternative possibility to address the challenges of targeted delivery and controlled gas release during therapy. This review thus comprehensively summarizes recent advances in employing MNMs as mobile platforms for precise gas delivery and therapy. The review begins with an introduction of the physiological functions of diverse therapeutic gases, including NO, H₂S, CO, O₂, and H₂. Then various proof-of-concept designs of artificial MNMs that can efficient propulsion in complex biological environments and intelligently release these gases in response to intrinsic or extrinsic stimuli are discussed. Particular emphasis has been placed on their potential in microenvironment modulation for disease treatment, aiming to demonstrate the distinct superiority of MNMs in this area. In addition, the key challenges and limitations of current MNMs utilized for gas therapy are addressed. It is believed that in the near future, MNMs will become sophisticated delivery platforms for facilitating gas therapy.