The significant potential for autonomous movement and adaptable modification has made micro/nanomotors a major focus of research and application in biomedicine. However, current designs for micro/nanomotors face several unresolved issues, including improving propulsion methods, precise navigation control, expanding application ranges, ensuring biological safety, and achieving multifunctionality. This review provides a comprehensive overview of recent progress in the application of micro/nanomotors in biomedicine, focusing on propulsion mechanisms, targeting strategies, structural design, and practical applications.

In this review, we summarize the latest advancements in the construction and application of Micro/nanomotors (MNMs) and categorize these developments. MNMs have been utilized in various biomedical fields, with their active motility and targeting capabilities revolutionizing in vivo delivery technologies. This transformation has significantly enhanced delivery efficiency and reduced off-target effects. Various therapeutic approaches, such as physical therapy, biological therapy, chemical drug therapy, and immunotherapy, are continuously being developed and implemented. Furthermore, biosensing technologies derived from MNMs have enhanced detection sensitivity and quality. The potential for removing toxic substances from biological systems may also develop in the future. In addition, researchers are integrating MNMs as probes and imaging agents into traditional medical devices, which demonstrates their vast potential. We anticipate the development of multifunctional MNMs tailored to specific application needs, with various propulsion modes being employed.

This review begins by providing an overview of the three major elements of MNMS construction: propulsion, targeting, and structure. We point the current issues associated with these elements and examine the attempted solutions. Our discourse also analyzes the current status and summarizes the development trends in various fields to provide researchers with valuable insights. Additionally, this review outlines the primary applications of MNMs in the biomedical field, discusses the development trends and establishes directions for the advancement of multimode propulsion and multifunctional integration platforms.

MNMs, as a medical device, face complex ethical, moral, and legal issues. The impact of the fabrication and application of MNMs on biological systems lacks real-time and effective regulatory measures, which results in widespread regulatory obstacles. Furthermore, the effects of MNMs upon entering biological organisms have not been thoroughly investigated. This lack makes their long-term safety unconvincing. Regulatory authorities and researchers should enhance the technical and ethical oversight of MNMs, refine existing laws, and conduct further research throughout the entire application process to ensure their transition into clinical practice.