Ultrasound-Responsive Engineered Bacteria for Targeted Cancer Therapy: Strategies, Mechanisms, and Applications

In recent years, with the rapid advancement of synthetic biology and nanoscience, microbial therapy based on engineered bacteria has garnered renewed widespread attention and achieved remarkable research progress. Specifically, through biological and physicochemical methods, bacteria from diverse sources with unique characteristics are functionally modified and engineered to combine with conventional therapeutic approaches. This aims to overcome or mitigate the limitations of standard treatments in clinical applications. On this basis, the integration of exogenously responsive regulatory factors (e.g., ultrasound) with microbial therapy undoubtedly provides a more intelligent, precise, and promising therapeutic strategy for tumor treatment. In this review, we summarize the core methods for direct modification, mechanisms of action, and main application strategies of engineered bacteria in tumor therapy. Meanwhile, we focus on elaborating the forms and interaction mechanisms of combining ultrasound with engineered bacteria, and discuss in detail the latest research advances in their combined application for tumor therapy. A comprehensive understanding of their relationships and interaction mechanisms will provide theoretical support for the development of ultrasound-regulated bioactive molecules and ultrasound-responsive intelligent drug delivery systems, thereby further advancing the applications of ultrasound technology and microbial therapy in the biomedical field.