Engineered oncolytic bacteria for malignant solid tumor treatment

Abstract Bacteria have been explored for their potential in fighting against cancer for decades. Due to their outstanding tumor‐targeting capacity and high biocompatibility, live bacteria can serve as microrobots delivering and producing anti‐tumor agents. In addition, live bacteria have intrinsic immune‐activating functions that aid in the generation of anti‐tumor immunity both systemically and locally in the tumor microenvironment. While bacteria‐based cancer therapy is still facing great challenges, progress in this platform combined with nanobiotechnologies has shown promise in terms of safety and effectiveness. Here, basic development strategies of bacteria‐based delivery systems armed with nanotechnologies, virulence attenuation, and genetic manipulation are summarized and the design of a spatiotemporal selectivity is particularly emphasized. In conclusion, the engineered bacteria platform has a high potentiality in the development of novel cancer therapeutics and holds prospects for future investigation and clinical use.