Coated Bacteria: Advanced Living Materials for Microbial Therapy

Living materials represent an emerging and innovative concept at the forefronts of materials science due to the distinctive living characteristics. Living organisms, such as microorganisms, plant cells, and mammalian cells, have been used as the major elements for the fabrication of living materials. Given the favorable features including reproductivity, genetic modifiability, adaptability, and cultivability, bacteria have received increasing attention for the development of engineered living materials. Particularly, owing to the inherent abilities to target and colonize specific in vivo sites, activate immune responses, and inhibit pathogens, bacteria play key roles in maintaining human health and have currently widely exploited as living materials for the preparation of therapeutic agents. However, caused by the innate immunogenicity, metabolic activity, and movability, the use of bacteria-based living materials for therapeutic applications often suffers from poor biosafety and insufficient bioavailability, inevitably resulting in low treatment efficacy. In order to address these challenges, extensive efforts have been invested in designing and engineering various advanced bacteria-based living materials to generate superior therapeutic agents by using genetic modification and surface decoration.