Programming Living Glue Systems to Perform Autonomous Mechanical Repairs

Summary Many biological materials endow organisms with the capacity for sophisticated mechanical operation. To date, recapitulating such dynamic mechanical processes with engineered living materials (ELMs) has remained elusive. Here, we engineer living glue systems to perform on-demand mechanical operations. By rationally combining diverse genetic circuits, we develop chemical- and light-regulated glue systems capable of accomplishing tasks, including the capture of microspheres from solution, to form living composite coatings and light-regulated spatially targeted damage repair. Moreover, we demonstrate a glue system for autonomous repair: upon sensing blood leaking from a purposely damaged microfluidic device, bacterial strains comprising this glue system localize to the damage site, communicate via a cell-cell communication network, and plug the leak with their amyloid glue components. Thus, beyond demonstrating how living glue systems can be programmed to implement mechanical operations, our study represents the first step toward smart ELMs for autonomous repairs in both industrial and medical settings.