In-situ biofabrication of stratified biofilm mimics for direct observation of bacterial signaling

Cell-cell signaling is essential to biological functions. Communications between individual cells, clusters of cells and populations exist in complex networks that, in sum, guide behavior. However, there are few experimental approaches that enable high content interrogation of individual and multicellular behaviors at length and time scales commensurate with the signal molecules and cells themselves. Biofabrication in microfluidics represents one such approach that enables in-situ organization of living cells in microenvironments with spatiotemporal control and programmability. We construct bacterial biofilm mimics that offer detailed understanding and subsequent control of population-based bacterial signaling. Our approach reveals signaling patterns among bacterial cells within a single biofilm as well as behaviors that are coordinated between two communicating biofilms. Our biofabrication strategy is versatile for cell-cell interaction studies and small molecule drug discovery.