284334 In-Situ Biofabrication of Spatially Programmed Biofilm Mimics for Direct Observation of Bacterial Signaling

Thursday, November 1, 2012: 1:45 PM
Westmoreland Central (Westin )
Xiaolong Luo1, Chen-Yu Tsao2, Hsuan-Chen Wu2, Gary W. Rubloff3 and William E. Bentley1,2, (1)Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD, (2)Fischell Department of Bioengineering, University of Maryland, College Park, MD, (3)Department of Materials Science and Engineering, University of Maryland, College Park, MD

Within bacterial communities, signaling molecules interspersed among individual cells cue population-scale behavior, including pathogenesis.  While denoted “quorum sensing” (QS) because the multicellular phenotype is often mapped onto and coincides with high cell number, the molecular basis for multicellularity remains somewhat obscure.  In part, this is because 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.  Here, we have developed such an approach by “biofabricating” bacterial biofilm mimics with polysaccharides within microfluidic channels that enable detailed understanding and subsequent control of population-based QS behaviors in a manner decoupled from cell number.  The biofabrication takes advantage of two stimuli-responsive polysaccharides, chitosan (a chitin derivative from exoskeleton of crustaceans with pH-dependent film forming properties) and alginate (an extract of cell wall of brown algae that cross-links as “eggbox” structure in presence of divalent cations such as Ca2+).  We demonstrate programmability via pH and chemical gradients generated in situ using fluidics.  This methodology preserves independent fluidic access for each layer.  Cell-cell signaling was demonstrated among and between bacterial populations with gradient response, which indicates that we can actively control the communication between cell populations with external flow dynamics.  We envision versatile use of this biofabrication strategy for cell-cell interaction studies and small molecule drug discovery.

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See more of this Session: Biomimetic Materials
See more of this Group/Topical: Materials Engineering and Sciences Division