A Microfluidic Platform for Optical Monitoring of Bacterial Biofilms

Abstract

Bacterial biofilms are pathogenic matrices which characterize a large number of infections in humans and are often formed through bacterial intercellular molecular signaling. A microfluidic platform for the evaluation of bacterial biofilms based on optical density was fabricated and tested. The platform was used to non-invasively observe the formation of Escherichia coli biofilms. These methods were corroborated by measurement of biofilm optical thickness. The dependence of biofilm optical density on bacterial communication was evaluated. After 60 hours of growth at 10 μL/hr, wild-type biofilms were approximately 100% more thick and 160% more optically dense than biofilms formed by non-communicating bacteria. The thicknesses of the detected biofilms are comparable to those found in literature for both in vitro and in vivo biofilms seen in microbial infections. The platform was also used to observe the effect of flow parameters on biofilm adhesion; results indicate bacterial communication in biofilm formation is necessary for adherent biofilms. The presented platform will be used in characterization of biofilm formation and response in drug discovery applications.