Suvai Gunasekaran with Christopher M. Jewell, Qi Lin, Helen E. Blackwell, and David M. Lynn

UW-Madison Departments of Chemical and Biological Engineering and Chemistry

Biofilms consist of populations of bacteria that work together to colonize and adhere to a variety of surfaces. Bacteria thrive within these biofilms because they surround themselves in an extracellular layer of natural polymer that protects the bacteria against external physical stresses, antibiotics, and the immune system. In many cases biofilm formation is undesirable, most notably with bacterial pathogens, and new ways to inhibit biofilm growth are of significant interest. For example, when biofilms form on biomedical devices implanted in the human body, serious bacterial infections can result and may even be fatal. Biofilm formation is under the control of cell-cell signaling processes called “quorum sensing.” The primary signal used by Gram-negative bacteria is N-acylated L-homoserine lactone (AHL). Using synthetic AHL compounds that can interfere with these naturally occurring chemical signals can potentially prevent biofilm growth by interrupting quorum sensing. We first studied methods to incorporate these synthetic compounds onto surfaces using polymers. We then investigated the release of these compounds based on variables including the type of compound and polymer, number of layers deposited, solution concentration, and coating procedure. The data from these experiments demonstrate that the amount of compound released increases with the number of layers deposited, as well as the loading concentration of the compound. With additional research we hope to explore promising ways to inhibit biofilm growth that might eventually prevent complications from bacterial infections resulting from biofilms growing on implanted biomedical devices.