The UH Cullen College of Engineering has won its fifth National Science Foundation CAREER Award of 2012. Assistant Professor of Chemical and Biomolecular Engineering Jacinta Conrad received the five-year, $400,000 grant to develop surfaces that limit bacterial motility, or movement.
How bacteria move, Conrad said, influences the formation of biofilms, colonies of bacteria that are protected by an extracellular matrix made of proteins. Once formed, biofilms are extremely difficult to remove and often extremely problematic. Biofilms that form in oil and water pipelines foul the liquids flowing through them. In hospitals, they are implicated in up to 80 percent of all non-specific infections, while they are cited as a significant source of drag on marine vessels.
Over the past 18 months, Conrad and her collaborators have published two articles revealing new methods of bacteria motility. A piece in the October 8, 2010 issue of Science shows bacteria using hairlike appendages called pili to pull themselves upright and “walk,” allowing them to sense and cover large areas before forming biofilms. In June of 2011, the researchers published an article in the Proceedings of the National Academy of Sciences showing that bacteria use pili to quickly “slingshot” themselves into a new orientation.
Conrad plans to use this newfound understanding of bacteria motility to design surfaces that can inhibit biofilm formation and change the shapes these biofilms take.
“People have spent a lot of time looking at how to make antifouling surfaces,” she said. “What we think we can do is use our understanding of fundamental mechanisms of bacteria motility to determine the specific properties that we think will keep pili from sticking to a surface.”
Using polymer thin films layered on a glass substrate, then, she will work to prevent pili from attaching to a surface by altering its chemistry, its elasticity (or hardness) and its topography (or texture).
One of the advantages to this approach, Conrad noted, is that it would be inexpensive compared to other antifouling technologies currently being developed, making it ideal for covering large spaces like the inside of pipelines or the hulls of marine vessels.
“We’re looking for large area strategies, coatings that you could just paint on, for example. You’re not going to cover a whole wall with an engineered biomolecule because that would be too expensive. But maybe you’ll apply a coating that inhibits biofilm formation and makes it easy to scrape it off,” she said.
NSF CAREER Awards are among the most prestigious grants in the STEM fields (science, technology, engineering and mathematics), and are among the few awards factored into the official Top American Research University rankings. These grants are given to outstanding junior-level faculty members to help them launch long-term, successful research careers. In addition to Conrad, the college’s 2012 CAREER award winners to date are Jiming Bao, Debora Rodrigues, Wei-Chuan Shih and Gila Stein.