| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2018) | |
| Biomaterial Surfaces & Interfaces | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterial Interfaces Poster Session |
| Presenter: | Rachel Rosenzweig, University of California, Irvine |
| Authors: | R. Rosenzweig, University of California, Irvine V.K. Ly, University of California, Irvine K. Perinbam, University of California, Irvine A. Siryaporn, University of California, Irvine A.F. Yee, University of California, Irvine |
| Correspondent: | Click to Email |
Bacteria often populate environments where fluid flow is present such as the lungs of mammals, vasculatures of plants, industrial transportation fuel lines, and medical devices. Pseudomonas aeruginosa is an opportunistic biofilm forming bacterium that exhibits the ability to twitch upstream when surface attached. The upstream movement is facilitated by the retraction and extension of their type iv pili mechanosensor ATPase motors, pilT and pilU, when encountering shear stress. Such motility modalities of P. aeruginosa lead to bacterial surface adherence, colonization, and infectious biofilm formation. Here, upstream motility inhibition and surface detachment of P. aeruginosa were accomplished on polymeric biomaterial structures with arrays of nanopillared geometries.
Nanopillared surface structures were fabricated using thermal nanoimprint lithography on a synthetic polymer, poly(methyl methacrylate) (PMMA), commonly used in medical devices. The arrays of nanopillars range in periodicities from 200nm, 300nm, 500nm to 600 nm. Upstream motility direction, displacement, velocity, and detachment of wild-type P. aeruginosa expressing GFP were monitored in microfluidic flow channels with flat or nanopillared bottom surfaces and quantified using fluorescence microscopy. The cell motility inhibition and detachment under shear stress were observed to have a nanopillar surface area dependence most likely due to decrease in surface mechanosensing capabilities of the type iv pili. This bacteria-nanostructured surface interface phenomenon allows us to tailor surfaces with specific nanopillared geometries for structurally controlling cell motility and detachment under fluid flow. The disruption of surface attached biofilm forming bacterial upstream movement is crucial in preventing harmful infection from contaminated medical devices such as catheters and has broad application in industrial fuel line dependent transportation.