(65d) A New Antifouling Strategy with Active Surface Topography

A new antifouling
strategy with active surface topography

Huan Gu^{1, 2},
Sang Won Lee^1,2, Dacheng Ren^1,2,3,4*

¹Department of Biomedical and Chemical
Engineering, ²Syracuse Biomaterials Institute, ³Department
of Civil and Environmental Engineering, ⁴Department of Biology,
Syracuse University, Syracuse, NY 13244, United States

Bacteria
can attach and form multicellular structures, known as biofilms, on virtually
any abiotic or biotic surface. Due to the protection
of extracellular polymer substrates (EPS) and slow growth, biofilm cells
are up to 1,000 times more resistant to antimicrobials compared to their
planktonic counterparts. Biofilms related high-level drug tolerance causes
serious problems of persistent biocorrosion and biofouling in industry, as well
as chronic infections in humans. The significance of biofilm-associated problems has stimulated intensive efforts on developing materials and surface
modification techniques to prevent bacterial adhesion. However, the studies to
date are largely limited to static features, which can be overcome by microbes
over time and does not provide long-term prevention. To better control
biofilm formation, we engineered active
surface topographies that not only can effectively prevent initial bacterial
adhesion but also achieve on-demand removal of mature biofilms. In this
approach, rationally designed antifouling surface topographies are actuated by external stimuli with
programmable beating frequency and force to repel bacteria and disrupt mature
biofilms. In a proof-of-concept study, systematically designed micron-scale
poly(dimethylsiloxane) (PDMS) surface topographies filled with biocompatible superparamagnetic Fe₃O₄ nanoparticles were actuated with an external magnetic field (5 mT). The antifouling effect of this
surface system was first validated
against 48 h Pseudomonas aeruginosa
PAO1 biofilms. By actuating the square-shaped surface topographies with a height of 10 µm, side width of 2 µm, and inter-pattern distance of 5 µm for 3 min, more than 99.9% (3 logs) biofilm cells were removed. Because this strategy can be applied to different materials, it is a new generation of antifouling technology with
promising biomedical applications.