Engineered antifouling microtopographies – correlating wettability with cell attachment

Abstract

Bioadhesion and surface wettability are influenced by microscale topography. In the present study, engineered pillars, ridges and biomimetic topography inspired by the skin of fast moving sharks (Sharklet AF™) were replicated in polydimethylsiloxane elastomer. Sessile drop contact angle changes on the surfaces correlated well (R² = 0.89) with Wenzel and Cassie and Baxter's relationships for wettability. Two separate biological responses, i.e. settlement of Ulva linza zoospores and alignment of porcine cardiovascular endothelial cells, were inversely proportional to the width (between 5 and 20 μm) of the engineered channels. Zoospore settlement was reduced by ∼85% on the finer (ca 2 μm) and more complex Sharklet AF™ topographies. The response of both cell types suggests their responses are governed by the same underlying thermodynamic principles as wettability.

Keywords:

• Biofouling
• biomimetic
• endothelial
• microtopography
• wettability
• ultrahydrophobic
• Ulva

Acknowledgements

ABB gratefully acknowledges the financial support of the Office of Naval Research (Contract No. N00014-02-1-0325) and the National Institutes of Health (Contract No. R01 DE 13492-01) to fund this research. JAC and MEC acknowledge financial support from the Office of Naval Research (Award N00014-02-05121). Porcine vascular endothelial cells were graciously donated by Dr Edward Block, Malcom Randall Veteran's Administration Hospital, Gainesville, FL.