Vasudevan Ravikumar, Kennedy Alan J, Merritt Megan, Crocker Fiona H, Baney Ronald H
Department of Materials Science and Engineering, University of Florida, Gainesville, FL, USA.
U.S. Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, MS, USA.
Colloids Surf B Biointerfaces. 2014 May 1;117:225-32. doi: 10.1016/j.colsurfb.2014.02.037. Epub 2014 Mar 4.
Microscale patterned surfaces have been shown to control the arrangement of bacteria attached to surfaces. This study was conducted to examine the effect of patterned topographies on bacterial fouling using Enterobacter cloacae as the test model. E. cloacae is an opportunistic pathogen involved frequently in nosocomial infections. It is an important model organism to be studied in the context of healthcare associated infections (HAI) and polydimethylsiloxane (PDMS) based urinary catheter fouling. Patterned surfaces, such as Sharklet™, have shown the promise of being a benign surface treatment for prevention of catheter associated urinary tract infections (CAUTI). To the best of our knowledge, inhibition of fouling by E. cloacae has not been demonstrated on microscale patterned PDMS surfaces. In this study, the Sharklet™ and smooth PDMS surfaces were used as controls. All pattern surfaces had statistically significantly lower percentage area coverage compared to the smooth PDMS control. A cross type feature (C-1-PDMS), demonstrated the most significant reduction in percent area coverage, 89% (p<0.01, α=0.05), compared to the smooth PDMS control and all other patterned test surfaces. Additionally, theoretical calculations show that C-1-PDMS is the only surface predicted to hold the thermodynamically stable Cassie state, which occurs due to trapping air pockets at the liquid-solid interface. Combined the results provide new insights for designing environmentally benign, novel, microscale patterned surfaces for restricting bacterial fouling.
微尺度图案化表面已被证明可以控制附着在表面的细菌的排列。本研究以阴沟肠杆菌为测试模型，旨在研究图案化形貌对细菌污染的影响。阴沟肠杆菌是一种机会致病菌，经常参与医院感染。在医疗相关感染（HAI）和基于聚二甲基硅氧烷（PDMS）的导尿管污染的背景下，它是一种重要的研究模型生物。图案化表面，如Sharklet™，已显示出有望成为预防导尿管相关尿路感染（CAUTI）的良性表面处理方法。据我们所知，在微尺度图案化的PDMS表面上，尚未证明阴沟肠杆菌对污垢的抑制作用。在本研究中，Sharklet™和平滑PDMS表面用作对照。与光滑PDMS对照相比，所有图案化表面的面积覆盖率百分比在统计学上均显著降低。与光滑PDMS对照和所有其他图案化测试表面相比，一种十字型特征（C-1-PDMS）的面积覆盖率百分比降低最为显著，为89%（p<0.01，α=0.05）。此外，理论计算表明，C-1-PDMS是唯一预测能保持热力学稳定的卡西状态的表面，这种状态是由于在液固界面捕获气穴而产生的。综合这些结果为设计环境友好、新颖的微尺度图案化表面以限制细菌污染提供了新的见解。
