Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.
Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstrasse 1, Mainz 55131, Germany.
ACS Appl Mater Interfaces. 2020 May 13;12(19):21192-21200. doi: 10.1021/acsami.9b22621. Epub 2020 Mar 6.
Biofilm formation is most commonly combatted with antibiotics or biocides. However, proven toxicity and increasing resistance of bacteria increase the need for alternative strategies to prevent adhesion of bacteria to surfaces. Chemical modification of the surfaces by tethering of functional polymer brushes or films provides a route toward antifouling coatings. Furthermore, nanorough or superhydrophobic surfaces can delay biofilm formation. Here we show that submicrometer-sized roughness can outweigh surface chemistry by testing the adhesion of to surfaces of different topography and wettability over long exposure times (>7 days). Gram-negative and positive bacterial strains are tested for comparison. We show that an irregular three-dimensional layer of silicone nanofilaments suppresses bacterial adhesion, both in the presence and absence of an air cushion. We hypothesize that a 3D topography can delay biofilm formation (i) if bacteria do not fit into the pores of the coating or (ii) if bending of the bacteria is required to adhere. Thus, such a 3D topography offers an underestimated possibility to design antibacterial surfaces that do not require biocides or antibiotics.
生物膜的形成通常通过抗生素或杀生剂来对抗。然而，细菌毒性已被证实且耐药性不断增加，这增加了对替代策略的需求，以防止细菌黏附于表面。通过将功能性聚合物刷或薄膜键合到表面上进行化学修饰，为防污涂层提供了一种途径。此外，纳米粗糙或超疏水表面可以延迟生物膜的形成。在这里，我们通过测试不同形貌和润湿性表面上的长达 7 天以上的长时间暴露下的黏附情况，表明亚微米级粗糙度可以通过表面化学来克服。我们测试了革兰氏阴性和阳性细菌菌株以作比较。我们表明，硅纳米丝的不规则三维层在存在和不存在气垫的情况下均能抑制细菌黏附。我们假设，三维形貌可以延迟生物膜的形成（i）如果细菌不能适应涂层的孔，或者（ii）如果细菌弯曲以黏附。因此，这种三维形貌提供了一种被低估的可能性，可以设计出不需要使用杀生剂或抗生素的抗菌表面。
