Department of Experimental Physics, Saarland University, Saarbrücken, 66041, Germany.
Langmuir. 2012 May 8;28(18):7242-8. doi: 10.1021/la3004323. Epub 2012 Apr 25.
Controlling the interface between bacteria and solid materials has become an important task in biomedical science. For a fundamental and comprehensive understanding of adhesion it is necessary to seek quantitative information about the involved interactions. Most studies concentrate on the modification of the surface (chemical composition, hydrophobicity, or topography) neglecting, however, the influence of the bulk material, which always contributes to the overall interaction via van der Waals forces. In this study, we applied AFM force spectroscopy and flow chamber experiments to probe the adhesion of Staphylococcus carnosus to a set of tailored Si wafers, allowing for a separation of short- and long-range forces. We provide experimental evidence that the subsurface composition of a substrate influences bacterial adhesion. A coarse estimation of the strength of the van der Waals forces via the involved Hamaker constants substantiates the experimental results. The results demonstrate that the uppermost layer is not solely responsible for the strength of adhesion. Rather, for all kinds of adhesion studies, it is equally important to consider the contribution of the subsurface.
控制细菌与固体材料之间的界面已成为生物医学科学中的一项重要任务。为了对粘附进行基础和全面的理解，有必要寻求有关涉及相互作用的定量信息。大多数研究都集中在表面的改性（化学成分，疏水性或粗糙度）上，但是忽略了本体材料的影响，本体材料总是通过范德华力对整体相互作用做出贡献。在这项研究中，我们应用原子力显微镜（AFM）力谱和流动室实验来探测金黄色葡萄球菌（Staphylococcus carnosus）与一组定制的硅片的粘附，从而可以分离短程和长程力。我们提供的实验证据表明，基底的亚表面组成会影响细菌的粘附。通过涉及的哈克常数对范德华力的强度进行粗略估计，证实了实验结果。结果表明，最上层并不仅仅负责粘附的强度。相反，对于所有类型的粘附研究，同样重要的是要考虑亚表面的贡献。
