Department of Experimental Physics, Saarland University, Campus E2 9, 66123 Saarbrücken, Germany.
INM - Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
Nanoscale. 2019 Nov 14;11(42):19713-19722. doi: 10.1039/c9nr04375f. Epub 2019 Oct 10.
Microbial adhesion and the subsequent formation of resilient biofilms at surfaces are decisively influenced by substrate properties, such as the topography. To date, studies that quantitatively link surface topography and bacterial adhesion are scarce, as both are not straightforward to quantify. To fill this gap, surface morphometry combined with single-cell force spectroscopy was performed on surfaces with irregular topographies on the nano-scale. As surfaces, hydrophobized silicon wafers were used that were etched to exhibit surface structures in the same size range as the bacterial cell wall molecules. The surface structures were characterized by a detailed morphometric analysis based on Minkowski functionals revealing both qualitatively similar features and quantitatively different extensions. We find that as the size of the nanostructures increases, the adhesion forces decrease in a way that can be quantified by the area of the surface that is available for the tethering of cell wall molecules. In addition, we observe a bactericidal effect, which is more pronounced on substrates with taller structures but does not influence adhesion. Our results can be used for a targeted development of 3D-structured materials for/against bio-adhesion. Moreover, the morphometric analysis can serve as a future gold standard for characterizing a broad spectrum of material structures.
微生物黏附以及随后在表面形成有弹性的生物膜，这主要取决于基质的特性，例如表面形貌。迄今为止，定量联系表面形貌和细菌黏附的研究很少，因为这两者都不容易定量。为了填补这一空白，我们对纳米级不规则形貌的表面进行了表面形态计量学和单细胞力谱学研究。作为表面，我们使用了疏水性硅片，硅片经过蚀刻，以展示与细菌细胞壁分子相同尺寸范围的表面结构。表面结构通过基于闵可夫斯基函数的详细形态计量分析进行了特征描述，揭示了定性相似的特征和定量不同的扩展。我们发现，随着纳米结构尺寸的增加，黏附力以一种可以通过细胞壁分子系留的表面积来定量的方式降低。此外，我们观察到一种杀菌作用，在具有更高结构的底物上更为明显，但不影响黏附。我们的结果可用于有针对性地开发用于/对抗生物黏附的 3D 结构材料。此外，形态计量分析可以作为未来广泛材料结构的特征描述的黄金标准。
