Modelling the interaction between bacterial cells and laser-textured surfaces

The influence of surface topography resulting from ultrashort pulsed laser texturing on bacterial cell adhesion is studied as a method for preventing contamination on stainless steel components. The initial adhesion of a single spherical cell on a rough surface prior to the onset of any chemical or biological effect is simulated with a numerical approach including non-covalent interactions between the cell and textured substrate. The study demonstrates that when asperities are large enough to allow the cell to occupy valleys between two adjacent protrusions, the cell is protected from hydrodynamic turbulence and is therefore more prone to adhere to the substrate. Results pave the way to validating, in quantitative terms, hypotheses relating to the influence of surface topography on bacterial growth. Two different levels of anisotropy are taken into account to contrast the high adaptability of spherical cells, demonstrating that laser texturing can invoke a specific biological response.