Aspect ratio of nano/microstructures determines Staphylococcus aureus adhesion on PET and titanium surfaces

AIMS: Joint infections cause premature implant failure. The avoidance of bacterial colonization of implant materials by modification of the material surface is therefore the focus of current research. In this in vitro study the complex interaction of periodic structures on PET and titanium surfaces on the adhesion of Staphylococcus aureus is analysed. METHODS AND RESULTS: Using direct laser interference patterning as well as roll-to-roll hot embossing methods, structured periodic textures of different spatial distance were produced on surfaces and S. aureus were cultured for 24h on these. The amount of adhering bacteria was quantified using fluorescence microscopy and the local adhesion behaviour was investigated using scanning electron microscopy. For PET structures, minimal bacterial adhesion was identified for an aspect ratio of about 0·02. On titanium structures, S. aureus adhesion was significantly decreased for profile heights of < 200nm. Our results show a significantly decreased bacterial adhesion for structures with an aspect ratio range of 0·02 to 0·05. CONCLUSIONS: We show that structuring on surfaces can decrease the amount of S. aureus on titanium and PET as common implant materials. SIGNIFICANCE AND IMPACT OF THE STUDY: The study highlights the immense potential of applying specific structures to implant materials to prevent implant colonization with pathogen bacteria.