Anti-bacterial coatings are often employed to elastomer surfaces to inhibit bacterial attachment. However, such approaches could lead to increased antibiotic resistance. Surface micro/nano texturing is gaining significant attention recently, as it is a passive approach to reduce bacterial adhesion to surfaces. To this end, this work aims to assess the anti-biofouling functionality of femtosecond laser-induced sub-micron topographies on biomedical elastomer surfaces. Femtosecond laser processing was employed to produce two types of topographies on stainless steel substrates. The first one was highly regular and single scale sub-micron laser-induced periodic surface structures (LIPSS) while the second one was multi-scale structures (MS) containing both sub-micron and micron-scale features. Subsequently, these topographies were replicated on Polydimethylsiloxane (PDMS) and Polyurethane (PU) elastomers to evaluate their bacterial retention characteristics. The sub-micron textured PDMS and PU surfaces exhibited long term hydrophobic durability up to 100 hours under the immersed conditions. Both LIPSS and MS topographies on PDMS and PU elastomeric surfaces were shown to substantially reduce (> 89%) the adhesion of gram-negative Escherichia coli bacteria. At the same time, the anti-biofouling performance of LIPSS and MS topographies was found to be comparable with that of lubricantimpregnated surfaces. The influence of physical defects on textured surfaces on the adhesion behaviour of bacteria was also elucidated. The results presented here are significant because the polymeric biomedical components that can be produced by replication cost-effectively, while their biocompatibility can be improved through femtosecond surface modification of the respective replication masters.
- biomedical elastomers
- laser induced periodic surface structures
- lubricant-impregnated surfaces