Decreased Bacterial Activity on Nano‐patterned PDMS Replica for Catheter‐associated Infection Prevention

Abstract

ExperimentHere, a nano‐patterned polydimethylsiloxane (PDMS, a commonly used catheter material) replica was fabricated by using nanotubular anodized titanium (ATi) as the template. In vitro bacterial studies using S. aureus, E. coli, P. aeruginosa and S. epidermidis were conducted to assess the effectiveness of the nano‐patterned PDMS (nano‐PDMS) at inhibiting bacterial growth. In addition, human fibroblast and endothelial cell assays were conducted to determine the influence of the nanostructure on mammalian cell behavior as a measurement of toxicity. To elucidate the mechanisms of how surface topographies affect cell/ bacteria adhesion, the protein interactions with different surfaces were also investigated by using the bicinchoninic acid (BCA) protein assay.ResultsAs expected, the nano‐patterned structures were fabricated successfully on PDMS surface. Results showed that nano‐PDMS inhibited the growth of all the four types of bacteria after 24h and 48h, respectively. Moreover, data suggested the effectiveness of bacteria inhibition reached above 50%, all without employing an antibiotic (Fig. 1). It was also found that nano‐PDMS increased both fibroblast and endothelial cell adhesion and, thus, were non‐toxic to mammalian cells (Fig. 2). BCA results indicated that the amount of total proteins adhered on the nano–PDMS surfaces was slightly higher than on plain PDMS surfaces, presumably due to the increased surface area and change of adhesion sites.imageimageConclusionsThe nano topography on PDMS could inhibit bacterial growth significantly while remaining non‐toxic to mammalian cells, and thus should strongly be considered for use in catheters.