Anti-Biofouling Performance of Slippery, Lubricant-Infused Swollen Silicone Tubing

With the rise of multi- and pan-drug resistant organisms resulting from overuse of antibiotic-based treatments, preventing nosocomial infections is a timely and important goal. While biofilm formation on urinary catheters remains a leading cause of nosocomial infection, an effective fix remains elusive. Swelling of poly-dimethy siloxane (silicone) in silicone oil produces a slippery, hydrophobic, and extremely flat liquid surface layer that surrounds the solid polymer surface. We evaluated the anti-biofouling performance of this inexpensive and simple modification of an existing catheter material. Using Pseudomonas aeruginosa as a model organism, we quantified biofilm growth on swollen and un-swollen silicone by quantitative crystal violet assay and found an 8-fold reduction in biofilm formation on swollen silicone at lower shear rates (10 s^-1, 47.8 s^-1) and a 134-fold reduction at the highest tested shear rate (270.4 s^-1) after 48h of closed-loop culture. Further, a simple, 5s washing step almost entirely removes any traces of a biofilm present on the swollen tubing. Confocal imaging confirms that biofilm formation is substantially reduced on swollen silicone. Given the excellent anti-biofouling performance, simplicity of manufacture, inexpensive production, and even improvements to patient comfort, this approach shows significant potential to be clinically implemented and subsequently reduce worldwide incidence of catheter-associated infections.