Liquid-Infused Silicone As a Biofouling-Free Medical Material

Abstract

There is a dire need for infection prevention strategies that do not require the use of antibiotics, which exacerbate the rise of multi-and pan-drug resistant infectious organisms. An important target in this area is the bacterial attachment and subsequent biofilm formation on medical devices (e.g., catheters). Here we describe non-fouling, lubricant-infused slippery polymers as proof-of-concept medical materials that are based on oil-infused polydimethylsiloxane (iPDMS). Planar and tubular geometry silicone substrates can be infused with non-toxic silicone oil to create a stable, extremely slippery interface that exhibits exceptionally low bacterial adhesion and prevents biofilm formation. Analysis of a flow culture of Pseudomonas aeruginosa through untreated PDMS and iPDMS tubing shows at least an order of magnitude reduction of biofilm formation on iPDMS, and almost complete absence of biofilm on iPDMS after a gentle water rinse. The iPDMS materials can be applied as a coating on other polymers or prepared as simply as taking a silicone tubing and immersing it in a silicone oil, and are compatible with traditional sterilization methods. As a demonstration, we show the preparation of silicone-coated polyurethane catheters and significant reduction of Escherichia coli and Staphylococcus epidermidis biofilm formation on the catheter surface. This work represents an important first step towards a simple and effective means of preventing bacterial adhesion on a wide range of materials used for medical devices.

Immobilized liquid layers: A new approach to anti-adhesion surfaces for medical applications

“…27 Epstein et al 11 demonstrated that IL layers on ePTFE reduced biofilm coverage of Staphylococcus aureus by 97.2% and Escherichia coli by 96% after 48 h, as well as Pseudomonas aeruginosa by 99.6% after seven days of growth under gentle flow (10 mL/min). Researchers working on IL layers fabricated using other methods have found similar results with these species both under static 27,54 and flow conditions 27,43 ( Figure 8). However, Li et al 32 found that not all bacterial strains are equally repelled by lubricantinfused surfaces.…”

Transparent antifouling material for improved operative field visibility in endoscopy

“…One particular consideration is that liquid-infused surfaces significantly reduce bacterial adhesion (18,19,24,25,38), which is a key advantage in endoscopy, considering the magnitude of the tragedy at the University of California, Los Angeles Medical Center, where seven patients were infected after the procedure with Carbapenem-resistant Enterobacteriaceae due to a lack of sufficient sterilization (39). More recently, outbreaks have occurred in hospitals in Seattle, Pittsburgh, and Chicago (40).…”

“…The formation of a stable lubricant overlayer on the surface creates a dynamic slippery barrier that protects the underlying substrate from direct contact with polluted media, thus drastically lowering the adsorption of various serious contaminants including bacteria (18,19) and proteins (20)(21)(22). This new, non-fouling material can be designed to perform under flow (23,24), provide enhanced damage tolerance (15,16) and selfhealing capabilities (11), or be integrated with a vascularized network that secretes the lubricant to repair the interface (25,26).…”

Transparent self-cleaning lubricant-infused surfaces made with large-area breath figure patterns

“…1°) [14,15]. Previous studies have also demonstrated that the SLIPS can provide self-cleaning property under high relative humidity, withstand high pressures, exhibit self-healing after physical damage, prevent attachment of ice and bacteria, and so on [14,[16][17][18][19][20][21][22]. Similar to the role played by the structures in lotus-inspired superhydrophobic surfaces, the structures hold the lubricant liquid to form a stable liquid/solid composite surface in SLIPS.…”