Multifunctional slippery nanoemulsion-infused porous nitric oxide-releasing surfaces

The need for biocompatible materials for medical devices remains critical, as complications such as infection, thrombosis, and biofouling significantly contribute to medical device failure and patient morbidity and mortality. In recent years, nitric oxide (NO)-releasing technologies have been explored to mitigate bacterial infections, particularly those stemming from common gram-positive and gram-negative bacterial pathogens. However, NO-releasing materials do not inherently possess anti-fouling capabilities. Combination strategies that use NO and anti-fouling surfaces (e.g., slippery lubricant-infused porous surfaces) have been explored to compensate for the deficit. In this work, a novel material was developed and assessed that combines the antibacterial capabilities of a NO-releasing substrate with the anti-fouling effects of a nanoemulsion (NE)-infused slippery surface. Using a covalently bound NO donor (S-nitroso-N-acetylpenicillamine, SNAP) to poly(dimethylsiloxane) (PDMS) and infused with a NE, denoted as SNAP-PDMS-NE, the NO release was sustained for 7 days. In addition to the prolonged NO release, the infused NE layer maintained a slippery nature and sliding angle below 20° for 7 days. The reported NO-releasing NE-swelled surface efficiently reduced Staphylococcus aureus adhesion by 3.5 log and Escherichia coli adhesion by 1.5 log after 24 h, reduced platelet adhesion by 89.92 %, and remained cytocompatible with relative cell viability greater than 70 %.