M.C. Parker, A. Shome, V.D. Pinon, N. Crutchfield, M. Garren, E.J. Brisbois, H. Handa
University of Georgia,
United States
Keywords: anti-biofouling organogel, nitric oxide, SLIPS
Summary:
Organogels are three-dimensional networks which entrap organic liquids to offer superior mechanical, thermal, and environmental stability compared to traditional hydrogels. Their application versatility results in droplet manipulation uses, surface engineering, drug delivery, and anti-fouling technologies. The lubricating phase plays a critical role in these systems by repelling surface-adhered bacteria, cells, and proteins. However, widely studied slippery organogels with anti-biofouling properties face several limitations: complicated fabrication schemes, reliance on fluorinated or organic solvents as infused lubricants, insufficient cytotoxicity testing, and limited long-term chemical durability, hindering their biomedical utility. These organogels depend heavily on the passive lubricant layer, which is susceptible to depletion, volatilization, and migration over time. This emphasized the need for organogel systems that integrate active anti-biofilm functionality alongside passive lubrication to achieve sustained and reliable surface protection. To address these challenges, we developed a dual-action slippery organogel that combines passive surface repellency with active biological intervention to prevent biofilm formation on medical device surfaces. Nitric oxide (NO), an endogenously produced antimicrobial and antithrombotic agent, has previously been incorporated into commercial-grade silicone polymers with lubricant infusion, demonstrating anti-biofouling properties. However, these approaches are limited to commercial silicone substrates and lack mechanical tunability and substrate versatility. Our work introduces a chemically facile, mechanically robust organogel with substrate-independent applicability. Through capitalizing on the amine-epoxy ring-opening reaction, the stand-alone organogel is loaded with NO donor, S-nitroso-N-acetylpenacillamine (SNAP), and infused with silicone oil to achieve impeccable sustained anti-biofouling and anti-biofilm properties (PT2-Oil(SNAP)). Biofilm formation on blood-contacting medical devices is a major contributor to hospital-acquired infections, which remain a leading cause of patient mortality in the United States. In this novel investigation of a dual-action slippery organogel with both bioactive and biopassive components, we examined biofilm inhibition in addition to platelet adhesion, protein repellence, cytocompatibility and hemocompatibility. Due to their irreversible attachment and cell signaling mechanisms, biofilms are very difficult to eradicate. To thoroughly investigate the biomass accumulation and eradication efficacy of Gram-negative E. coli and Gram-positive S. aureus on the standalone anti-biofouling organogel, samples underwent a static batch phase bacterial incubation followed by dynamic media supplementation for 3 days and 5 days. The combinatorial effectiveness of PT2-Oil(SNAP) significantly reduced E. coli and S. aureus over both 3- and 5-days. The antibiofouling organogel exhibits resistance to protein adhesion (>60%), biomass accumulation (>85%), and excellent platelet repellence (>80%). Furthermore, the slippery organogel can be extended to various substrates including polyurethanes, PVC, silicone, stainless steel, aluminum, and glass, providing universal applicability. Thus, both the active NO release and passive lubricant infusion embedded in our organogel matrix provides strong biological efficacy in vitro to combat nosocomial infection and demonstrates potential for in vivo applications.