Nanoemulsion-Mediated Encapsulation of Podoviridae Bacteriophages for Antifouling Medical Devices

Abstract

The recent resurgence of antimicrobial resistance, driven by the overuse and misuse of antibiotics in healthcare, has underscored the need for research in antibacterial approaches, or a resurgence of old ideas. One historically popular therapy was the use of bacteriophages, which are naturally occurring viruses that infect bacterial pathogens. The discovery of penicillin in the late 1920s led to the subsequent decline in the development of bacteriophage therapies. However, billions of dollars are now being spent on developing antibiotics, yet these drugs quickly become less effective as antimicrobial-resistant pathogens emerge. These infections are a major cause of medical device failure; another source is thrombus formation, particularly in indwelling devices. Strategies to combat infection and thrombus formation simultaneously are needed. Herein, cost-effective bacteriophages were encapsulated in an oil-based nanoemulsion, which was subsequently embedded into a medical-grade material. The nanoemulsion forms a slippery surface that uses a passive strategy to repel bacterial cells and blood proteins, thereby mitigating infection and clotting rates. With the nature of the nanoemulsion, the phages were released from the material slowly at a rate of 2.5 ± 0.48 × 103 plaque forming units (PFU) cm–2 every 24 h. Additionally, the combination of passive and active antibacterial strategies achieved 88.9 ± 4.6% killing efficiency against the common pathogen Escherichia coli. The nanoemulsion-modified materials also exhibited significant decreases in fibrinogen adsorption, a key initiator of clot formation on biomaterial surfaces. The bacteriophage nanoemulsion group showed a 78.9 ± 16.5% reduction in adsorbed fibrinogen compared to the unmodified ePTFE material. This combined therapy demonstrated enhanced antifouling and antibacterial performance while maintaining both cyto- and hemocompatibility, positioning it as a promising antibacterial material for future biomedical applications.