Two types of bacteriophage-modified alginate hydrogels as antibacterial coatings for implants

Abstract

BackgroundThe overuse of antibiotics has led to the rise of drug-resistant bacterial infections in the medical industry. In this study we made two kinds of implant coatings loaded with bacteriophage, a safe and highly-specific bacteriocidal viral particle, and examined the coatings’ antibacterial efficacies and bone cell biocompatibility. MethodsPurified lytic bacteriophages were conjugated to the surface of an alginate hydrogel (phage-conjugated sample) and embedded in the hydrogel matrix (phage-embedded sample.) Compared to the phage-embedded sample, the phage-conjugated sample had a lower contact angle (p < 0.01); preserved fewer phage particles per sample (p < 0.001) yet had a higher antibacterial efficacy in 2 h (p < 0.001). The phage-conjugated sample stimulated higher bone cell growth (p < 0.05) and mineralization (p < 0.01). The SEM micrographs show that bacterial biofilms did not form on either sample at 24 h. Significant findingsThis is the first time lytic phage particles were anchored to hydrogel surface and made into tissue regenerative materials. The phage-conjugated alginate hydrogel prevented bacterial growth by 84% in 2 h and biofilm formation after 24 h. Meanwhile it promoted bone cell growth by 28.8% and mineralization by 43.1%. It can potentially be used as an non-antibiotic-based antibacterial coating for orthopedic implants.