Rechargeable Antibacterial and Antifungal Polymeric Silver Sulfadiazines

Poly(methyl methacrylate) (PMMA)-based rechargeable antibacterial and antifungal polymeric silver sulfadiazines were prepared by copolymerizing acryloyl sulfadiazine with methyl methacrylate and sequentially treating the copolymers with dilute silver nitrate aqueous solutions. The chemical structures of the samples were characterized by FT-IR, H-1-NMR, XPS, and TGA analyses. On contact, the PMMA-based polymeric silver sulfadiazines provided 100% inactivation of 10(8)-10(9) CFU/mL of Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria) in 10 min, and Candida tropicalis (yeast) in 30 min. Kirby-Bauer test data indicated that the antibacterial and antifungal effects were achieved through contact kill; no silver ions leached out of the new copolymers. The antibacterial and antifungal functions were stable for at least 12 months under normal storage conditions. Silver nitrate treatments regenerated any lost of antibacterial and antifungal activity; this recharging can be repeated as needed to achieve long-term protection. These properties make the new PMMA-based polymeric silver sulfadiazines attractive candidates for a broad range of medical (orthopedic), dental, and other related applications to reduce the risks of bacterial and fungal contamination on high-touch/high-risk surfaces and foreign body-related infections.