Vascular prostheses with covalently bound gentamicin and amikacin reveal superior antibacterial properties than silver-impregnated ones--an in vitro study.

OBJECTIVE: This study aims to compare the antibacterial activities of vascular prostheses: silver-impregnated and modified with covalently immobilised antibiotics. MATERIALS AND METHODS: Six types of protein-sealed vascular prostheses were modified with amikacin and gentamicin according to the method described in the Polish Patent Office. Their antimicrobial properties were estimated against 14 reference and clinical strains and compared with those of InterGard Silver grafts. Cytotoxicity of the tested grafts was estimated against human skin fibroblasts. RESULTS: Prostheses modified with antibiotics in a stable covalent mode were found to be much more effective against bacterial growth and biofilm formation, as well as in case of methicillin-resistant Staphylococcus aureus (MRSA), than InterGard Silver. They inhibited the bacterial growth for at least 30 days, without losing higher than 10% of the initial amount of its drug content. They were also good, non-toxic matrices for growth of human skin fibroblasts. CONCLUSIONS: Prostheses modified with covalently immobilised antibiotic according to our technique are much more effective than InterGard Silver at protection against bacterial growth. They are also compatible with human skin fibroblasts.