Antibiotic release from F-doped nanotubular oxide layer on TI6AL4V alloy to decrease bacterial viability.

ABSTRACT

We aimed to evaluate the release of two antibiotics gentamicin and vancomycin loaded into F-doped nanotubular anodic oxide layers, as well as their bactericide effect. F-doped nanotubular oxide layers fabricated on Ti-6Al-4V loaded with gentamicin (Gm), vancomycin (Vm) and their mixture (Gm + Vm) by a previously described loading method. Antibiotic release was studied by RP-HPLC and by a biological method. Bactericidal activity was evaluated by a bacterial adherence protocol described previously using on three clinically important bacterial species. The antibiotic release steady up to 120 and 180 min for Gm and Vm, respectively, and despite the antibiotic concentration decreased, their biological activity was maintained over time. The number of living bacteria of three species tested on NT-Gm specimens was significantly lower than on NT specimens without antibiotics (P < 0.01). There are significant differences among NT-Gm and NT-Gm + Vm specimens (P < 0.05) for S. aureus 15981, S. epidermidis ATCC 35984, and P. aeruginosa ATCC 27853 and no differences between NT-Vm and NT-Gm + Vm for staphylococci (P > 0.05). In conclusion, this Gm + Vm loading method added to the properties of F-doped nanotubular oxide layers fabricated on Ti-6Al-4V, and therefore surfaces with antibacterial, biocompatible, tissue integration stimulating and spread-spectrum bactericidal properties can be obtained.