The Race for the Surface experimentally studied: In vitro assessment of Staphylococcus spp. adhesion and preosteoblastic cells integration to doped Ti-6Al-4V alloys

Objective: Implant-related infection is a devastating complication in orthopedic surgery. Aiming to minimize this problem, many material modifications have been developed. Here we report a study of a surface modification of Ti-6 Al-4V alloy using a methodology that enables the study of interactions between bacteria and the material in the presence of eukaryotic cells. Methods: We mixed different concentrations of collection or clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells using a previously published methodology, analyzing the minimal concentration of bacteria able to colonize the surface of the material through image analysis. Ti-6 Al-4V alloy was modified by anodization to obtain two F-doped nanostructured surfaces that have been previously described to have antibacterial properties. Results: Our results show similar bacterial adhesion results to nanoporous and nanotubular F-doped surfaces. The presence of preosteoblastic cells increases the adherence of all bacterial strains to both structures. No effect of the surface on eukaryotic cells adherence was detected. Conclusion: To our knowledge, this is the first time that anin vitro study emulating the race for the surface evaluates and compares the osseointegration and antibacterial properties between two nanostructured-modified titanium alloy surfaces. Clinical strains show different behavior from collection ones in bacterial adherence. The presence of cells increased bacterial adherence. NP and NT surface modifications didn't show significant differences in bacterial adhesion and preosteoblastic cells integration.