The influence of bone-graft bio-functionalization with plasma of argon on bacterial contamination.

Plasma of argon was demonstrated to improve protein and cell adhesion on bone grafts. On the other hand, increased surface energy and hydrophilicity could potentially amplify the risks of graft surface contamination in a clinical environment. The aim of the present study was to in vitro verify if the plasma of argon treatment could alter the graft characteristics affecting its ability to remain sterile. Six graft materials produced by different company were selected for this study, and randomly split by allocation either in the test (Plasma of argon treatment for 20') or the control group (only removed from the plastic sterile vials). To replicate the surgical work flow, both test and control samples were left 2 min in the clinical environment simulated conditions. Samples were therefore transferred in a Biosafety level 2 culture room. Bacterial growth analysis was performed. Optical density at 600 nm was measured as readout of bacterial growth and, after 24 hours, colony forming unit (CFU) was evaluated. Statistical analysis was performed by using the ordinary one-way ANOVA. The optical density confirmed no significant differences within groups and the number of CFU/ml for each measured sample (test and control) failed to present significant differences. Data from the present study highlighted that surface activation using plasma of argon did not affect the degree of contamination of the bone grafts, allowing to maintain a required sterility of the surface.