Biomimetic Diamond-like Carbon coated Titanium Inhibits RANKL-dependent Osteoclast Differentiation in vitro

To examine the effects of titanium (Ti) coated with biomimetic diamond-like carbon (DLC) on osteoclast differentiation and bacterial biofilm formation, RAW264.7 cells and Porphyromonas gingivalis (P. g) were grown on Ti disks without DLC (control), or with DLC (DLC-treated). Real-time quantitative reverse transcriptase-polymerase chain reaction analysis showed that TRAP and cathepsin K mRNA levels in RAW264.7 cultured on DLC?treated Ti disks with soluble receptor activators for NF-?B ligand (sRANKL) were significantly lower than those of control Ti disks. Similarly, DLC-treated Ti decreased the expression of NFATc1 protein in sRANKL-stimulated RAW264.7 cells. Futher, reduced P. g biofilm formation was observed on DLC?treated disks as compared with the biofilm on control Ti disks. These results, taken together, suggested that DLC altered osteoclast differentiation and biofilm formation of P.g, which could promise long-term success of implant therapy.