Effects of hydrogenated TiO2 nanotubes on macrophage secretion and expression of cytokines and chemokines.

Background: Modified titanium substrates with titanium dioxide nanotubes have broad usage as implant surface treatment and as drug- delivery systems. Their performance in most of these applications is highly dependent on there morphology. Macrophage behavior was thought to be regulated by nanostructured titanium which has been considered as a very promising candidates for dental implants. Aim/Hypothesis: To investigate effects of hydrogenated TiO2 nanotubes on macrophage behavior, secretion and expression of pro- inflammatory cytokines and chemokines. Material and Methods: Macrophage- like J744A.1 cells were cultured on three types of Ti surface- hydrogenated TiO2 nanotubes, unmodified TiO2 nanotubes, and Ti substrates (as control) for 4, 24 and 48 hours. Macrophage adhesion and proliferation were assessed using CCK-8 assay. Levels of pro-inflammatory cytokines (TNF- a, IL- 1b and IL- 6) and chemokines (MCP-1 and MIP-1a) secreted into the supernatant were measured using the Cytometric Bead Arrays kit. TNF-a, MCP-1 and MIP- a gene expression were quantitatively analysed by real- time PCR. Results : These show that TiO2 nanotube surfaces, especially hydrogenated TiO2 nanotubes, benefited macrophage adhesion and prolifera-tion, and reduced protein secretion and mRNA expression of pro- inflammatory cytokines and chemokines. Conclusions and Clinical Implications : TiO2 nanotube surfaces, especially hydrogenated TiO2 nanotubes, reduced inflammatory response in vitro, which might induce rapid osseointegration in implants with hydrogenated TiO2 nanotube surfaces in vivo. [ABSTRACT FROM AUTHOR]