In vitro behavior of osteoblast-like cells on titanium surface blasted with Al2O3 and glass beads

Abstract

Blasting titanium with abrasive particle is the method used to generate surface topography and roughness to improve cellular responses. The behavior of MC3T3-E1 cells was compared on six different titanium surfaces: polished titanium (Ti-polish), titanium blasted with glass beads (SiO₂) particles of 50 or 100 µm in size (50SiO₂-Ti, 100SiO₂-Ti) and titanium blasted with Al₂O₃ particles of 50,100 or 250 µm in size (50Al₂O₃-Ti, 100Al₂O₃-Ti, 250Al₂O₃-Ti). Profilometry showed the comparable roughness values for the surface blasted with the same size particle, (Sa= 0.5340, 0.5288 µm for 50SiO₂-Ti and 50Al₂O₃-Ti) (Sa=0.6323, 0.6343 µm for 100SiO₂-Ti and 100Al₂O₃-Ti). While the 250Al₂O₃-Ti had the highest roughness values (Sa= 1.5168 µm). Both the SiO₂ and Al₂O₃ blasted surfaces were hydrophilic materials but only Al₂O₃ blasted surface could support higher amount of fibrin formation after 5 minutes. In addition, cells seeded on 250Al₂O₃ –Ti showed faster rate of adhesion at 30 min, higher rate of proliferation at day 2, higher expression of collagen type I and osteocalcin at day 7 than the other surfaces. Moreover, increased expression of osteocalcin at day 14 and more alizarin red-S staining at day 14 were observed on Al₂O₃ blasted surfaces compared to the SiO₂ blasted surfaces. However, no significant differences in cell response among the groups, which prepared by different size of Al₂O₃ were detected. The results of this study indicated that Al₂O₃ blasted surface could support the osteoblast adhesion, differentiation and mineralization better than SiO₂.These results suggested that the 250Al₂O₃ –Ti supported the greatest initial adhesion, proliferation and initial gene expression of MC3T3-E1 cells.