Effect of different surface nanoroughness of titanium dioxide films on the growth of human osteoblast-like MG63 cells
Abstract
Cell behavior depends strongly on the physical and chemical properties of the material surface, for example, its chemistry and topography. The authors have therefore assessed the influence of materials of different chemical composition (i.e., glass substrates with and without TiO2 films in anatase form) and different surface roughness (Ra = 0, 40, 100, or 170 nm) on the adhesion, proliferation, and osteogenic differentiation of human osteoblast-like MG63 cells.
On day 1 after seeding, the largest cell spreading area was found on flat TiO2 films (Ra = 0 nm). On TiO2 films with Ra = 170 nm, the cell spreading area was larger and the number of initially adhering cells was higher than the values on the corresponding uncoated glass.
On day 3 after seeding, the cell number was higher on the TiO2 films (Ra = 0 and 40 nm) than on the corresponding glass substrates and the standard polystyrene dishes. On day 7, all TiO2 films contained higher cell numbers than the corresponding glass substrates, and the cells on the TiO2 films with Ra = 40 and 100 nm also contained a higher concentration of beta-actin.
These results indicate that TiO2 coating had a positive influence on the adhesion and subsequent proliferation of MG63 cells. In addition, on all investigated materials, the cell population density achieved on day 7 decreased with increasing surface roughness.
The concentration of osteocalcin, measured per mg of protein, was significantly lower in the cells on rougher TiO2 films (Ra = 100 and 170 nm) than in the cells on the polystyrene dishes. Thus, it can be concluded that the adhesion, growth, and phenotypic maturation of MG63 cells were controlled by the interplay between the material chemistry and surface topography, and were usually better on smoother and TiO2-coated surfaces than on rougher and uncoated glass substrates.