Adhesion and Growth of Human Osteoblast-Like Cell in Cultures on Nanocomposite Carbon-Based Materials

This paper summarizes our recent research on carbon nanoparticles (fullerenes, nanotubes, nanodiamond) as substrates for the adhesion, growth and phenotypic maturation of osteogenic cells. Fullerenes C-60 were deposited on microscopic glass coverslips in the form of continuous layers or layers micropatterned with bulge-like prominences of 128 +/- 8 nm, 238 +/- 3 nm, 326 +/- 5 nm and 1 043 +/- 57 nm in height. On continuous layers and on layers with prominences up to 326 +/- 5 nm, the adhesion and proliferation of human osteoblast-like MG 63 cells was similar as in control cells on polystyrene dishes. On layers with prominences 1 043 +/- 57 nm in height, the cells grew preferentially in grooves among the prominences. Similar cell responses were found in MG 63 cells cultured on continuous and micropatterned films made of binary C-60/Ti composites. In the second set of experiments, single-wall carbon nanohorns and multi-wall carbon nanotubes were mixed with a terpolymer of polytetrafluoroethylene, polyvinyldifluoride and polypropylene (in concentrations from 2 to 8 wt%) or with polysulfone (concentrations from 0.5 to 2 wt%). Adding carbon nanotubes to the terpolymer markedly improved the cell adhesion, spreading and subsequent growth of MG 63 cells, while the adhesion and growth of these cells on the pure and modified polysulfone were similar, which was probably due to a more hydrophilic character of polysulfone compared to the terpolymer. Nanocrystalline diamond (NCD) was deposited on silicon substrates and provided an excellent substrate for the adhesion, growth and osteogenic differentiation of MG 63 cells, measured by the concentration of osteocalcin. These beneficial effects of NOD films were further enhanced by boron doping, which can be attributed to increased electroactivity (i.e., electrical potential and conductivity) of these films.