Human osteoblast-like MG 63 cells on polysulfone modified with carbon nanotubes or carbon nanohorns

Composites of polysulfone (PSU) and 0.5, 1 or 2 wt.% of single-wall carbon nanohorns (SWCNHs) or multi-wall carbon nanotubes (MWCNTs) were prepared. Reinforcement with SWCNHs, and especially with MWCNTs, increased the tensile strength and the Young modulus of the material. The composites provided good support for the initial adhesion of human osteoblast-like MG 63 cells, and also for their further viability and metabolic activity. From day 1 to 3, the cell population doubling time was longer on composites with higher nanoparticle concentrations, and the DNA synthesis in cells on the composites was often lower than on unmodified PSU or on polystyrene culture dishes (PS). Nevertheless, from day 3 to 5, the proliferation activity of cells on the composites increased. On day 5, the concentrations of osteocalcin were lower in the cells on both pure PSU and PSU/nanocarbon composites than in the cells on polystyrene dishes, but on day 11, these differences equalized. The composites did not promote a significant increase in the concentration of ICAM-1, i.e., a marker of cell immune activation. Therefore, after some improvements, PSU/carbon nanotubule composites may be considered for application as bone tissue replacements.