On the as-grown (upper column) and ScCO2-treated (lower column) TiO2 nanotubes of different diameters. The WST-1 assay was employed for further evaluating the fibroblast LY2835219 price cell proliferation on the as-grown and ScCO2-treated

TiO2 nanotubes of different diameters. Figure 8 shows the comparison of optical densities measured from the WST-1 assay results. We find that cell proliferation is lowest for the largest diameter of 100 nm in both as-grown and ScCO2-treated TiO2 nanotube samples. In addition, the ScCO2-treated TiO2 nanotubes appear to exhibit a monotonically increasing trend in cell proliferation with decreasing nanotube diameter. This trend is not so obvious in the as-grown samples. It indicates that human fibroblast cells show more obvious diameter-specific behavior on the ScCO2-treated TiO2 Evofosfamide datasheet nanotubes than on the as-grown ones. As discussed previously, the ScCO2 fluid can effectively remove the disordered Ti(OH)4 precipitates from the nanotube surface.

This may result in purer nanotube topography and thus more sensitive cell response to the diameter of the ScCO2-treated nanotubes. Eventually, for the smallest diameter of 15 nm, ScCO2-treated TiO2 nanotubes reveal higher biocompatibility than the as-grown sample. selleck Figure 8 Optical densities (QD) measured after the culture of human fibroblast cells. On the as-grown and ScCO2-treated TiO2 nanotubes of different diameters. Conclusions In conclusion, this study investigates SB-3CT the diameter-sensitive biocompatibility

of ScCO2-treated TiO2 nanotubes of different diameters prepared by electrochemical anodization. We find that ScCO2-treated TiO2 nanotubes can effectively recover their surface wettability under UV light irradiation as a result of photo-oxidation of C-H functional groups formed on the surface. It is demonstrated that human fibroblast cells show more obvious diameter-specific behavior on the ScCO2-treated nanotubes than on the as-grown ones, which can be attributed to the removal of disordered Ti(OH)4 precipitates from the nanotube surface by the ScCO2 fluid. This results in purer nanotube topography, stronger diameter dependence of cell activity, and thus higher biocompatibility for the 15-nm-diameter ScCO2-treated TiO2 nanotubes than the as-grown sample. This study demonstrates that the use of ScCO2 fluid can be an effective, appropriate, and promising approach for surface treatments or modifications of bio-implants. Authors’ information MYL is currently a visiting staff of the Department of Otolaryngology at Taipei Veterans General Hospital and also a Ph.D. candidate of National Yang-Ming University (Taiwan). CPL is currently a Master’s degree student of National Central University (Taiwan). HHH is a professor of the Department of Dentistry at National Yang-Ming University (Taiwan). JKC is an assistant professor of the Institute of Materials Science and Engineering at National Central University (Taiwan).