Effect of nanodiamond powders on the viability and production of reactive oxygen and nitrogen species by human endothelial cells

Diamond nanoparticles find numerous applications in industry and medicine. For medical applications, biocompatibility of diamond particles is of critical importance. Various medical implants are coated by carbon coating. The purpose of our study was to investigate the effect of diamond powders, MW/RF1 (produced by the microwave/radio frequency plasma activated chemical vapour deposition method), RF1 (produced by the radio frequency plasma activated chemical vapour deposition method). UDD (manufactured by the detonation method) and GRAF (graphite powder) on the viability of immortalised human umbilical vein endothelial cells (HUVEC-ST) and production of reactive oxygen species and nitric oxide by these cells. The cells were incubated in the culture medium with diamond or graphite powders (2-100 mu g ml(-1)) for 24-72 h. MW/RF1 and RF1 did not affect significantly cell proliferation, estimated by the MIT assay. However, UDD exhibited a concentration-dependent cytotoxicity. The powders did not affect significantly cellular production of ROS estimated by oxidation of H2DCF-DA (2',7'-dichlorodihydrofluorescein diacetate), except for UDD and GRAF. In the concentration range studied, diamond and graphite powders did not induce any statistically significant changes in the production of nitric oxide, estimated with the fluorogenic probe 3-amino-4 aminomethyl 2',7'difluorescein diacetate (DAF-FM-DA), except for UDD and GRAF. (C) 2011 Elsevier B.V. All rights reserved.