Direct formation of amine functionality on DLC films and surface cyto-compatibility

Hydrogenated diamond-like carbon (H-DLC) films were synthesized on a p-type silicon wafer using radio frequency plasma composed of a mixture of Ar and C₂H₂ (ratio of 7 to 28). NH₃ plasma treatment was carried out to generate surface-terminal amino groups. The treated surfaces were characterized by Raman scattering, atomic force microscopy (AFM), water contact angle, and X-ray photoelectron spectroscopy (XPS). MC₃T ₃-E₁ mouse pre-osteoblasts were cultured on the samples, and cell morphology and proliferation were investigated to evaluate the cyto-compatibility. Cell-surface interactions were investigated by fluorescence microscopy in terms of spreading and proliferation. A cell count kit-8 (CCK-8 Beyotime) was employed to determine quantitatively the viable pre-osteoblasts. The formation of the amine functionality led to better cyto-compatibility on the DLC. © 2013 Elsevier B.V.