The effect of amino plasma-enhanced chemical vapor deposition-treated titanium surface on Schwann cells.

The surface modification of titanium and its alloys with amino group plasma-enhanced chemical vapor deposition has been proven to enhance the performance of implants on initial osteoblast bioactivity in vitro. However, scarce information on the effect of this kind of surface modification on nerve regeneration exists. In this study, the surface chemistry of pure Ti disks and surface-modified disks was examined using X-ray photoelectron spectroscopy. Cell counting kit 8 assay, 4,6-diamidino-2-phenylindole staining, flow cytometry, and scanning electron microscopy showed that either the p30% or cw + p30% mode-mediated surface significantly promote Schwann cell adhesion without any cytotoxicity compared with the pure Ti surface, and the cw + p30% group showed the best performance on cell adhesion. However, results of polymerase chain reaction and Western blot analyses showed that the mRNA and protein levels of glial cell-derived neurotrophic factor and nerve growth factor of the p30% and cw + p30% groups were lower than those of the Ti group at some time points. Generally, the results indicate that amino-functionalized Ti surfaces can promote Schwann cell adhesion without cytotoxicity, but this modification, in fact, inhibited the expression of the key growth factors GDNF and NGF of Schwann cells.