Surface engineering of Ti–O films by photochemical immobilization of gelatin

Crystalline Ti–O films were prepared by unbalanced magnetron sputtering and the structure was confirmed by XRD. An organic layer of 3-aminopropylphosphonic acid (APP) was first introduced on the Ti–O films by self-assembling. The stability of the APP on Ti–O films was confirmed by XPS and FTIR analysis. Simultaneously, azido group was introduced in gelatin molecule to act as photoreactive point. The derivated gelatin was spin-coated onto the self-assembled layer and immobilized by UV irradiating. Chemical patterned surface was obtained by using a photomask when irradiating and confirmed by sirius red staining and surface profile analysis. Measured by surface profilometer, the thickness of the immobilized gelatin was about 5–20 nm. The adhering of human endothelial EVC304 cells on APP modified surface was enhanced in the cell culture test. Moreover, the adherence and growth of cells were prior on gelatin-immobilized region visually seen on the patterned surface. This result indicated gelatin-immobilized Ti–O surface can serve as a biocompatible biomaterial for endothelialization.