Modification of the titan surface with photoreactive gelatin to regulate cell attachment

Titan (TiO2) was modified with photoreactive gelatin in order to regulate the attachment of cells. Photoreactive gelatin, which was synthesized by the coupling reaction of gelatin with N-(4-azidobenzoyloxy) succinimide, was immobilized onto the n-octadecyltrimethoxysilane (ODS)-TiO2 or TiO2 surface by ultraviolet irradiation both in the absence and presence of a photo mask. In the absence of a photo mask, the modified titan surface was analyzed by measuring water contact angles and X-ray photoelectron spectroscopy (XPS). The result showed that ODS hydrophobilized the titan surface, and that the immobilization of gelatin affected the surface's hydrophilicity. XPS shows that titan was covered with organic material, including ODS and gelatin. With the photo mask in place, micropatterning of the gelatin was performed. This pattern was confirmed by optical microscopy and time-of-flight secondary ion-mass spectroscopy (TOF-SIMS). Monkey COS-7 epithelial cells were cultured on the unpattern- and pattern-immobilized plate. A significantly higher degree of cell attachment was found on the photoreactive gelatin-immobilized regions than on those that were not immobilized. It was concluded that the cellular pattern on titan was regulated by immobilized photoreactive gelatin.