title: In situ modification of cell-culture scaffolds by photocatalytic decomposition of organosilane monolayers.
abstract: We demonstrate a novel application of TiO2 photocatalysis for modifying the cell affinity of a scaffold surface in a cell-culture environment. An as-deposited octadecyltrichlorosilane self-assembled monolayer (OTS SAM) on TiO2 was found to be hydrophobic and stably adsorbed serum albumins that blocked subsequent adsorption of other proteins and cells. Upon irradiation of ultraviolet (UV) light, OTS molecules were decomposed and became permissive to the adhesion of PC12 cells via adsorption of an extracellular matrix protein, collagen. Optimal UV dose was 200 J cm(-2) for OTS SAM on TiO2. The amount of collagen adsorption decreased when excessive UV light was irradiated, most likely due to the surface being too hydrophilic to support its adsorption. This UV-induced modification required TiO2 to be present under the SAM and hence is a result of TiO2 photocatalysis. The UV irradiation for surface modification can be performed before cell plating or during cell culture. We also demonstrate that poly(ethylene glycol) SAM can also be patterned with this method, indicating that it is applicable to both hydrophobic and hydrophilic SAMs. This method provides a unique tool for fabricating cell microarrays and studying dynamical properties of living cells.
authors.affiliation: Waseda Institute for Advanced Study, Waseda University, 1-6-1 Nishi-waseda, Shinjuku-ku, Tokyo 169-8050, Japan. Nanotechnology Research Center, Waseda University, 513 Waseda Tsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Takanori
authors.initials: T
authors.lastname: Demura
authors.forename: Mayu
authors.initials: M
authors.lastname: Morita
authors.forename: Sho
authors.initials: S
authors.lastname: Kono
authors.forename: Kohei
authors.initials: K
authors.lastname: Sekine
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shinada
authors.forename: Shun
authors.initials: S
authors.lastname: Nakamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanii
mesh_terms: D000818:Animals; D002384:Catalysis / Q000528:radiation effects; D002448:Cell Adhesion; D057927:Hydrophobic and Hydrophilic Interactions; D016716:PC12 Cells; D051381:Rats; D012821:Silanes / Q000737:chemistry*; D013499:Surface Properties; D023822:Tissue Engineering / Q000295:instrumentation*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D012821:Silanes; C061189:octadecyltrichlorosilane