title: Confined Singlet Oxygen in Mesoporous Silica Nanoparticles: Selective Photochemical Oxidation of Small Molecules in Living Cells.
abstract: Chemical conversion of specific bioactive molecules by external stimuli in living cells is a powerful noninvasive tool for clarification of biomolecular interactions and to control cellular functions. However, in chaotic biological environments, it has been difficult to induce arbitrary photochemical reactions on specific molecules because of their poor molecular selectivity. Here we report a selective and nontoxic photochemical reaction system utilizing photoactivated mesoporous silica nanoparticles to control biological functions. Methylene blue modification within nanoparticle pores for photosensitization produced singlet oxygen confined to the pore that could mediate selective oxidation of small molecules without any damage to living cells. This intracellular photochemical system produced bioactive molecules in situ and remotely controlled the cell cycle phase. We also confirmed that this photoreaction could be applied to control cell cycle phase in tumor tissue transplanted in mice. The cell cycle phase in the cells in mice, to which our system was administered, was arrested at the G2/M phase upon photoirradiation. We demonstrate a simple and promising method for the exogenous conversion of an intracellular biomolecule to another functional compound.
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Aoi
authors.initials: A
authors.lastname: Son
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Yui
authors.initials: Y
authors.lastname: Umehara
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto, 615-8510, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University , 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, 252-5258, Japan.
authors.forename: Ryohsuke
authors.initials: R
authors.lastname: Kurihara
authors.affiliation: Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University , 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, 252-5258, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Ikemura
authors.affiliation: Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University , 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, 252-5258, Japan.
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Tanabe
mesh_terms: D000818:Animals; D051379:Mice; D053758:Nanoparticles; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D012822:Silicon Dioxide; D026082:Singlet Oxygen / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D026082:Singlet Oxygen; D012822:Silicon Dioxide