title: Rose bengal-grafted biodegradable microcapsules: singlet-oxygen generation and cancer-cell incapacitation.
abstract: Rose bengal-grafted chitosan (RB-CHI), synthesized through dehydration between amino and carboxyl functional groups under mild conditions, was coated onto the outer layer of preformed biodegradable microcapsules consisting of sodium alginate and chitosan. The fabricated photosensitive microcapsules were characterized by optical microscopy, scanning electron microscopy, and confocal laser scanning microscopy. The assembled materials maintained intact spherical morphology and thus showed good ability to form thin films. Electron spin resonance spectroscopy allowed direct observation of the generation of singlet oxygen ((1)O(2)) from photosensitive microcapsules under light excitation at about 545 nm. Furthermore, with increasing light radiation, the content of (1)O(2) increased, as detected by a chemical probe. In vitro cellular toxicity assays showed that RB-CHI-coated photosensitive microcapsules exhibit good biocompatibility in darkness and high cytotoxicity after irradiation, and could provide new photoresponsive drug-delivery vehicles.
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, P.R. China.
authors.forename: Xiao-Lei
authors.initials: XL
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Zeng
authors.forename: Yan-Zhen
authors.initials: YZ
authors.lastname: Zheng
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Chen
authors.forename: Xia
authors.initials: X
authors.lastname: Tao
authors.forename: Ling-Xuan
authors.initials: LX
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Teng
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001943:Breast Neoplasms / Q000737:chemistry*; D002214:Capsules; D048271:Chitosan / Q000737:chemistry*; D016503:Drug Delivery Systems; D004578:Electron Spin Resonance Spectroscopy; D005260:Female; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology / Q000379:methods*; D012395:Rose Bengal / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D000464:Alginates; D002214:Capsules; D006603:Hexuronic Acids; D026082:Singlet Oxygen; D012395:Rose Bengal; D020723:Glucuronic Acid; D048271:Chitosan