title: A bioaccumulative cyclometalated platinum(II) complex with two-photon-induced emission for live cell imaging.
abstract: The cyclometalated platinum(II) complex [Pt(L)Cl], where HL is a new cyclometalating ligand 2-phenyl-6-(1H-pyrazol-3-yl)pyridine containing C(phenyl), N(pyridyl), and N(pyrazolyl) donor moieties, was found to possess two-photon-induced luminescent properties. The two-photon-absorption cross section of the complex in N,N-dimethylformamide at room temperature was measured to be 20.8 GM. Upon two-photon excitation at 730 nm from a Ti:sapphire laser, bright-green emission was observed. Besides its two-photon-induced luminescent properties, [Pt(L)Cl] was able to be rapidly accumulated in live HeLa and NIH3T3 cells. The two-photon-induced luminescence of the complex was retained after live cell internalization and can be observed by two-photon confocal microscopy. Its bioaccumulation properties enabled time-lapse imaging of the internalization process of the dye into living cells. Cytotoxicity of [Pt(L)Cl] to both tested cell lines was low, according to MTT assays, even at loadings as high as 20 times the dose concentration for imaging for 6 h.
authors.affiliation: Department of Chemistry and Biology, City University of Hong Kong, Tat Chee Avenue, Hong Kong SAR, People's Republic of China.
authors.forename: Chi-Kin
authors.initials: CK
authors.lastname: Koo
authors.forename: Ka-Leung
authors.initials: KL
authors.lastname: Wong
authors.forename: Cornelia Wing-Yin
authors.initials: CW
authors.lastname: Man
authors.forename: Yun-Wah
authors.initials: YW
authors.lastname: Lam
authors.forename: Leo King-Yan
authors.initials: LK
authors.lastname: So
authors.forename: Hoi-Lam
authors.initials: HL
authors.lastname: Tam
authors.forename: Sai-Wah
authors.initials: SW
authors.lastname: Tsao
authors.forename: Kok-Wai
authors.initials: KW
authors.lastname: Cheah
authors.forename: Kai-Chung
authors.initials: KC
authors.lastname: Lau
authors.forename: Yang-Yi
authors.initials: YY
authors.lastname: Yang
authors.forename: Jin-Can
authors.initials: JC
authors.lastname: Chen
authors.forename: Michael Hon-Wah
authors.initials: MH
authors.lastname: Lam
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003500:Cyclization; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D010777:Photochemistry; D017785:Photons; D017671:Platinum Compounds / Q000737:chemistry* / Q000633:toxicity; D013053:Spectrophotometry
chemical_list: D017671:Platinum Compounds