A bioaccumulative cyclometalated platinum(II) complex with two-photon-induced emission for live cell imaging.
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.
Koo
Chi-Kin
CK
Department of Chemistry and Biology, City University of Hong Kong, Tat Chee Avenue, Hong Kong SAR, People's Republic of China.
Wong
Ka-Leung
KL
Man
Cornelia Wing-Yin
CW
Lam
Yun-Wah
YW
So
Leo King-Yan
LK
Tam
Hoi-Lam
HL
Tsao
Sai-Wah
SW
Cheah
Kok-Wai
KW
Lau
Kai-Chung
KC
Yang
Yang-Yi
YY
Chen
Jin-Can
JC
Lam
Michael Hon-Wah
MH
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
D017671:Platinum Compounds