A self-assembling luminescent lanthanide molecular nanoparticle with potential for livecell imaging

作者:Yang, Xiaoping*; Wang, Shiqing; Zhang, Yali; Liang, Guang*; Zhu, Ting; Zhang, Lijie; Huang, Shaoming*; Schipper, Desmond; Jones, Richard A.*
来源:Chemical Science, 2018, 9(20): 4630-4637.
DOI:10.1039/c8sc00650d

摘要

Four luminescent 32-metal Cd-Tb nanoclusters, [Tb8Cd24(L-1)(12)(OAc)(48)] (1), [Tb8Cd24(L-2)(12)(OAc)(48)] (2), [Tb8Cd24(L-3)(12)(OAc)(48)] (3) and [Tb8Cd24(L-2)(12)(1,4-BDC)(4)(OAc)(38)(OH)(2)] (4), were constructed from three specially designed chain-like Schiff base ligands H2L1-3 with flexible carbon-carbon backbones containing 5, 6 and 10 methylene units, respectively. The clusters exhibit drum-like structures and can be imaged using transmission electron microscopy (TEM). In addition to the Schiff base ligands (the primary energy transfer donors), four 1,4-BDC bridging units were successfully introduced into the structure of 4. In addition to providing increased structural stability, the 1,4-BDC units act as secondary energy transfer donors providing extra energy for lanthanide luminescence, which results in improved luminescence properties when compared to those of the related Cd-Ln nanoclusters without 1,4-BDC units. In vitro investigations on 4 with SGC and PANC cancer cells revealed an accumulation of the molecular nanoparticles in the cells, as confirmed by confocal microscopy. The cytotoxicity of 4 toward the SGC and PANC cells is moderate (IC50 values of 4 lie in the range of 15-60 M). ICP-MS analysis reveals that cellular uptakes of 4 in 1000 SGC and PANC cells after treatment for 3 hours are 0.0094 pmol and 0.015 pmol, respectively.