Two-photon induced luminescence, singlet oxygen generation, cellular uptake and photocytotoxic properties of amphiphilic Ru(ii) polypyridyl–porphyrin conjugates as potential bifunctional photodynamic therapeutic agents
作者:JingXiang Zhang、Ka-Leung Wong、Wai-Kwok Wong、Nai-Ki Mak、Daniel W. J. Kwong、Hoi-Lam Tam
DOI:10.1039/c1ob05415e
日期:——
Two Ru(II) polypyridyl-porphyrin and Zn(II) porphyrin conjugates (Ru-L and Ru-Zn-L) have been synthesized and their photophysical properties studied. The two conjugates, which contained a hydrophobic tetraphenylporphyrin L conjugated via an acetylide linker at its β-position with a hydrophilic Ru(II) polypyridyl complex, showed high singlet oxygen quantum yields (>70%) and substantial two-photon absorption cross-sections (â¼500 GM). Ru-L gave strong emissions at â¼660 and â¼733 nm through linear or two-photon excitation. Solvatochromism was observed in the fluorescence spectra of Ru-L and Ru-Zn-L, where in less polar solvents (i.e., toluene and dichloromethane) their fluorescence emissions became slightly blue-shifted with a 3-fold reduction in intensity relative to those observed in polar solvents (i.e., acetonitrile and methanol). Cell-based studies of these complex conjugates were conducted using human nasopharyngeal carcinoma HK-1 and cervical carcinoma HeLa cells on which Ru-L showed rapid cellular uptake, low dark-cytotoxicity, and high photo-cytotoxicity. Furthermore, Ru-L can be excited and emits in the âbiological windowâ in vitro, making it a potential potent new generation photodynamic therapeutic agent capable of singlet oxygen generation and in vitro near-infrared emission.
合成了两种Ru(II)多吡啶-卟啉和Zn(II)卟啉的共轭物(Ru-L和Ru-Zn-L),并研究了它们的光物理性质。这两种共轭物包含一个疏水性的四苯基卟啉L,通过乙炔连接基团在其β位与亲水性的Ru(II)多吡啶复合物共轭,显示出高达70%以上的单重态氧量子产率和显著的双光子吸收截面(约500 GM)。Ru-L在约660和733 nm处通过线性或双光子激发产生强烈的发光。在Ru-L和Ru-Zn-L的荧光光谱中观察到溶剂色散现象,在极性较小的溶剂(如甲苯和二氯甲烷)中,它们的荧光发射略微蓝移,且强度相对极性溶剂(如乙腈和甲醇)降低了3倍。对这些复合物的细胞研究使用了人类鼻咽癌HK-1细胞和宫颈癌HeLa细胞,Ru-L表现出快速的细胞摄取、低暗毒性和高光毒性。此外,Ru-L可以在“生物窗口”内激发并发光,显示出其作为新一代光动力治疗剂的潜力,能够产生单重态氧并在体外进行近红外发光。