van Lier J E, Spikes J D
MRC Group in the Radiation Sciences, Faculty of Medicine, University of Sherbrooke, Quebec, Canada.
Ciba Found Symp. 1989;146:17-26; discussion 26-32. doi: 10.1002/9780470513842.ch3.
Phthalocyanines (Pcs) and naphthalocyanines (Ncs) are being extensively studied as photosensitizers for photodynamic therapy (PDT) of cancer. They strongly absorb clinically useful red light, with maxima around 670 nm and 770 nm respectively. Chelated with appropriate diamagnetic metal ions, they exhibit high triplet yields and long triplet lifetimes. Energy transfer from the triplet dye to ground-state oxygen to yield singlet oxygen appears to be the main photosensitizing pathway in biological systems. Underivatized Pcs and Ncs can be incorporated in liposomes for in vivo administration. Sulphonation renders the dyes water soluble but also enhances dimerization to yield photochemically inactive aggregates. Tumour retention and cell membrane penetration of the dyes are strongly affected by the polarity of the macrocycle as well as the nature of the central metal ion and axial ligands. Among the sulphonated dyes, amphiphilic mono- and disulphonated derivatives exhibit particularly good cell membrane-penetrating properties, although the more highly sulphonated dyes show better tumour retention in vivo. At least in vitro, Pc dyes are more photoactive than the corresponding Nc dyes, which probably reflects the lower photostability of the latter.
酞菁（Pcs）和萘酞菁（Ncs）作为癌症光动力疗法（PDT）的光敏剂正受到广泛研究。它们强烈吸收临床上有用的红光，最大吸收波长分别约为670纳米和770纳米。与适当的抗磁性金属离子螯合后，它们表现出高三重态产率和长三重态寿命。三重态染料向基态氧的能量转移以产生单线态氧似乎是生物系统中的主要光敏途径。未衍生化的Pcs和Ncs可被包封在脂质体中用于体内给药。磺化使染料具有水溶性，但也增强了二聚化，从而产生光化学惰性聚集体。染料的肿瘤滞留和细胞膜穿透受到大环极性以及中心金属离子和轴向配体性质的强烈影响。在磺化染料中，两亲性单磺化和二磺化衍生物表现出特别好的细胞膜穿透性能，尽管磺化程度更高的染料在体内显示出更好的肿瘤滞留性。至少在体外，酞菁染料比相应的萘酞菁染料具有更高的光活性，这可能反映了后者较低的光稳定性。
