Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Santiago, Chile.
Photochem Photobiol Sci. 2011 Apr;10(4):507-14. doi: 10.1039/c0pp00289e. Epub 2010 Dec 13.
Phthalocyanines are macrocyclic compounds that can be employed as photosensitizers in the treatment of various infections and diseases, as well as in photodynamic therapy. Nevertheless, a disadvantage for the clinical application of these compounds is their strong tendency to form oligomers (especially dimers), a phenomenon that reduces their efficiency as photosensitizers. In the present contribution, we have studied the photophysical and photochemical properties of ZnPc and ZnF(16)Pc in an organic solvent (THF) and liposomal formulations (DMPC, DPPC and DSPC). Our results show that dye incorporation into liposomes decreases its aggregation degree, as revealed by absorption spectra, triplet quantum yield, and singlet oxygen quantum yield measurements. Additionally, we studied the photodynamic activity of both phthalocyanines in liposomal formulation on human cervical carcinoma (HeLa) cells. For ZnF(16)Pc the photophysical behavior and phototoxicity in vitro correlate with the aggregation degree. The dimers are not photoactive and the photochemistry of ZnF(16)Pc depends of the fraction present as monomer. On the other hand, ZnPc aggregation is minimal and its photophysical and photochemical properties are similar in the three liposomes studied. Nevertheless, its phototoxicity in vitro is liposome dependent.
酞菁是一种大环化合物，可用作治疗各种感染和疾病以及光动力疗法的光敏剂。然而，这些化合物在临床应用中的一个缺点是它们强烈倾向于形成低聚物（尤其是二聚体），这种现象降低了它们作为光敏剂的效率。在本研究中，我们研究了 ZnPc 和 ZnF(16)Pc 在有机溶剂（THF）和脂质体配方（DMPC、DPPC 和 DSPC）中的光物理和光化学性质。我们的结果表明，染料掺入脂质体中会降低其聚集度，这可以通过吸收光谱、三重态量子产率和单线态氧量子产率的测量来证实。此外，我们还研究了这两种酞菁在脂质体制剂中对人宫颈癌（HeLa）细胞的光动力活性。对于 ZnF(16)Pc，其光物理行为和体外光毒性与聚集度有关。二聚体没有光活性，ZnF(16)Pc 的光化学反应取决于其单体的比例。另一方面，ZnPc 的聚集度最小，其光物理和光化学性质在研究的三种脂质体中相似。然而，其体外光毒性取决于脂质体。
