Improved photodynamic anticancer activity and mechanisms of a promising zinc(II) phthalocyanine-quinoline conjugate photosensitizer and .

Since the discovery of photodynamic therapy, scientists have constantly been searching for more effective and ideal photosensitizers (PSs). As part of our ongoing interest in the development of more potent photosensitizers, quinoline-8-yloxy-substituted zinc(II) phthalocyanine () has been identified as a promising photosensitizers in tumor cells. This study aims to explore the photodynamic mechanism and photodynamic efficacy of , and further evaluate its potential in clinical photodynamic therapy application. The single crystal structure of enables the easy control of clinical quality standards. In comparison with Photofrin, exhibits considerably higher anticancer activity by dual dose-related mechanisms (antiproliferative and apoptosis). In addition, the results demonstrate that exhibits significant tumor regression with less skin photosensitivity by both direct killing and apoptosis anticancer mechanisms. In conclusion, can be considered to be a promising ideal PS for clinical application owing to its defined chemical structure without phthalocyanine isomerization, good absorption of tissue-penetrating red light, improved photodynamic therapy efficacy, and reduced skin phototoxicity.