Beyond the Conventional Photodynamic Therapy by Water‐Soluble Phthalocyanines

Abstract Compared to the classical chemotherapy applications, PDT applications are based on a non‐toxic compound that can be specifically activated by shining a certain wavelength of light. Constitituvely active chemotherapy drug agents lead to detrimental and unwanted side effects that halt the normal life standards of the cancer patients. Localized and controlled activation of the drug agents by PDT applications aims to overcome the side effects associated with the treatment. In our study we synthesized a unique set of phthalocyanine molecules that are water soluble to make them biocompatible. Moreover, these compounds anti‐cancer activities were measured from multiple angles. Anti‐cancer PDT activities of the derivatives were studied by testing their effects on the cell proliferation, apoptosis and cell cycle progression. Moreover, these derivatives anti‐metastatic, anti‐angiogenic and immunomodulatory photodynamic activities were comprehensively studied by focusing on the intracellular signaling pathways that may play important roles in carcinogenesis, angiogenesis, metastasis and immune reactions. For the first time to our knowledge we are presenting data beyond the classical or canonical PDT applications in which generation of the reactive oxygen species (ROS) is explained as the main mechanism of the action for the PDT applications. Our results suggest that non‐canonical PDT activity can be observed independent of the ROS generation efficiencies probably by affecting the intracellular signaling pathways. These novel set of phthalocyanine derivatives may find applications against colon, lung, breast and prostate cancer.