Abstract
The mechanisms of cell death can be predetermined (programmed) or not and
categorized into apoptotic, autophagic and necrotic pathways. The process of Hayflick limits
completes the execution of death-related mechanisms. Reactive oxygen species (ROS)
are associated with oxidative stress and subsequent cytodamage by oxidizing and degrading
cell components. ROS are also involved in immune responses, where they stabilize and
activate both hypoxia-inducible factors and phagocytic effectors. ROS production and
presence enhance cytodamage and photodynamic-induced cell death. Photodynamic cancer
therapy (PDT) uses non-toxic chemotherapeutic agents, photosensitizer (PS), to initiate a
light-dependent and ROS-related cell death. Phthalocyanines (PCs) are third generation and
stable PSs with improved photochemical abilities. They are effective inducers of cell death
in various neoplastic models. The metallated PCs localize in critical cellular organelles and
are better inducers of cell death than other previous generation PSs as they favor mainly
apoptotic cell death events.