Phthalocyanine-based probes in alleviating or evading tumour-hypoxia for enhanced photo- and/ sono-mediated therapeutic efficacies

This review discusses the possible methods for improving therapeutic efficacies of phthalocyanine (Pcs) -based therapeutic probes in photo- and sono-dynamic therapies under hypoxic conditions. Herein, the structural design strategies including varying the central metal, position substituents and the effects of adjuvant used in supplementing the therapeutics activities of Pcs or formation of NPs are discussed for cancer therapies in hypoxic conditions. Different mechanisms induced for cell death influenced by the compositions of the Pcs-probes are discussed. The focus mainly highlights the oxygen (O₂) -dependent mechanisms including methods of supplementing tumour microenvironment O₂-concentrations to promote PDT or SDT therapies. Alternatively, O₂-independent mechanisms mainly used to evade hypoxia by stimulating anticancer processes that don't require O₂ to initiate cell death, such as the Fenton reaction or thermal ablation effects.