A phthalocyanine-based self-assembled nanophotosensitizer for efficient in vivo photodynamic anticancer therapy.

To develop highly efficient photosensitizers for photodynamic therapy, herein a zinc(II) phthalocyanine-folate conjugate (PcN - FA) used to construct an activatable nanophotosensitizer (NanoPcN - FA) through a facile self-assembly. The self-assembled nanophotosensitizer (NanoPcN) without folate-modification was used as a negative control. After self-assembly, the photoactivities of NanoPcN - FA was quenched. The in vitro studies showed that NanoPcN - FA could be taken in by folate-receptor (FR)-positive SKOV3 cells and activated in the cells. It also exhibited slightly higher photocytotoxicity against SKOV3 cells than NanoPcN. Moreover, the competitive assay confirmed that the cellular uptake of NanoPcN - FA was through a FR-mediated process. Finally, the in vivo results indicated that NanoPcN - FA could target tumor tissue of S180 rat ascitic tumor-bearing mice due to the folic acid (FA) ligand, leading to a highly efficient antitumor photodynamic efficacy with the tumor inhibition rate of 95%. [Display omitted] • A phthalocyanine-folate conjugate self-assembled into activatable nanophotosensitizer. • The photoactivities of the phthalocyanine were quenched in the nanophotosensitizer. • It was taken in by folate receptor (FR)-positive cells through a FR-mediated pathway. • The quenched photoactivities could be activated in FR-positive cells and tumor tissues. • It had efficient tumor targeting and in vivo photodynamic anticancer efficacy. [ABSTRACT FROM AUTHOR]