Enhanced mitochondria destruction on MCF-7 and HeLa cell lines in vitro using triphenyl-phosphonium-labelled phthalocyanines in ultrasound-assisted photodynamic therapy activity

This work reports on the reactive oxygen species (ROS) generation and the therapeutic activities of new triphenyl-phosphonium-labelled phthalocyanines (Pcs), the 2,9,16,23- tetrakis ( N- ( N -butyl-4-triphenyl-phosphonium)- pyridine-4-yloxy) Zn(II) Pc ( 3 ) and 2,9,16,23- tetrakis -( N- ( N -butyl-4-triphenyl-phosphonium)-morpholino) Zn(II) Pc ( 4 ) upon exposure to light, ultrasound and the combination of light and ultrasound. Two types of ROS were detected: the singlet oxygen ( 1 O 2 ) and hydroxyl radicals. For light irradiations, only the 1 O 2 was detected. An increase in the ROS generation was observed for samples treated with the combination of light and ultrasound compared to the light and ultrasound mono-treatments. The in vitro anticancer activity through photodynamic (PDT) and sonodynamic (SDT) therapy for the Pcs were also determined and compared to the photo-sonodynamic combination therapy (PSDT). The two cancer cell lines used for the in vitro studies included the Michigan Cancer Foundation-7 (MCF-7) breast cancer and Henrietta Lacks (HeLa) cervical cancer cell lines. The SDT treatments showed improved therapeutic efficacy on the cancer cells for both the Pcs compared to PDT. PSDT showed better therapeutic efficacy compared to both the PDT and SDT mono-treatments. • Triphenyl-phosphonium-labelled Zn phthalocyanines are synthesized. • Their photodynamic (PDT) and sonodynamic (SDT) against MCF-7 and HeLa cancer cells are presented. • The SDT treatments showed improved therapeutic efficacy on the cancer cells compared to PDT. • Combination PDT/SDT showed better therapeutic efficacy compared mono-treatments.