Liposomes Loaded with Activatable Disulfide Bridged Photosensitizer: Towards Targeted and Effective Photodynamic Therapy on Breast Cancer Cells

Abstract

The motivation of the current study is to develop a strategy providing targeted and effective photodynamic therapy (PDT) on breast cancer cells by eliminating the limitations of PDT. For this purpose, a disulfide bridged phthalocyanine with favorable wavelength absorbance that is activatable in cancer cells was synthesized and encapsulated in liposome nanoparticles. The synthesized molecule was characterized using Fourier transform-infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, Matrix-Assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) Mass Spectrometry, Ultraviolet-visible (UV-Vis) spectrophotometry, and particle size analyzer; and the nano-formulation was tested on MCF-7 breast cancer cell line using MTT assay, fluorescence microscopy, and flow cytometry. The results have illustrated that the synthesized disulfide bridged phthalocyanine has a therapeutically active wavelength absorbance value (685 nm), the liposome nanoparticles with the favorable characteristics (average size of 167.6 nm and polydispersity index (PDI) of 0.108) containing the synthesized disulfide bridged phthalocyanine have low dark toxicity, and significant light toxicity (P < 0.001 vs. dark toxicity) characterized with significant apoptosis (p < 0.05 vs. control group). Thus, for further investigations, these results suggest the great potential of the nano-formulation towards targeted and effective PDT on breast cancer cells.