Abstract
Breast cancer, among the different types of cancer, is one of the most diagnosed cancers
and the leading cause of mortalities amongst women. Factors, including genetic and epigenetic
alterations in tumors, make it resistant to therapies, which results in treatment failures and/or
recurrence. Furthermore, the existing therapies have many unfavorable side effects leading to poor
prognosis and reduced therapeutic outcomes. Photodynamic therapy (PDT) is one of the most
effective cancer therapies with increased selectivity and specificity toward cancer cells. As a result,
the use of gold nanoparticles (AuNP) further improves the effectiveness of PDT by increasing the
drug loading capacity into the cells. In this study, hypericin (Hyp) photosensitizer (PS) was adsorbed
on gold nanoparticles (AuNPs) by sonication to achieve physical adsorption of the PS to AuNP. The
resulting compound was characterized by FTIR, Zeta potential, UV-Vis spectroscopy, and TEM. The
compound was used for the PDT treatment of MCF-7 human breast cancer in vitro. Cellular responses
at 12 h post-PDT at 10 J/cm2 were observed. Cellular morphology, LDH membrane integrity, ATP
luminescence assay, and Annexin V/PI staining were performed. The results demonstrated typical
cell death morphological features while the biochemical responses indicated increased LDH and
decreased ATP levels. In conclusion, this study presents an insight into the application of advanced
PDT in breast cancer cells by inducing cancer cell death in vitro via apoptosis.