Chemotoxic and phototoxic effects of liposomal co-delivery of green synthesized silver nanoparticles and ZnPcS₄ for enhanced photodynamic therapy in MCF-7 breast cancer cells: An in vitro study

Breast cancer remains a significant challenge in oncology, despite notable advances in treatment methods. Traditional therapies such as surgery, chemotherapy, radiation, and hormonal treatments have long been used to manage breast cancer. However, often patients experience treatment failure, resulting in disease recurrence and progression. Therefore, this study explores the therapeutic potential of green-synthesized silver nanoparticles (AgNPs), using the root methanol (MeOH) extract of the African medicinal plant Dicoma anomala (D. anomala) as a reducing agent, to combat breast cancer. AgNPs were synthesized using a bottom-up approach and later modified with liposomes (Lip) loaded with the photosensitizer zinc phthalocyanine tetrasulfonate (Lip@ZnPcS₄) through the thin film hydration method. Prior to in vitro cell culture studies, UV–Vis spectroscopy was used to study the in vitro drug release kinetics of nanoparticles (NPs) at pH 5.8 and 7.4 respectively. After a 24 h treatment period, MCF-7 breast cancer cells were evaluated for cell cytotoxicity using lactate dehydrogenase Cyto-Tox96® Non-Radioactive Cytotoxicity Assay Kit LDH and cell viability using the CellTiter-Glo® ATP luminescence assay kit. Cell death studies were analyzed using an inverted light microscope for morphological changes, fluorescence microscopy for reactive oxygen species (ROS) detection and Live/Dead cell viability, human p53 protein analysis using enzyme-linked immunosorbent assay (ELISA), apoptotic and anti-apoptotic protein analysis by immunofluorescence, and gene expression analysis using real-time reverse transcription polymerase chain reaction (RT-PCR) assay. The experiments were conducted in quadruplicate (n = 4), and the results were analyzed using IBM SPSS statistical software version 27, with a 95 % confidence interval. The synthesized NPs and nanocomplexes, including AgNPs, AgNPs-Lip, Lip@ZnPcS₄, and AgNPs-Lip@ZnPcS₄, demonstrated significant cytotoxicity and therapeutic potential against MCF-7 breast cancer cells. Notably, apoptosis was induced, primarily through the activation of the intrinsic pathway. Given the difficult prognosis associated with breast cancer, these findings highlight the promise of liposomal nanoformulations (NFs) in cancer photodynamic therapy (PDT), supporting further investigation in in vivo settings.