Synthesis and Characterization of Brucine Gold Nanoparticles for Targeted Breast Cancer Therapy: Mechanistic Insights into Apoptosis and Antioxidant Disruption in MCF-7 Cells

Globally, breast cancer continues to be the leading type of cancer affecting women, with rising mortality rates projected by 2030. This highlights the importance of developing new, affordable treatments, like drug delivery systems that use nanoparticles. Gold nanoparticles (AuNPs), including their exceptional optical and physical attributes, make them an attractive vehicle for targeted treatment, allowing for accurate and focused delivery of medication directly to cancerous cells while reducing harmful side effect. This study focuses on the synthesis and characterization of brucine-gold nanoparticles (BRU-AuNPs) for targeted breast cancer therapy by evaluating their antioxidant and apoptotic mechanism. BRU-AuNPs were synthesized and characterized (UV-Vis spectroscopy, Fourier transform infrared [FTIR], scanning electron microscopy [SEM], x-ray diffraction [XRD], dynamic light scattering [DLS], and zeta potential) to confirm successful synthesis, size, and stability. In vitro studies were assessed using MCF-7 breast cancer cell lines to evaluate cell cytotoxicity, antioxidant balance, reactive oxygen species (ROS) generation, mitochondrial membrane potential, apoptosis induction, cell migration, and pro-apoptotic gene expression. Characterization results confirmed the successful synthesis of BRU-AuNPs with an average crystal size of 85.40 nm and stable surface charge. Results demonstrated that BRU-AuNPs reduced MCF-7 cell viability in a dose-dependent manner, with an IC₅₀ value of 11.47 µg/mL. Treatment with BRU-AuNPs altered the antioxidant balance, increased ROS generation, depolarized mitochondrial membranes, and induced apoptosis. Additionally, BRU-AuNPs inhibited cell migration and upregulated pro-apoptotic gene expression. The synthesized BRU-AuNPs exhibit potential as a highly effective targeted delivery system for breast cancer treatment. Their ability to directly deliver BRU to tumor cells while reducing side effects and enhancing therapeutic efficacy underscores their promise in advancing breast cancer therapy. Further studies are warranted to explore their clinical potential and optimize therapeutic outcomes.