Gold and cadmium nanoclusters embedded BSA nanoparticles as two‐color imaging and anti-cancer agent for human breast cancer cell line

This study presents the synthesis and evaluation of a novel multifunctional bimetallic nanocomposite comprising gold (Au) and cadmium (Cd) nanoclusters (NCs) embedded within bovine serum albumin (BSA) nanoparticles for advanced cancer theranostics. The structural and optical properties of the Au-Cd/BSA nanocomposites were comprehensively characterized using photoluminescence and UV–Vis spectroscopy, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, and dynamic light scattering. The distinct red and blue PL emissions of the Au and Cd NCs, respectively, facilitated effective intracellular tracking and diagnostic imaging via confocal laser scanning microscopy. In vitro therapeutic efficacy and cellular mechanisms of action were evaluated using MTT assays and flow cytometry. The novel bimetallic Au-Cd/BSA nanocomposite induces a potent pro-oxidative response in MDA-MB-231 breast cancer cells, driving a significant 5.6-fold increase in intracellular reactive oxygen species (ROS) that serves as the primary trigger for cytotoxicity. This ROS surge effectively activates cell death pathways, culminating in an approximate 20% rise in apoptosis rates alongside notable necrosis and significantly suppressing cancer cell proliferation. Crucially, the BSA-encapsulated nanoplatform exhibits high biocompatibility and preferential toxicity; when tested on non-cancerous adipose mesenchymal stem cells, it maintains > 91% cell viability even at concentrations exceeding the therapeutic threshold for cancer cells. By integrating robust ROS-mediated anti-cancer efficacy and dual-color imaging capabilities, this cost-effective theranostic platform offers a highly promising approach for precision breast cancer nanomedicine.