In-Vitro Cytotoxicity and Biological Potential of Mn-Doped Ag₂S Nanoparticles in Breast Cancer Cell Lines

The integration of manganese (Mn) into silver sulfide (Ag₂S) nanoparticles offers a promising avenue for enhancing their physicochemical properties and biological activity for breast cancer applications. This study investigates the synthesis, characterization, and cytotoxic effects of Mn-doped Ag₂S nanoparticles on four breast cancer cell lines representing distinct subtypes: luminal A (MCF-7), luminal B (BT-474), triple-negative (MDA-MB-231), and HER2-positive (SK-BR-3). Using a sonochemical method, Mn-doped nanoparticles with controlled sizes and compositions were obtained, and their properties were assessed through TEM, FTIR, UV–Vis, and XRF analyses. Results revealed that Mn doping significantly influenced particle size, zeta potential, and quantum confinement effects, leading to enhanced reactivity. Biological evaluations indicated dose- and subtype-dependent cytotoxicity. Mn doping at 1% w/w demonstrated a balance between cytotoxicity and proliferative effects at low concentrations, particularly in luminal subtypes, while 5% w/w Mn doping resulted in pronounced cytotoxicity, especially in aggressive subtypes such as MDA-MB-231 and SK-BR-3. The findings highlight the importance of Ag2S nanoparticle composition and dose optimization for minimizing adverse effects while maximizing therapeutic potential.