Investigating the cytotoxicity of Aluminum-Doped zinc oxide nanoparticles in normal versus cancerous breast cells

This study investigates the concentration-dependent cytotoxicity of aluminum-doped zinc oxide nanoparticles on breast cancer (MDA-MB-231) and normal mammary epithelial cells (MCF-10 A). Pure and Al-doped ZnO nanoparticles (Al-ZnO NPs, Zn_1-xAl_xO, x = 0.0: ZnO, 0.01: ZA1, 0.03: ZA3, and 0.05: ZA5) were synthesized by the gelatin-based sol-gel method. The properties of the pure and Al-doped ZnO nanoparticles were investigated by X-ray diffraction (XRD), field emission electron microscopy (FESEM), and ultra-violate-visible (UV-vis) spectroscopy. Using an indirect viability assay, the prepared samples were evaluated across a 5-500 µg/mL range, with IC50 (half-maximal inhibitory concentration) as the primary metric. Results demonstrated enhanced toxicity toward cancer cells, with IC50 values for ZnO, ZA1, ZA3, and ZA5 at (225, 100, 80, and 60 µg/mL) compared to normal cells (500 µg/mL, in the experimental range), respectively. Progressive doping (ZA1 → ZA5) improved cancer cell targeting by synergistically enhancing ROS generation and reducing normal cell susceptibility. These findings underscore Al-ZnO NPs as tunable, selective therapeutic agents, leveraging dopant-driven redox modulation to optimize oncological efficacy while sparing healthy tissue.