Benzalkonium Chloride-Coated Iron Oxide Nanoparticles: Cytotoxic Potential on Murine Leydig Cells (TM3)

This study presents a novel nanocomplex, Mag-Bc, combining magnetite (Mag) and benzalkonium chloride (Bc). The objective was to evaluate the cytotoxic potential of Mag-Bc across three cell lines (TM3, VERO, and AML-12) and to assess its antiandrogenic effects specifically on TM3 cells. Physicochemical characterization confirmed the formation of partially oxidized magnetite and successful Bc coating, which conferred a positive charge to the nanoparticles. Viability assays on TM3 cells demonstrated no reduction below 70% at any dose or exposure time. Cellular internalization studies revealed efficient uptake of both coated and uncoated nanoparticles, indicating that the Bc coating did not impair cellular internalization. The nanocomplex exhibited intermediate superoxide anion production, maintaining levels comparable to control groups and demonstrating superior biocompatibility compared to magnetite and benzalkonium chloride alone. Testosterone levels remained unchanged following exposure to the Bc-coated nanoparticles. Collectively, these findings demonstrate that the Mag-Bc nanocomplex exhibits enhanced biocompatibility, characterized by a maintained cell viability, preserved cellular internalization capacity, reduced oxidative stress, and unchanged endocrine function. In contrast, cell growth kinetics of TM3 cells exposed to Bc-coated nanoparticles demonstrated reduced proliferation between days 3 and 8 compared with controls, suggesting potential time-dependent effects. The growth inhibition of Leydig cells induced by the nanocomplex may have implications for applications requiring suppression of testicular cell proliferation or for the development of nanoparticle-based therapeutic strategies targeting cell growth arrest.