Copper Nanoparticles at Optimized Concentrations Exhibit Minimal Intrinsic Biological Effects in Hepatocellular Carcinoma Cells

Background: Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and remains a major cause of cancer-related morbidity and mortality worldwide; recent advancements in nanomedicine provide promising prospects for its treatment. Studies in the field of nanomedicine in recent years emphasize that copper nanoparticles (CuNPs) can be used as significant drug carriers in liver cancer. However, the excessive variability in their cytotoxic profiles restricts the safe use of these particles as drug delivery vehicles. Our study aimed to determine concentration ranges of CuNPs with minimal detectable effects on cellular viability and homeostasis in a liver cancer cell model. Methods: The cytotoxic potential of ~50 nm CuNPs synthesized via a chemical reduction method (NaBH4/PVP) was evaluated in well-differentiated Huh7 and poorly differentiated Mahlavu cell lines. Results: SEM analysis revealed CuNPs with particle sizes of approximately 42–55 nm (~50 nm), while DLS measurements showed hydrodynamic diameters of 60–80 nm. Cell viability assays demonstrated that CuNPs reduced cell viability in Huh7 and Mahlavu cells in a dose- and time-dependent manner. Optimized concentrations at which cell viability was not significantly affected were defined as 0.04 µg/mL for Huh7 and 0.1 µg/mL for Mahlavu. At these specific doses, colony-forming capacity was not significantly affected, apoptosis was not induced in HCC cells, and cellular morphology remained preserved. Furthermore, pAKT(Ser473)/AKT signaling was not significantly altered in Mahlavu cells at the optimized concentration, whereas pAKT(Ser473) was not reliably detectable in Huh7 cells under the experimental conditions. The levels of the pro-apoptotic protein cleaved caspase-3 were not significantly altered at the optimized concentrations. Conclusions: Our findings indicate that, at optimized concentrations, CuNPs exhibit minimal intrinsic biological effects on HCC cells, supporting their further investigation as potential drug-delivery platforms for HCC.