Antioxidant Properties and In Vitro Biocompatibility of Monodispersed Cuprous Oxide (Cu₂O) Nanoparticles

The increasing prevalence of oxidative stress-related disorders underscores the need for safe and effective nanomaterials with strong antioxidant properties and good biocompatibility. In this study, copper oxide nanoparticles (Cu₂O NPs) were successfully prepared by a simple chemical method and evaluated for their biocompatibility and antioxidant properties. The prepared NPs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS). Results showed that Cu₂O NPs are monodispersed with a spherical shape and an average diameter of 88 ± 6 nm. In vitro biocompatibility studies on 3T3 murine fibroblasts revealed that Cu₂O NPs exhibited no significant cytotoxic effects at lower concentrations (0.07-7.15 μg/mL), indicating their potential use in biomedical applications within this range. Increasing the concentration from 7.12 μg/mL to 100 μg/mL resulted in a pronounced reduction in cell viability and oxidative stress induction, as assessed using the Almar Blue test and the intracellular CM-H₂CDFDA probe, respectively. DPPH scavenging and TMB kinetic assays demonstrated significant antioxidant activity (IC₅₀ = 7.05 μg/mL) and catalytic properties of Cu₂O NPs. This study provides a novel and systematic correlation between physicochemical properties, catalytic activity, and biological response, identifying a potential range of biocompatibility for the biomedical application of Cu₂O nanoparticles.