Oxytetracycline loading onto Cu-CuO/Cu₂O nanocomposites (NCs): structural characterization and enhanced antimicrobial...

In this study, the chemical reduction technique was utilized to create a three-phase nanocomposite system including metallic copper (Cu⁰), cupric oxide (CuO, Cu²⁺), and cuprous oxide (Cu₂O, Cu⁺) inside a single matrix in one step. The Cu-CuO/Cu₂O nanocomposite NCs were analyzed by XRD, SEM, EDX, and FT-IR to study the structural and chemical properties. The XRD analysis elucidated the crystallinity of the Cu-CuO/Cu₂O NPs, revealing multiple patterns of copper, including Cu, CuO, and Cu₂O, with a mean particle size of 21.2 nm. SEM + EDX show the morphology of the Cu-CuO/Cu₂O NCs with an average grain diameter ≈30 nm and a distribution range of 5-53 nm. The SEM images proved loading of the Cu-CuO/Cu₂O NCs with the Oxytetracycline (OTC) drug. Oxytetracycline (OTC) was delivered with the Cu-CuO/Cu₂O NCs for developing resistance against microbial pathogens. The results showed that the minimum inhibitory concentration of the OTC@Cu-CuO/Cu₂O NCs against the Gram-negative bacteria E. coli was 62 µg mL^-1 with an IC₅₀ of 29.4 µg mL^-1. While the minimum inhibitory concentration of OTC@Cu-CuO/Cu₂O NPs against the Gram-positive bacteria Staph. aureus was 62 µg mL^-1 with an IC₅₀ of 21.8 µg mL^-1. Additionally, the minimum inhibitory concentration of OTC@Cu-CuO/Cu₂O NCs versus Candida albicans was 250 µg mL^-1, with an IC₅₀ of 37.5 µg mL^-1. It is therefore found that this study could be used in the formulation of nano@drug conjugates that serve as antimicrobial agents in various fields of medical and pharmaceutical research.