Antioxidant and biocompatible CuO-starch/PVA nanoscaffolds via ultrasonic green synthesis using Turbinaria conoides (brown marine macroalgae)

• Green synthesis of CuO NPs using Turbinaria conoides marine algae extract. • CuO NPs embedded in starch/PVA nanoscaffolds via electrospinning. • Nanoscaffolds show excellent biocompatibility and thermal stability. • Enhanced antioxidant activity due to CuO-polymer synergistic effects. • Promising platform for wound healing and oxidative stress therapy. This study reports, sustainable and biogenic synthesis of copper oxide nanoparticles (CuO NPs) using ultrasonic-assisted Turbinaria conoides aqueous extract and their incorporation into starch/polyvinyl alcohol (PVA) electrospun nanoscaffolds for biomedical applications. The biosynthesized CuO NPs exhibited characteristic surface plasmon resonance (SPR) at 270–300 nm and a monoclinic crystalline structure, as confirmed by UV–Vis spectroscopy and XRD analysis. FTIR spectra revealed successful CuO NPs-polymer interactions, while SEM imaging showed uniform nanofibers with well-dispersed CuO NPs. The nanocomposite scaffolds demonstrated enhanced thermal stability, with decomposition onset at 326.78 °C, and excellent biocompatibility (cell viability ≥ 100 % in MTT assays). The CuO-loaded scaffolds exhibited higher antioxidant activity (IC 50 ∼ 18 µg/mL) compared to bare NPs (IC 50 ∼ 28 µg/mL). Although zeta potential measurements indicated moderate colloidal stability (−11.39 mV), the overall results highlight the potential of these nanocomposite scaffolds for tissue engineering and therapeutic applications, particularly in wound healing and oxidative stress management. This green synthesis approach offers a sustainable platform for developing functional biomaterials.