Multifunctional NiO-curcumin nanocomposite-loaded chitosan-alginate scaffolds for enhanced bone tissue regeneration and antibacterial activity

Regenerating infected bone tissue requires advanced biomaterials that integrate mechanical strength, antibacterial properties, and biomineralization potential. Here, we developed bioactive chitosan-alginate (CA) scaffolds reinforced with nickel oxide-curcumin (NiO-Cur) nanocomposites (CANC) using sol-gel synthesis, chemical crosslinking, and freeze-drying. The incorporation of NiO-Cur nanocomposites enhanced the scaffolds structural and functional properties, as confirmed by ATR-FTIR, XRD, FE-SEM, and EDAX analyses. The scaffolds exhibited better compressive strength (406.1 ± 3.79 KPa), high porosity (85.72 ± 1.01 % to 91.08 ± 1.19 %) with interconnected honeycomb-like pores (114–132 μm), facilitating nutrient diffusion and cellular infiltration. Enhanced compressive strength and rheological properties (G′ > G′′) demonstrated their ability to dissipate shear stress and withstand dynamic loads, critical for bone tissue engineering. Cur release profiles for CANC1, CANC2, and CANC3 scaffolds after 72 h were 72.05 %, 78.32 %, and 83.95 %, respectively. Additionally, CANC scaffolds also displayed superior hydrophilicity, promoting swelling and controlled degradation under physiological conditions. In vitro biomineralization studies revealed dense apatite formation within 14 days in simulated body fluid, favouring osteoconductive potential. Additionally, CANC scaffolds exhibited significant antibacterial activity with zone of inhibition value of (10.78 ± 0.23 mm) against Staphylococcus aureus and (8.05 ± 0.2 mm) Escherichia coli, suggesting efficacy in preventing post-surgical infections. The synergistic interaction between NiO-Cur nanocomposites and the CA matrix improved physicochemical, mechanical, and rheological stability, alongside enhanced antibacterial efficacy and apatite-forming potential. Preclinical studies could further validate the potential of CANC scaffolds to accelerate bone healing, reduce recovery time in infected bone injuries, and advance tissue regeneration applications.