Electroconductive and biodegradable scaffold based on alginate/polyaniline hydrogel loaded with green synthesized magnesium oxide nanoparticles for bone regeneration.

Bone fractures are increasing globally, and the limitations of traditional grafts have encouraged the development of advanced biomaterial-based strategies for bone repair. In this study, we developed an injectable alginate/polyaniline (Alg/PANI) hydrogel containing green-synthesized magnesium oxide nanoparticles (MgONPs). The Alg/PANI/NPs scaffold exhibited favorable cytocompatibility and bioactivity, enhancing osteoblast-like cell viability/proliferation to 115.7% by day 3 and reducing hemolysis to 4.67%, indicating improved hemocompatibility. In addition, the scaffold was associated with macrophage polarization toward the pro-healing M2 phenotype, supported by morphological changes and increased TGF-β1 expression. It also established a regenerative microenvironment associated with enhanced antioxidant status, including a 2.5-fold increase in superoxide dismutase (SOD) activity, a 65% reduction in malondialdehyde (MDA), and a 2.1-fold increase in nitric oxide (NO) levels. Overall, these findings indicate that the Alg/PANI/NPs hydrogel is a promising multifunctional biomaterial that supports regenerative responses through immunomodulatory, antioxidative, and cytocompatible effects.