Sustainably releasing osteogenic trace elements from montmorillonite intercalated hybrid nanocomposites accelerates bone regeneration

Optimizing scaffold components and architectures to achieve endogenous osteogenesis is a prospective advancement for bone tissue engineering. Here, montmorillonite was introduced as a reinforcing phase into a dopamine-mediated biomimetic organic-inorganic hybrid hydrogel via an intercalation structure, improving the bone regenerative scaffold (HDC-HAp-MMT) architectures through montmorillonite-polymer interactions and polyphenol-mediated multiple reactions, manifested as enhanced mechanics and delayed degradation. Specifically, sustainably releasing beneficial trace elements into the regenerative microenvironment provides crucial osteogenic biochemical signals. Montmorillonite-reinforced hydrogels promoted bone marrow mesenchymal stem cell proliferation and osteogenic differentiation in vitro. The HDC-HAp-MMT scaffolds significantly enhanced mineral deposition (6.91-fold mechanical augmentation after 30 days) in an ectopic osteogenesis model while achieving 80.94% bone volume fractions and 85.89% bone mineral density comparable to natural bone in an orthotopic rabbit cranium repair experiment. This strategy may represent a novel approach for bioactive bone regenerative scaffolds.