Magnetically Guided Mechanoactive Mineralization Scaffolds for Enhanced Bone Regeneration

Abstract

A multifunctional bone tissue engineering scaffold combining spontaneous biomineralization with magnetically induced dynamic mechanical stimulation is developed to promote stem cell osteogenic differentiation and accelerate matrix formation. Inspired by the “rebar-concrete” structure, a composite scaffold (PGS-P@MGel) combines 3D-printed phosphate-modified poly(glycerol sebacate) (PGS-P) with a hydrogel containing PDA@Fe3O4 magnetic nanoparticles (MGel). The 3D-printed framework provides spontaneous mineralization and structural integrity, accelerating calcium deposition and providing stable support. The magnetic hydrogel injected into the scaffold enables controllable dynamic mechanical signals under external magnetic fields, directing stem cell fate. Mechanotransduction activates the Piezo1 pathway, inducing β-catenin and YAP overexpression to enhance osteogenesis. In vitro/vivo studies demonstrate this functionalized composite scaffold exhibits excellent biocompatibility, promotes angiogenesis, enhances osteogenic differentiation efficiency, and demonstrates superior osteogenic capacity under the influence of an external magnetic field. This multifunctional scaffold, with its spontaneous mineralization and mechanoactive, effectively regulates stem cell osteogenic differentiation and promotes bone defect repair, opening new dimensions for the development of bone tissue engineering scaffolds and providing valuable insights for large-scale bone defect repair.