A Magnetic Iron Oxide/Polydopamine Coating Can Improve Osteogenesis of 3D-Printed Porous Titanium Scaffolds with a Static Magnetic Field by Upregulating the TGFβ-Smads Pathway

3D-printed porous titanium–aluminum–vanadium (Ti6Al4V, pTi) scaffolds offer surgeons a good option for the reconstruction of large bone defects, especially at the load-bearing sites. However, poor osteogenesis limits its application in clinic. In this study, a new magnetic coating is successfully fabricated by codepositing of Fe 3 O 4 nanoparticles and polydopamine (PDA) on the surface of 3D-printed pTi scaffolds, which enhances cell attachment, proliferation, and osteogenic differentiation of hBMSCs in vitro and new bone formation of rabbit femoral bone defects in vivo with/without a static magnetic field (SMF). Furthermore, through proteomic analysis, the enhanced osteogenic effect of the magnetic Fe 3 O 4 /PDA coating with the SMF is found to be related to upregulate the TGF β -Smads signaling pathway. Therefore, this work provides a simple protocol to improve the osteogenesis of 3D-printed porous pTi scaffolds, which will help their application in clinic.