3D-printed magnetic scaffolds promote bone and vessel regeneration through CRYAB/PI3K-AKT and NF-κB pathways identified by proteomics

Iron oxide nanoparticles (IONPs)-based bone scaffolds have attracted increasing attention because of their potential to enhance osteogenesis and angiogenesis. However, the underlying mechanisms remain incompletely understood.We fabricated a biocompatible bone scaffold by incorporating γ-Fe2O3magnetic nanoparticles into a PLGA matrix using 3D printing technology. The biosafety and effectiveness of the scaffold was validated throughin vitrocell assays andin vivoimplantation studies. To evaluate osteogenesis and neovascularization, we employed micro-CT imaging with a vascular contrast agent. In-depth mechanistic investigations were conducted via label-free proteomic profiling and pathway enrichment analysis.The PLGA/Fe2O3scaffolds demonstrated excellent biocompatibility and promoted both bone formation and angiogenesisin vitroandin vivo. Micro-CT analysis revealed enhanced new bone and vessel formation in the presence of magnetic scaffolds. Proteomic analysis revealed that alpha-B crystallin (CRYAB) is a key regulatory protein upregulated under a static magnetic field, thereby activating the PI3K/AKT signaling cascade and promoting osteogenic differentiation. In endothelial cells, we observed the upregulation of nuclear NF-κB and HIF-1α, leading to VEGF expression and angiogenic activation.Our findings provide direct evidence that 3D-printed PLGA/Fe2O3scaffolds promote osteogenesis and angiogenesis bothin vitroandin vivo. Importantly, we report for the first time that CRYAB-mediated stabilization of β-catenin plays a central role in magnetic scaffold-induced bone regeneration, offering new insights into the design of functional bone substitutes.Image 1View The PDF