Abstract
This study addresses the clinical challenge of nonunion in spinal interbody fusion by developing a novel composite implant: a porous tantalum (PTa) cage loaded with concentrated growth factors (CGF). The CGF-PTa cage synergistically combines the mechanical strength and osteoconductivity of chemically vapor-deposited PTa with the sustained release of angiogenic (VEGF) and osteogenic (TGF-β and IGF-1) factors from CGF. Using a rat extreme lateral interbody fusion (XLIF) model, the research systematically evaluates the efficacy of this composite in promoting bone regeneration and spinal fusion. Results from radiography, micro-CT, biomechanical testing, histological staining, and immunohistochemistry consistently show that CGF-PTa significantly enhances bone ingrowth, fusion rate, and mechanical stability compared to PTa alone. The findings also reveal that CGF facilitates angiogenesis and osteogenesis by modulating the local healing microenvironment and promoting vascular-osteogenic coupling. Importantly, the CGF-PTa system demonstrated excellent biocompatibility and biodegradability in vivo, with no observed systemic toxicity. This work highlights the potential of combining bioactive factors with porous metallic scaffolds to overcome the limitations of inert implants in avascular environments, offering a promising strategy for functional optimization of interbody fusion devices and their future clinical application.