3D Printing of Bioactive Glass-Poly(ε-Caprolactone) Scaffolds for Patient-Specific Bone Implants

Craniofacial bone reconstruction presents significant clinical challenges due to the region's complex anatomy and the need to restore both structural integrity and aesthetic function. This study aimed to enhance bone regeneration at graft sites through the development of an osteoconductive bioactive glass-polymer composite for patient-specific implant (PSI) applications. Composite constructs were fabricated via extrusion-based 3D printing using varying weight ratios of bioactive glass ceramic (BGS-7) and poly(ε-caprolactone) (PCL): 2:8, 4:6, 4.5:5.5, and 5:5. Printing parameters were optimized for each formulation to ensure consistent material flow and structural fidelity. Comprehensive characterization included morphological and elemental analysis via scanning electron microscopy/energy-dispersive X-ray spectroscopy, mechanical testing (compressive, flexural, and tensile), and biological evaluation and osteogenic differentiation of human placental stem cells. Higher BGS-7 content correlated with increased incorporation of phosphate, silicon, and calcium, contributing to enhanced mechanical properties and osteogenic potential. The constructs supported high cell viability, promoted cell adhesion and spreading, and induced osteogenic differentiation, as evidenced by calcium deposition and upregulation of key markers. The high-content BGS-7/PCL (5:5) formulation demonstrated optimal printability and bioactivity and was successfully used to fabricate anatomically accurate, human-scale structure. These findings highlight the potential of BGS-7/PCL composites as scalable, biocompatible, and osteoconductive platforms for craniofacial PSI applications.