3D-Printed Polycaprolactone/Gelatin Scaffolds Reinforced with Nano-Strontium Carbonate and Bioactive Glass for Enhanced Osteogenic Performance

Abstract

Bone tissue engineering has attracted considerable interest as a strategy to address the limited regenerative capacity of large bone defects. In this study, three-dimensional (3D) scaffolds based on polycaprolactone (PCL) and gelatin (GEL), incorporating varying ratios of bioactive glass (BG) and nano-strontium carbonate (nSrCO(3)), were fabricated using extrusion-based 3D printing. The printed scaffolds exhibited well-defined, interconnected porous architectures with uniformly distributed nanoparticles. BG-containing scaffolds showed smoother fiber morphology and fewer surface particulates, with the PCL-GEL/BG formulation achieving the highest porosity (88.67 +/- 4.12). Mechanical testing revealed that scaffolds with equal proportions of BG and nSrCO(3) exhibited the highest compressive strength and Young's modulus (14.22 +/- 4.91 MPa and 21.09 +/- 5.45 MPa, respectively). Increasing nSrCO(3) content resulted in reduced wettability, swelling behavior, and degradation rate. Elemental analyses (ICP-OES and EDX) confirmed the homogeneous incorporation of bioactive elements and demonstrated the potential for controlled ionic release. In vitro studies showed cell viability exceeding 90 at days 1, 3, and 7, with the 50:50 nSrCO(3)-BG scaffold exhibiting the most favorable cellular response. DAPI staining confirmed increased and uniformly distributed cell nuclei, while ALP activity significantly increased with Sr incorporation, indicating enhanced osteogenic differentiation. Overall, these results suggest that the PCL-GEL/nSrCO(3)-BG (50/50) scaffold is a promising candidate for bone tissue regeneration.GRAPHICS.