Tunable Polycaprolactone‐Gelatin Methacryloyl Composites for Fused Deposition Modeling Musculoskeletal Scaffold Fabrication

The global musculoskeletal burden continues to outpace standard of care transplantation efforts and existing tissue engineering solutions, necessitating further development of scalable biomaterials. In this study, we introduce a novel synthesis of polycaprolactone-gelatin methacryloyl (PCL-GelMA) composite filament, compatible with standard fused deposition modeling (FDM) 3D printers, for scalable and customizable scaffold fabrication. By incorporating 15% and 30% (w/w) GelMA into a PCL matrix, we achieved tunable modulation of surface roughness, hydrophilicity, and degradation kinetics. Mechanical testing revealed nonlinear dependencies between GelMA content and tensile properties, suggesting that variation in GelMA particle size and distribution leads to a concentration-dependent trade-off between stiffness and structural integrity. Human mesenchymal stem cells (hMSCs) cultured on printed scaffolds maintained viability and proliferative capacity. By mitigating solvent toxicity through upstream processing, physically integrating constituents into a unified bulk matrix, and leveraging the accessibility of FDM printing, this material platform enables scalable translation and further biomaterial exploration.