3D-Printed Poly(ε-Caprolactone)/CaCO3 Biocomposite Meshes for Bone Tissue Engineering: EnhancedMechanicalStrength and Cytocompatibility

Poly(ε-caprolactone) (PCL) is a biodegradable and biocompatible polyester widely used in biomedical scaffolds. However, its relatively low mechanical strength and limited cell adhesion properties remain major challenges for bone tissue engineering applications. This study developed a 3D-printed PCL mesh enhanced with calcium carbonate (CaCO3) to improve mechanical strength and cytocompatibility. PCL was synthesized via ring-opening polymerization at 120 °C for 72 h using 0.015 mol % of Sn(OnBu)2 as the initiator, resulting in a high molecular weight polymer of 189 kg/mol. The addition of 5 wt % CaCO3 into the PCL matrix enhanced the flexural performance of the biocomposite mesh compared to pure PCL, with flexural strength increasing from 2.11 ± 0.46 to 4.17 ± 1.15 MPa and Young’s modulus increasing from 81 ± 14 to 130 ± 33 MPa, a value within the range reported for native trabecular bone. Cytocompatibility was evaluated using L929 fibroblasts and the MTT assay, following ISO 10993-5 guidelines, and demonstrated noncytotoxic behavior, with cell viability ranging from 80% to 110% over 28 days. Additionally, MG-63 osteoblast-like cells showed increased proliferation on the PCL-CaCO3 mesh. These results demonstrate the feasibility of the 3D-printed PCL-CaCO3 mesh as a mechanically reinforced, cytocompatible scaffold candidate for bone tissue engineering applications, warranting further evaluation of osteogenic potential and in vivo performance.