PLA/Ti6Al4V composite scaffolds for bone tissue engineering: mechanical and thermal properties <i>via</i> FDM and bioprinting

An ideal bone substitute must exhibit high biocompatibility and mechanical reliability to facilitate integration with native bone. Polylactic acid (PLA), owing to its favorable biodegradability, thermoplastic nature, and bone-mimicking mechanical properties, has emerged as a promising scaffold material. In this study, PLA/Ti6Al4V (Ti64) composite scaffolds were fabricated using two additive manufacturing techniques: Fused Deposition Modeling (FDM) and extrusion-based 3D bioprinting. The composites were prepared in filament and bioink forms, respectively. To evaluate mineralization potential, scaffolds were immersed in simulated body fluid (SBF) for four weeks, and mass variation was recorded. Scanning electron microscopy (SEM) was used to examine surface morphology and pore architecture, while energy-dispersive X-ray spectroscopy (EDS) and elemental mapping verified the uniform dispersion of Ti64 particles within the PLA matrix. X-ray diffraction (XRD) further confirmed phase formation and the crystalline structure. Thermal analyses (TGA and DSC) indicated that increasing Ti64 content led to reduced thermal stability and crystallinity. Although the stiffness of neat PLA remained high, Ti64 reinforcement improved the compressive strength, aligning with the requirements for load-bearing applications, such as trabecular or craniofacial implants. Pore size measurements before and after SBF treatment revealed microstructural changes indicative of bioactivity. A comparison of scaffolds produced by FDM and bioprinting highlighted differences in pore geometry and biological performance. Collectively, the findings demonstrate that PLA/Ti64 composite scaffolds fabricated <i>via</i> both techniques exhibit favorable structural and mechanical characteristics, suggesting their strong potential for future use in bone tissue engineering.