Bioactivity, mineralization, and mechanical properties of 3D-printed nano TiO2-reinforced polymer composite immersed in SBF

Abstract

In this work, 3D-printed polylactic acid (PLA) composites reinforced with 2 wt% nanosized titanium dioxide (TiO₂) were fabricated via fused filament fabrication (FFF) to enhance surface bioactivity and overall material performance. The incorporation of TiO₂ markedly improved the apatite-forming ability of the composite surfaces, as evidenced by increased calcium and phosphorus deposition up to 0.032 and 0.046 %, respectively. Surface roughness measurements revealed that TiO₂ addition led to smoother and more uniform 3D-printed surfaces. Mechanical testing showed ∼24 % reduction in tensile strength and ∼17 % reduction in bending force compared to unreinforced PLA-polymer, predominantly attributed to nanoparticle-induced microvoid formation; despite that, the mechanical properties remained within acceptable ranges for biomedical applications. These findings suggest that the enhanced mineralization behavior, improved surface characteristics, and satisfactory mechanical integrity of TiO₂–PLA composites render them promising candidates for load-bearing biomedical applications, such as bone fixation devices and regenerative bone scaffolds.