BACKGROUND: Poly (lactic acid) (PLA) is a biodegradable polyester that has been exploited for a variety of biomedical applications, including tissue engineering. The incorporation of b-tricalcium phosphate (TCP) into PLA has imparted bioactivity to the polymeric matrix. METHODS: We have modified a 90%PLA-10%TCP composite with SiO2 and MgO (1, 5 and 10 wt%), separately, to further enhance the material bioactivity. Filaments were prepared by extrusion, and scaffolds were fabricated using 3D printing technology associated with fused filament fabrication. RESULTS: The PLA-TCP-SiO2 composites presented similar structural, thermal, and rheological properties to control PLA and PLA-TCP. In contrast, the PLA-TCP-MgO composites displayed absence of crystallinity, lower polymericmolecular weight, accelerated degradation ratio, and decreased viscosity within the 3D printing shear rate range. SiO2 andMgO particles were homogeneously dispersed within the PLA and their incorporation increased the roughness and protein adsorption of the scaffold, compared to a PLA-TCP scaffold. This favorable surface modification promoted cell prolif-eration, suggesting that SiO2 and MgO may have potential for enhancing the bio-integration of scaffolds in tissueengineering applications. However, high loads of MgO accelerated the polymeric degradation, leading to an acid environment that imparted the composite biocompatibility. The presence of SiO2 stimulated mesenchymal stem cells differentiation towards osteoblast; enhancing extracellular matrix mineralization, alkaline phosphatase (ALP) activity, and bonerelated genes expression. CONCLUSION The PLA-10%TCP-10%SiO2 composite presented the most promising results, especially for bone tissue regeneration, due to its intense osteogenic behavior. PLA-10%TCP-10%SiO2 could be used as an alternative implant forbone tissue engineering application.