Mechanical and Biological Properties of Additive Manufactured Polyester-Based Scaffolds Treated by Surface Etching

Currently, material extrusion-based additive manufacturing (MEAM) technique, also known as fused filament fabrication (FFF) technique has been widely used to prepare customized porous scaffolds for bone tissue engineering. However, porous scaffolds often lack desirable osteogenic properties due to the poor hydrophilicity of polymer materials used for FFF technique. In this work, biocompatible materials suitable for FFF technique are prepared by blending polycaprolactone (PCL), polylactic acid (PLA), and tricalcium phosphate (TCP) at various compositions. These composite materials are subsequently printed into cylindrical scaffolds with controllable pore sizes ranging from 200–800 µm, by regulating the infill density during the FFF process. The FFF-printed scaffolds have the highest modulus at a PLA/PCL ratio of 0.7 and a pore size of ≈ 200 µm. Furthermore, surface treatment is applied to these FFF-printed scaffolds in sodium hydroxide solution. As a result, the surface roughness, hydrophilicity and serum adsorption of the scaffolds are significantly enhanced. More importantly, these surface-treated scaffolds can promote the osteogenic differentiation of MC3T3-E1 cells, comparable to commercial Bio-Oss substitutes. Thus, this study offers a cost-effective technique for the development of bioactive scaffolds for potential bone tissue engineering applications.