Fabrication of Polycaprolactone-Hydroxyapatite Composites Filaments for FDM 3D Printing of Bone Imitation Application

Three-dimensional printing (3DP) has been widely adopted in various field thanks to its ability to easily and quickly produce complex 3D structures. In recent years, it has been widely used in the fabrication of bone scaffolds, especially in the biomedical field. The scaffold is inserted into the fractured or injured regions to promote bone cell migration and in-growth. Therefore, 3DP is useful for personalized bone scaffolds fabrication. Until now, various 3DP techniques such as hot melt, pneumatic, and piston extrusion have been used in scaffold fabrication in literature. However, the fused deposition modeling (FDM) method using feed filaments has hardly been reported, even though it provides several advantages such as low cost, versatility, and convenience.<br/>In this work, we fabricated polycaprolactone (PCL)/hydroxyapatite (HA) composites filaments, a raw material mainly used for bone scaffold. Using the fabricated filaments with the wt.% of HA from 5 to 25, specimens were printed by commercial 3D printer for evaluating mechanical and electrical properties. Specially, mechanical tensile test of the filaments and specimens were carried out. In addition, electrical dielectric properties of PCL/HA composites, which was not reported in other studies, was also explored for the potential application as a bone mimetic testbed for implantable wireless devices. These results indicate that mechanical and dielectric properties can be tuned through the adjustment of HA content. Therefore, PCL/HA composites filaments can be usefully used in various fields by providing a facile fabrication of a biocompatible structure.