Study of Thermal-Responsive Poly-L-lactic acid/Nanohydroxyapatite Composite Filament and its 3D Printing

There have been critical needs for the development of biomedical and cost-effective filaments for fused deposition modeling 3D printer. In the present work, we prepared poly-L-lactic acid (PLLA)/10 wt % nanohydroxyapatite (nHA) composite filaments suitable for 3D printing by melt extrusion. Scanning electron microscopy and tensile tests were carried out to examine surface morphology and tensile properties of the materials. Differential scanning calorimetry and thermal gravimetric analysis had been performed in order to assess filaments’ suitability for the 3D printing process, in terms of melting point, degradation temperature and so on. Thermally-activated shape memory response of the composites had also been studied. The printing effects of filaments were tested using a desktop 3D printer. The samples printed in different directions were used to perform compression and bending experiments. PLLA/nHA macroporous bone scaffold fabricated by 3D printing showed shape memory effect retained from PLLA/nHA composite. Even though the bone scaffold we obtained was far from the ultimate application in minimally invasive surgery, possible solutions to print more satisfying scaffold are discussed in the conclusion of this article.