3D printing biocompatible L-Arg/GNPs/PLA nanocomposites with enhanced mechanical property and thermal stability

Blending graphite nanoplatelets (GNPs) with polylactic acid (PLA) is a conventional approach endowing the GNPs/PLA nanocomposites with enhanced mechanical and thermal properties. Meanwhile, L-Arginine (L-Arg) has been proved to be effective GNPs modifiers, which can be used to improve the solubility and compatibility of GNPs in PLA. On the other hand, additive manufacturing offers a novel and unique way to fabricate components with complex structure and special functions, which can significantly expand the application of material in many fields. This study demonstrated the fused deposition modeling (FDM) 3D printing L-Arg/GNPs/PLA nanocomposites with enhanced mechanical property and thermal stability in conjunction with its potential application as biomaterials. Nanocompsites were prepared by solvent-based mixing method and extruded into filaments for FDM printing. The addition of L-Arg/GNPs significantly improved the tensile and flexural strength of PLA matrix, 43.6% in tensile strength and 28.5% in flexural strength with optimal loading of 2 wt% L-Arg/GNPs. The thermal stability of L-Arg/GNPs/PLA nanocomposites gradually improved, with 60 °C increase in degradation temperature and 7% increase in remaining residual weight. Furthermore, MTT cytotoxicity assay of the 3D printed nanocomposites showed the good biocompatibility of the L-Arg/GNPs/PLA nanocomposites, which indicates the promising prospect of being applied as biomaterial in bone tissue engineering.