Fabrication and Characterization of 3D-Printed Polylactide Composite Scaffolds with Modified Graphene

Abstract

In this study, we introduce novel multifunctional biomaterial inks for extrusion-based 3D bioprinting to create scaffolds for potential tissue engineering. This study focuses on developing composite materials by incorporating alkyl ketene dimer (AKD)-modified graphene nanoplatelets (GP) into polylactide (PLA) using a solvent casting technique. GP was synthesized via electrolytic exfoliation in an aqueous poly(sodium 4-styrenesulfonate) solution and subsequently modified with AKD by ball milling to enhance dispersion and PLA compatibility. Physical and chemical characterization confirmed the successful synthesis and structural properties of the AKD-modified GP. PLA-GPD20 films containing 20 wt % AKD-modified GP exhibited significantly improved elongation at break and maintained tensile strength comparable to neat PLA. All biomaterial composite films exhibited high stiffness, as evidenced by glass transition temperatures above room temperature, and electrical conductivity in the semiconductor range. The results highlight the significant positive impact of AKD on the physical and electrical properties, as well as the printability, of the composites. The printability performance potential was evaluated using 10 wt % PLA-GPD20 biomaterial inks to generate scaffolds with different patterns. The mechanical testing of the printed scaffolds revealed that the tensile strength and modulus increased with the incorporation of GPD20. The printing orientation is an effective parameter for tuning the balance between stiffness and ductility; scaffolds printed at 90° exhibited higher Young’s modulus but lower elongation at yield and tensile strength than those printed at 45°. Furthermore, incorporating AKD into GP/PLA composites improved hydrophobicity. The results suggest that AKD-modified graphene composites hold substantial promise for the development of advanced multifunctional materials for tissue engineering applications.