Voronoi 3D: A Novel Approach to Design 3D PLA/HAp Printed Scaffolds for Tissue Engineering Applications

Abstract

Bone repair is one of the most studied fields within tissue engineering since it is one of the most affected structures in the human body. Biomaterials based on calcium phosphate such as hydroxyapatite (HAp) have demonstrated to be promising solutions, due to its capacity to mimic the mineral composition and/or its porous structure. Additionally, using additive manufacturing alongside Computer-Aided Design Software, has granted the opportunity to generate cellular scaffolds for replacement or bone grafts thanks to its controllable mechanical properties, porosity, pore size and structural form. For this reason, the aim of this project is to design, fabricate and characterize PLA/HAp 3D printed scaffolds for tissue engineering applications. For this, HAp was first synthesized through the Microwave-Assisted Hydrothermal Method using Ca(NO3)2, K2(HPO4) and KOH as precursor and glutamic acid as growth inhibitor, obtaining HAp nanofibers with a hexagonal structure enhancing its mechanical properties. Furthermore, these HAp nanofibers were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to find out the dimension, morphology, topology, orientation, and crystalline structure of the nanofibers. In addition, a variety of 3D bone scaffolds with defined and interconnected pores mimicking the morphology and permeability of the trabecular bone, were designed using 3D Voronoi tessellation method through Rhinoceros 7 with Grasshopper. These scaffolds were fabricated using the extrusion method, where PLA was melted and extruded as a filament. Layer by layer the filament was deposited to create scaffolds with a controlled arrangement of struts and pore dimensions without the need for a binder.