Design of experiment optimization of artificial bone construct fabrication via direct ink writing of hydroxyapatite

For bone tissue engineering, a delicate balance between bioactive material selection and scaffold porosity must be reached to permit sufficient implant mechanical properties and natural bone ingrowth. To accomplish this combination, a resolution test was developed to optimize spatial and shape accuracy for a 3D printing paste extrusion system used to create the intricate features associated with natural bone morphology. The results of this study outline various printing parameters including rheological requirements, print speed, and nozzle head shape and scale that are necessary to maximize print quality. In addition, artificial bone constructs were fabricated using a calcium phosphosilicate nanoparticle doped hydroxyapatite paste. This printing system will continue to be the foundation for fabricating future scaffolds and experimentation with design and material optimization for osteogenesis, angiogenesis, and suitable mechanical loading.