Vitamin D3 Release from Traditionally and Additively Manufactured Tricalcium Phosphate Bone Tissue Engineering Scaffolds

Bone is a randomized, complex porous network which researchers have tried to mimic within bone tissue engineering scaffolds. The objective of this study was to understand the effects of random and controlled scaffold porosity on the release kinetics of vitamin D-3 to determine if a designed porous structure was comparable in effectiveness on osteoblast proliferation to the randomized essence of natural bone. In this study, porous tricalcium phosphate (TCP) scaffolds were prepared by fugitive material removal method using naphthalene and 3D printing to model random and controlled porosity, respectively. Scaffold comparison was made based on open pore volume percentage of which naphthalene scaffolds had 45.8 +/- 1.5% and 3D printed scaffolds had 48.9 +/- 2.5%, Comparative analysis of traditional bioceramic processing to additive manufacturing is limited especially regarding drug release kinetics. Results showed the naphthalene scaffold surface area was only 0.3% that of 3D printed scaffolds due to the lower open pore interconnectivity. This increase in surface area produced higher release of drug and osteoblast proliferation in 3D printed scaffolds comparatively. By 11 days, osteoblast proliferation was enhanced by 64% from scaffolds manufactured using 3D printing compared to traditional processing. Understanding the effects of processing methods of TCP scaffolds on the release kinetics of vitamin D-3 and the system effects on cells can aid in low load bearing applications for bone tissue engineering.