Effects of silica and zinc oxide doping on mechanical and biological properties of 3D printed tricalcium phosphate tissue engineering scaffolds

Abstract

Objectives: To evaluate the effects of silica (SiO 2) (0.5 wt%) and zinc oxide (ZnO) (0.25 wt%) dopants on the mechanical and biological properties of tricalcium phosphate (TCP) scaffolds with three dimensionally (3D) interconnected pores. Methods: Scaffolds were created with a commercial 3D printer. Post sintering phase analysis was determined by X-ray diffraction. Surface morphology of the scaffolds was examined by field emission scanning electron microscopy (FESEM). Mechanical strength was evaluated with a screw driven universal testing machine. MTT assay was used for cellular proliferation characteristics and cellular morphology was examined by FESEM. Results: Addition of dopants into TCP increased the average density of pure TCP from 90.8 ± 0.8% to 94.1 ± 1.6% and retarded the β to α phase transformation at high sintering temperatures, which resulted in up to 2.5 fold increase in compressive strength. In vitro cell-materials interaction studies, carried out using hFOB cells, confirmed that the addition of SiO 2 and ZnO to the scaffolds facilitated faster cell proliferation when compared to pure TCP scaffolds. Significance: Addition of SiO 2 and ZnO dopants to the TCP scaffolds showed increased mechanical strength as well as increased cellular proliferation. © 2011 Academy of Dental Materials. All rights reserved.