The effect of zinc oxide doping on mechanical and biological properties of 3D printed calcium sulfate based scaffolds

Fabrication of defect-matching scaffolds is the most critical step in bone tissue engineering. Three-dimensional (3D) printing is a promising technique for custom design scaffold fabrication due to the high controllability and design independency. The objective of this study is to investigate the effect of zinc oxide (ZnO) doping on mechanical and biological characteristics of 3D printed (3DP) calcium sulfate hemihydrate (CSHH) scaffolds. Crystalline phases, wettability, compressive strength and Young's modulus, human bone marrow derived mesenchymal stem cells (hMSCs) attachment, proliferation and morphology were investigated. XRD results showed that CSHH powder transformed into gypsum after the printing process due to the water content of binder. Contact angle measurements indicated that ZnO doped CSHH scaffolds have hydrophilic character, which stimulates cell attachment. The mechanical and cell culture studies demonstrated that increasing the ZnO doping concentration both mechanical strength and cell proliferation on CSHH scaffolds were enhanced.