Biodegradable porous Zn-1Mg-3βTCP scaffold for bone defect repair: In vitro and in vivo evaluation

Zn-based materials are promising as bone repair materials, but their poor mechanical property and bioactivity as well as low degradation rate render the potential application. Rational structural and material design can address the concerns. In this study, porous Zn-1 wt.%Mg-3 vol.%β-TCP scaffolds with 40% and 60% preset porosities were fabricated via heating-press sintering using NaCl particles as space holders, and their mechanical properties, in vitro degradation behavior, cytotoxicity and in vivo osteogenic activities were evaluated. The results showed that the actual porosities of the scaffolds were 22% and 50%. Mg exists in the form of Zn2Mg and Zn11Mg2, while β-TCP evenly distributed in the matrix. The compressive yield strength of scaffolds ranges from approximately 58.46 to 71.04 MPa, which is close to that of cancellous bone. The in vitro degradation tests showed that the corrosion rate of the scaffolds was in the range of about 2.73–4.28 mm y–1. Moreover, the scaffolds not only provided great space for osteoblasts adhesion and proliferation in vitro but also possessed favorable degradability and osteogenic activity in vivo. The porous Zn-1 wt.%Mg-3 vol.%β-TCP scaffolds manifest reliable mechanical properties, desirable degradability, and osteogenic activity, which are promising as next-generation bone repair materials.