Fabrication, in vitro and in vivo properties of β-TCP/Zn composites

Abstract

In recent years, biodegradable Zn-based materials became a hopeful approach for new generation biomedical implants due to their acceptable mechanical performance, moderate biodegradation rate, and good biocompatibility. In this study, the combination of high-energy planetary milling and spark plasma sintering process were employed to fabricate n vol% β-TCP (n = 0, 0.5, 1, 3, 5, 10)/Zn composites with uniform microstructure and high relative density. The microstructure investigation, mechanical performance, degradation behavior, in vitro and in vivo properties of the composites were systematically investigated. As a result, β-TCP nanoparticles were homogeneously dispersed in the whole composites and possessed a good bonding interface with the Zn matrix. The degradation of pure Zn and β-TCP/Zn composites in vitro and vivo is a uniform corrosion process. Enhanced corrosion resistance attributed to the addition of β-TCP with a optimized content. The evaluation of osteogenic differentiation process showed that the addition of β-TCP induced the up-regulated expression of osteogesis-related genes (ALP) in mouse preosteoblasts, thus improving the osteogenic ability. As revealed by animal experiments, six months after implantation of pure Zn and 3TCP/Zn components, the blood biochemical parameters of rats showed no obvious tissue inflammation, indicating excellent in vivo biocompatibility of experimental materials. Histological investigation showed that with prolonged implantation time, the 3TCP/Zn components were more effective than pure Zn in promoting new bone formation. In summary, 3TCP/Zn matrix components developed in the present study should be useful for orthopedic implants.