In vitro degradation behavior and cytocompatibility of ZK30/bioactive glass composites fabricated by selective laser melting for biomedical applications

Abstract

In practice, the poor formability and high degradation rate of Mg-based alloys are perceived as two major limitations for their more extensive applications in the biomedical field. Selective laser melting (SLM), as one of the advanced additive manufacturing techniques, is potential for the manufacturing of customized Mg-based implants with improved formability and corrosion resistance. Moreover, the integration of bioactive glass (BG) into Mg-based alloys could endow the materials with further enhanced corrosion resistance and favorable biological performance. In the current work, biomedical Mg-based biodegradable composites (ZK30/xBG, x = 0, 5, 10, 15 wt%) with ZK30 alloy as the matrix and BG (45S5) as the reinforcement were fabricated by SLM. The results showed that the BG particles homogeneously distributed in the matrices of SLM-fabricated ZK30/xBG composites. Meanwhile, the introduction of the BG particles led to improved microhardness of the composites. When immersed in simulated body fluid (SBF), more precipitations (primary Ca–P compounds and partial Mg(OH)2) formed on ZK30/10BG and ZK30/15BG surfaces compared to ZK30 and ZK30/5BG group. The hydrogen evolution and electrochemical polarization tests showed that corrosion resistance of various specimens was in the following order: ZK30/10BG > ZK30/5BG > ZK30/15BG > ZK30. In addition, the in vitro cell viability results showed that ZK30/10BG and ZK30/15BG were more cytocompatible than ZK30 and ZK30/5BG. Overall, these results indicate that the combination of SLM technique and BG integration could be used to manufacture ZK30/xBG composites with enhanced corrosion resistance and favorable formability. Moreover, the ZK30/10BG composite is promising for orthopedic applications considering its combination of favorable bioactivity, corrosion resistance and cytocompatibility.