In vitro responses of bone-forming MC3T3-E1 pre-osteoblasts to biodegradable Mg-based bulk metallic glasses

In light of the superior property profile of favorable biocompatibility, proper corrosion/degradation behavior and good mechanical properties, Mg-based bulk metallic glasses (BMGs) are considered as potential biodegradable biomaterials. In the present study, in vitro responses of bone-forming MC3T3-E1 pre-osteoblasts to Mg-Zn-Ca-Sr BMGs were studied in order to assess their feasibility to serve as orthopedic implants. The Mg-Zn-Ca-Sr BMGs were much more capable of supporting cell adhesion and spreading in comparison with crystalline AZ31B Mg alloy. The Mg-Zn-Ca-Sr BMG extracts showed no cytotoxicity to and slightly stimulated the proliferation of pre-osteoblasts. The cells cultured in 100% BMG extracts exhibited lower alkaline phosphatase activity as compared with that in negative control, which could be mainly ascribed to the inhibition of high concentrations of Zn ions on cell differentiation. With decreasing the extract concentration, the inhibitory effect was diminished and the 5% BMG extract exhibited slight stimulation in cell differentiation and mineralization. The high corrosion resistance of BMGs contributed to smaller environmental variations, compared with AZ31B alloy, thus lowering the unfavorable influences on cellular responses. A comparison among the biodegradable Mg-, Ca- and Sr-based BMGs for their biomedical applications is presented.