Biomedical Engineering Reference
In-Depth Information
Fig. 11. The typical surface morphology of Mg-4.0 Zn-0.2 Ca alloy after electrochemical
measurements: (a) macrostructure (b) microstructure
Fig. 12. XRD patterns of the corrosion products of Mg-4.0 Zn-0.2 Ca alloy immersed in
Hank's solution.
3.4 Cytotoxicity assessments
The pH values of the extraction medium were measured, and only the values of Mg-1.0 Zn,
Mg-2.0 Zn, Mg-3.0 Zn, Mg-4.0 Zn, Mg-4.0 Zn-0.2 Ca and Mg-4.0 Zn-0.5 Ca alloys were below
than 8.0. That's mean all of these alloys have a potential probability used as the biomaterials.
As the economic reason, only Mg-4.0 Zn-0.2 Ca was selected to evaluate the cytotoxicity
through examining both the viability and morphology of L-929 cells in this study.
The morphologies of L-929 cells cultured in different extracts after 7 day incubation were
shown in Fig.13. It could be seen that the cell morphologies in different extracts were normal
and healthy, which was similar to that of the negative control. Fig.14 shows the RGR of L-
929 cells after 2, 4 and 7 days of incubation. There was no significant difference between the
RGR of cells in the extracts and those in the negative control. According to standard ISO
10993-5: 1999 [32], the cytotoxicity of these extracts was Grade 0-1. In other words, the Mg-
4.0Zn-0.2Ca alloy has a level of biosafety suitable for in cellular applications.
