J Mater Sci: Mater Med 24:989-15. 3 W. Zhou, et al (2010) Corros Sci 12:1035-7. 4 P. Marie, et al. (2001) Calcif Tissue Int 69:121-9. ACKNOWLEDGEMENTS: ...
European Cells and Materials Vol. 26. Suppl. 5, 2013 (page 36)
ISSN 1473-2262
Influence of strontium concentration on in vitro corrosion property and cytocompatiblity of ternary Mg-Zn-Sr alloys D Tie1, 2, RG Guan1, T Cui1, LL Wu2, LL Song1, HM Qin3 1 Northeastern University, Shenyang, China. 2 HZG Research Center, Geesthacht, Germany. 3 Northern Hospital, Shenyang, China. INTRODUCTION: Magnesium’s functions in metabolic processes and its electrochemical reactivity make it ideal as degradable implants [1]. Mg-Zn-Sr alloys were proven suitable as potential biomaterials in our previous work [2]. In the present study, four Mg-Zn-Sr alloys designed by our own were compared to reveal Sr’s influence on bio-corrosion process and cytocompatibility. METHODS: ZJ41B (4.0wt% Zn, 0.5wt% Sr), ZJ41C (1.0wt% Sr), ZJ41D (1.5wt% Sr), ZJ42A (2.0wt% Sr) alloys and pure Mg were cast and rolled. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) were employed for surface analysis. Immersion test in simulated body fluid (SBF) was carried out for 72h. The cytocompatibility of the alloys towards L929 cell line was characterized using polarizing microscope with fluorescent staining. RESULTS: The size and amount of second phases increased with higher concentration of Sr (Fig. 1a).
corrosion rate than pure Mg (2.49±0.27mm/y, Fig. 1c). After 72h cell culture, the survival rates of L929 cells on test alloys all exceeded 90% (Fig. 2). Higher concentration of Sr content did not induce additional cytotoxicity. Cell adhesion density and degree of cell extension was not significantly different from the control group (Fig. 2a).
Fig. 2: Polarizing microscope images of L929 cells on ZJ alloys after fluorescent staining (a); cell viability after 72h culture (b). DISCUSSION & CONCLUSIONS: Presence of second phases improves the alloys’ corrosion resistance by increasing general corrosion potential [3], which assures better cytocompatibility, while high concentration (>1.5wt%) of Sr accelerates the corrosion process by inducing localized corrosion. As an essential element for human body, Sr improves Mg alloys’ corrosion and mechanical properties and also benefits bone generation [2, 4]. The alloys with 0.5-1.0wt% Sr content show the biggest potentials as biodegradable implant materials due to their balanced property profile.
Fig. 1: Microstructures of the four alloys (a); the SEM image and composition of corrosion layer by EDS area scanning of ZJ41B (b); corrosion rate calculated by mass loss and magnesium ion release (c). (Mean value ± SD, n=3, *p
