Cellular reactions to biodegradable magnesium alloys of human growth plate chondrocytes and osteoblasts.

Purpose: In the last decades operative fracture treatment using elastic stable intramedullar nails (ESINs) mainly took over conservative alternatives in children. The development of biodegradable materials that could be used for ESINs would be a further step towards treatment improvement. Due to its mechanic and elastic properties, magnesium seems to be an ideal material for biodegradable implant application. The aim of this study was therefore to investigate the cellular reaction to biodegradable magnesium implants in vitro. Methods: Primary human growth plate chondrocytes and MG63 osteoblasts were used for this study. Viability and metabolic activity in response to the eluate of a fast and a slower degrading magnesium alloy were investigated. Furthermore, changes in gene expression were assessed and live cell imaging was performed. Results: A superior performance of the slower degrading WZ21 alloy’s eluate was detected regarding cell viability and metabolic activity, cell proliferation, and morphology. However, the ZX50 alloy’s eluate induced a favourable up-regulation of osteogenic markers in MG63 osteoblasts. Conclusion: This study showed that magnesium alloys for use in biodegradable implant application are well tolerated in both, osteoblasts and growth plate chondrocytes respectively.