The impact of brain cell metabolism and extracellular matrix on magnesium degradation

Due to its degradability, magnesium holds potential for the application as a base material for local treatment systems. Particularly for the therapy of severe brain-related diseases, local approaches are advantageous. To confirm the suitability of magnesium as a material for neural implants, information on the interaction of brain cells with magnesium is essential. Initial steps of such an evaluation need to include not only cytocompatibility tests but also the analysis of the in vitro material degradation to predict in vivo material performance. Considering the sensitivity and functional importance of neural tissue, an in-depth understanding of the processes involved is of particular relevance. Here, we investigate the influence of four different brain cell types and fibroblasts on magnesium degradation in direct material contact. Our findings indicate cell type as well as cell density-dependent degradation behavior. Metabolic activity (lactate content) appears to be crucial for degradation promotion. Extracellular matrix composition, distribution, and matrix/cell ratios are analyzed to elucidate the cell-material interactions further. Statement of Significance Thanks to their degradability, magnesium (Mg)-based materials could be promising biomaterials for local ion or even drug delivery strategies for the treatment of severe brain-related diseases. To confirm the suitability of Mg as a neural implant material, information on the interaction of brain cells with Mg is essential. Initial steps of such an evaluation need to include cytocompatibility tests and the analysis of the in vitro material degradation to predict in vivo material performance. The present study provides data on the influence of different brain cell types on Mg degradation in direct material contact. Our findings indicate cell type and cell density-dependent degradation behavior, and elucidate the role of cell metabolites and extracellular matrix molecules in the underlying degradation mechanisms. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd.