In fl uence of the extraction parameters on the cytotoxicity test results of Mg materials

Recently more and more researchers query the predictability of cytotoxicity results of biomedical Mg alloys obtained according to ISO 10993 due to signi fi cant difference between in vitro and in vivo corrosion. This study aimed to observe the infl uence of different extraction parameters (time, volume/surface ratio and medium composition) on cytotoxicity results and illustrate whether more predictable results could be obtained by adjusting the extraction parameters. The results showed that longer extraction time and smaller extraction volume/surface ratio improve the sensitivity of screening Mg materials by making inferior Mg materials release relatively more ions to the extract; and more predictable results could not be obtained by the way of simply adding bovine serum albumin (BSA) into the extraction medium to the same level in vivo or simply using fetal bovine serum (FBS) directly as extraction medium, since BSA and FBS accelerated the corrosion of Mg materials during extraction and they affected the cells' health states during the test. In order to get more predictable results, in our opinions, it is necessary to establish a database of primary cells' hazards (metal ions, pH and H2 gas) tolerance and a set of in vitro corrosion test with high similarity in vivo , which is very difficult to realize now however.