Fig. 3

Morphology of HRD at 21 days: a control group, the well is densely covered with cells; b pure Mg, almost no cells compared with control; c Mg2Ag, the well is densely covered with cells; d Mg10Gd, many fewer cells compared with control but more than at day 7; e WE43, similar appearance to Mg10Gd with somewhat more cells than at day 7; f crystal formation was observed for all materials (the image shows the pure Mg well). Asterisk magnesium disc. Scale bar 100 µm