In vitro analysis of Mg scaffolds coated with polymer/hydrogel/ceramic composite layers

Magnesium (Mg), as a biodegradable metal, has recently been considered to be used in hard tissue engineering scaffold design. However, the fast release of hydrogen gas during exposure of Mg to corroding biofluids significantly limits the cytocompatibility of the scaffolds. To overcome this key drawback, in this study, the surfaces of Mg scaffolds are modified by polymer/hydrogel/ceramic layers consisting of polycaprolactone (PCL), gelatin (Gel) and bioactive glass (BaG). A detailed study has been performed on the in vitro mechanical properties of the Mg scaffold coated by PCL–BaG/Gel–BaG compared with the uncoated one. Our results show that the coated scaffold can keep its mechanical integrity three times longer than the uncoated one. To assess cytocompatibility, human osteoblast Saos-2 cells were cultured on the surface of the scaffolds. Cell attachment and growth were evaluated by scanning electron microscopy and cell viability assays, respectively. While no cell could attach on the uncoated scaffold, cell viability and growth are acceptable on the Mg scaffold/PCL–BaG/Gel–BaG.