Fig. 3

A Shape of graphene, B shape of graphene oxide. C Cells grown in the absence of BMP-2. Control with coverslips is shown as a reference. D Cells grown in the presence of BMP-2. Conventional plain coverslips were used as a positive control. E Osteogenic differentiation visualized by Alizarin Red staining after 12 days of incubation, on PDMS (i) with induction and (ii) without induction, on G (iii) with induction and (iv) without induction, and on GO (v) with induction (vi) and without induction. Scale bars are 200 μm. F The quantification demonstrated a significantly higher amount of Alizarin Red staining in the MSCs differentiated on G (*p < 0.05; n = 4 for each group) (A, B) The reprint of this figure from [22] is permitted by the Hindawi Publishing Corporation (C, D) The reprint of this figure from [42] is permitted by the American Chemical Society. (E, F) The reprint of this figure from [13] is permitted by the American Chemical Society