Fig. 3. Live/dead assay and immunocytochemical analysis to observe cell viability and cellular morphology of MC3T3-E1 preosteoblasts cultured on 3D printed PLA and GO-PLA films. (a) Fluorescence micrographs and their quantification at (b) 24 h and (c) 48 h. (d) Immunofluorescence staining of cells at 5 DIV. TRITC (red) and DAPI (blue) denote F-actin and nucleus, respectively. Ph indicates phase contrast. (e) F-actin spreading area and (f) the number of the nucleus quantified based on images of (d). Scale bars of (a) and (d) represent 100 μm. The asterisk represents statistical difference (*p < 0.05).