Cell proliferation and growth on the 3D-printed scaffolds. (A) SEM micrographs of MC3T3-E1 cells grown for 14 days of culture period on the GEL, GEL/1%dbPTs, and GEL/3%dbPTs composite scaffolds (from top to bottom). Cell spreading and coverage are visible for all scaffolds. Scale bars: 20 μm (left), 5 μm (right), 2 μm (insets). (B) Magnified SEM images of the cells which covered the pore structure of the scaffold in circular patterns. Scale bar: 100 μm (left), 10 μm (right). (C) SEM images of cells covering the surface of the scaffolds with a multilayered structure after 14 days of culture period. Scale bar: 1 μm. (D) Proliferation assay result of cells on the GEL/dbPTs scaffolds (n = 6) quantified by PicoGreen assay normalized to TCP control on day 1. Data are shown as mean ± SD and ∗, ∗∗, ∗∗∗, and ∗∗∗∗ indicate p < 0.05, p < 0.01, p < 0.001, and p < 0.0001 statistically significant data are analyzed by one-way ANOVA.