No tissue formation was observed in the acellular GelMA constructs, H&E (A) and Pol (B) images. H&E stained embedded paraffin and sectioned constructs exhibited high cellularity (C, D), extensive extracellular matrix and dentin/bone-like tissue formation at the DM GelMA layer. The dashed line separates the biomimetic pulp organ (DM in the bottom layer) from the biomimetic enamel organ (DE in the top layer). Pol images (E, F) revealed organized collagen formation within the CSG constructs. IF images (G, H) show the expression of VM (green) by DM cells in the biomimetic pulp organ layer, and ECAD (red) by the DE cells in the biomimetic enamel organ of the CSG constructs.