Fig. 7: Examples of 3D printed hydrogel constructs.

a 3D model of the multiacini design with representative 2D slices of the construct displayed. b Photograph of the 3D bioprinted construct immersed in water, with the cavity filled with blue dye for visualization. Scale bar: \(1{mm}\). The top view highlights the acinar cavity feature. Scale bar: \(2{mm}\). c Schematic illustration of a resin container showing the appearance of transparent resin compared to a cell-laden hydrogel solution. Light scattering induced by suspended cells within the hydrogel is illustrated. d Illustration of the bioprinted construct after printing, showing embedded human fibroblasts distributed around the multiacinar cavity. (i.) Image of the resin container before printing using transparent resin, captured with inspection camera 1. Scale bar: 500μm. (ii.) Image of the resin container before printing using cell-laden hydrogel, captured with inspection camera 1. Scale bar: 500μm. e–h Representative fluorescence confocal images of the bioprinted constructs showing fibroblast networks surrounding the multiacinar cavities. The hydrogels were printed using a laser power output of 55 mW with a printing time of 52 s. e Confocal slices corresponding to the inlet region at the top surface of the construct, with nuclei stained in blue (i) and F-actin in green (ii). Scale bars: \(500\,\mu m\). f Magnified view of the region indicated by the square in (e). Scale bar: \(200\,\mu m\). g confocal slices corresponding to the central region of the construct containing the acinar cavities, with nuclei shown in blue (i) and F-actin in green (ii). Scale bars: 2\(00\,\mu m\). h Three-dimensional reconstruction of multiple confocal slices highlighting the fibroblast network, with F-actin shown in green along the z-axis. Scale bar: \(200\,\mu m\)