Fig. 3
From: Solid organ fabrication: comparison of decellularization to 3D bioprinting
3D bioprinting of complex solid organs and biomimetic 4D printing. a A single section showing collagen type IV immunofluorescence staining in a postnatal day 2 ventricle. The stack of images was used to create a 3D reconstruction of the collagen type IV labeled serial sections and a solid stereolithography rendering was generated from the stack of 20 serial sections. Multi-photon excitation-based fabrication was then used to create a 3D construction, V indicates blood vessel [3]. Confocal images of fibronectin immunofluorescence staining from mouse ventricle and the fabricated structure created through modulated raster scanning, with permission from the Optical Society [35]. A blood vessel was indicated by the arrow. b An explanted embryonic chicken heart was stained for fibronectin (green), nuclei (blue), and F-actin (red). A cross-section of the fluorescence alginate (green) scaffold was printed from the 3D CAD model of the embryonic heart with the internal trabeculation utilizing the FRESH technology, with permission from the American Association of the Advancement of Science [46]. c 4D printing pathways [69]; mathematical surface was generated from natural inspiration and the path was printed with hydrogel composite ink of cellulose fibrils. Anisotropic swelling of the composite ink transformed the printed 2D paths into a 3D structure