Figure 3. Ultrastructural characterization of decellularized pancreas.

(A) Trypan blue dye infusion visualized the progressive flow from large vessels to the fine blood vessel branches along the channels without leakage. Inset shows light microscopy image of vasculature branches remained intact after decellularization. (B) TEM of decellularized pancreas depicted the intact basement membrane (arrowhead points to the underlying basement membrane). (C) TEM image of decellularized pancreas showed the interstitial space with organized fibers of collagen (arrowhead). (D–E) SEM comparison of native and decellularized pancreas demonstrated preservation of 3D microstructure of pancreatic duct after decellularization. Inset shows the absence of lining ciliated microvilli cells from the luminal surface of the duct after decellularization process. (F) SEM image of decellularized pancreas showed ECM fibers within the parenchymal space. (G) Higher magnification of 3D meshwork showed a variety of fibers - large bundle of Type I collagen (black arrowhead) associated with a variety of smaller fibers (white arrowhead). (H) SEM image of decellularized pancreas demonstrated large/small fibers interlinked in a plane that forms a boundary such as to previously occupied pancreatic parenchymal cells. (I) SEM image of decellularized pancreas demonstrated scalloping appearance of the internal elastic lamina of an artery, indicating intact blood vessel (BV).