Supplementary Figure 4: Electron microscopic characterization of ex vivo colon mucosa.

(A) Scanning electron micrographs of mucosa surface, lamina propria and muscularis mucosa show that crypt niches were retained and intestinal fibers were well preserved in composition and ultrastructure during the de-/re-cellularization process. White arrows denote crypt niches; characteristic weaves (W), coils (C) and struts (S) of colonic fibers of laminin and collagen are present in both decellularized and recellularized matrices. Scale bars, 20 µM. (B) Transmission electron micrographs reveal the continuous intactness of muscularis mucosa (MM) layers in both decellularized matrix and recellularized tissue. |<->| designates the location and thickness of MM layers that were repopulated with fibroblasts (<-) in recellularized colon. Features: collagen fibers (\/); lamina filaments (<-). M, mucosa area; SM, submucosal area; scale bars, 500 nM (300 nM in small windows). All of the recellularized tissues have been cultured for 6-7 weeks when they are processed for electron microscopy. (C) No statistical differences in MM thickness were observed among native, recellularized and recellularized colon tissues. Error bars indicate S.E.M. (n= 6 of independent matrix; difference analysis by one-way ANOVA).