Acellular scaffolds from decellularized donor organs are showing promising clinical results in tissue and organ repair and regeneration. A successful decellularization process is determined by (a) its capability to decellularize complete organs of large animals, (b) retention of the extracellular matrix (ECM) structures and morphologies, and (c) minimal loss of ECM proteins. In this study, porcine esophagi were perfused in full thickness with 0.25% w/v sodium dodecyl sulfate at perfusion rates 0.1–0.2 ml/min for up to 5 days. Decellularized tissues were characterized for their residual DNA, histological staining for their matrix structures, immunohistochemical staining for collagen type IV and laminin, and scanning electron microscopy for structural integrity. Our results showed that full thickness esophageal tissues treated using the horizontal perfusion setup were decellularized with good structural and biochemical integrity in the ECM. Residual DNA content in decellularized tissues was found to be 36 ± 12 ng/mg of tissues (n = 6) which was significantly lower than that of native tissues (p = .00022). Our study showed that the organ must be decellularized in full thickness and perfusion pressure must be controlled to minimize radial expansion. These factors were found to be critical in preserving the folded mucosa in the decellularized tissues.

Decellularization is the process of removing cellular components from native tissues or organs to obtain an acellular, collagenous scaffold for use in tissue engineering and organ regeneration. Surfactants are widely used to produce acellular scaffolds for clinical applications. However, cell–surfactants interactions have not been studied in depth. Cell-surfactant interaction was studied in a time-lapsed manner using sodium dodecyl sulfate (SDS) solution (surfactant) on adherent L929 fibroblasts as a test solution, phosphate-buffered saline (PBS) solution as control solution (isotonic), and deionized water as positive test solution (hypotonic), respectively. The QPI results show changes in the relative height and cross-sectional area of the cells, with various test solutions and exposure times. In particular, it was observed that the removal of the cell with SDS involved the disruption of the cellular membrane and detachment of the cell contents from the adhering surface. This study demonstrated the feasibility of using the QPI technique to understand the decellularization process.

Esophageal diseases necessitate the use of replacements or scaffolds to repair the esophagus. As porcine esophagus is structurally and biochemically similar to that of human's, decellularized porcine scaffold provides the potential for esophageal regeneration. This thesis focuses on the development of perfusion processes to decellularize porcine esophagi. The first part of the thesis evaluates on the decellularization process. Our objectives include producing scaffolds with preserved folded mucosa and basement membrane, retention of the structural extracellular matrices (ECM) and ECM proteins. Two important processing criteria found in our study were (1) full thickness esophagus must be used, and(2) the perfusion pressure must be controlled to minimize radial expansion. The vertical and the horizontal perfusion setups were compared. Vertically perfused scaffolds resulted in the unfolding of the mucosa, but for the horizontal process, the folded mucosa was preserved. Full decellularization of the native esophagus was achieved with 0.25% w/v sodium dodecyl sulfate (SDS) at perfusion rates 0.1-0.2 ml/min for up to 5 days. Both native and decellularized scaffolds were characterized and compared. Characterisations include histological examinations, optical and electron microscopy, and residual DNA analysis.The second part of this thesis focused on the scaffold cytotoxicity evaluated according to ISO 10993 Part 5, and in vitro cell-scaffold interaction. Our results showed that the metabolic activity of L929 fibroblasts cultured for 1,3, and 7 days in extracted culture medium and standard medium (negative control) were not statistically significant (i.e. P > .05). Cell-scaffolds interaction results showed that the scaffold supported proliferation of mammalian cells. Further study