Abstract
For chronic kidney diseases, there is little chance that the vast majority of world's population will have access to renal replacement therapy with dialysis or transplantation. Tissue engineering would help to address this shortcoming by regeneration of damaged kidney using naturally occurring scaffolds seeded with precursor renal cells. The aims of the present study were to optimize the production of three-dimensional (3D) rat whole-kidney scaffolds by shortening the duration of organ decellularization process using detergents that avoid nonionic compounds, to investigate integrity of extracellular matrix (ECM) structure and to enhance the efficacy of scaffold cellularization using physiological perfusion method. Intact rat kidneys were successfully decellularized after 17 h perfusion with sodium dodecyl sulfate. The whole-kidney scaffolds preserved the 3D architecture of blood vessels, glomeruli, and tubuli as shown by transmission and scanning electron microscopy. Micro-computerized tomography (micro-CT) scan confirmed integrity, patency, and connection of the vascular network. Collagen IV, laminin, and fibronectin staining of decellularized scaffolds were similar to those of native kidney tissues. After infusion of whole-kidney scaffolds with murine embryonic stem (mES) cells through the renal artery, and pressure-controlled perfusion with recirculating cell medium for 24 and 72 h, seeded cells were almost completely retained into the organ and uniformly distributed in the vascular network and glomerular capillaries without major signs of apoptosis. Occasionally, mES cells reached peritubular capillary and tubular compartment. We observed the loss of cell pluripotency and the start of differentiation toward meso-endodermal lineage. Our findings indicate that, with the proposed optimized protocol, rat kidneys can be efficiently decellularized to produce renal ECM scaffolds in a relatively short time, and rapid recellularization of vascular structures and glomeruli. This experimental setup may open the possibility to obtain differentiation of stem cells with long lasting in vitro perfusion.