Efficient decellularization of whole porcine kidneys improves reseeded cell behavior

Combining patient-specific cells with the appropriate scaffold to create functional kidneys is a promising technology to provide immunocompatible kidneys for the 100 000+ patients on the organ waiting list. For proper recellularization to occur, the scaffold must possess the critical microstructure and an intact vascular network. Detergent perfusion through the vasculature of a kidney is the preferred method of decellularization; however, harsh detergents could be damaging to the microstructure of the renal tissue and may undesirably solubilize the endogenous growth and signaling factors. In this study, automated decellularization of whole porcine kidneys was performed using an improved method that combined physical and chemical steps to efficiently remove cellular materials while producing minimal damage to the collagenous extracellular matrix (ECM). Freezing/thawing, incremental increases in flow rate under constant pressure, applying osmotic shock to the cellular membranes, and low concentrations of the detergent sodium dodecyl sulfate (SDS) were factors used to decrease SDS exposure time during the decellularization process from 36 to 5 h, which preserved the microstructure while still removing 99% of the DNA. The well-preserved glycosaminoglycans (GAGs) and collagen fibers enhanced cell-ECM interactions. Human renal cortical tubular epithelium (RCTE) cells grew more rapidly when cultured on the ECM obtained from the improved decellularization process and also demonstrated more in vivo-like gene expression patterns. The optimized, automated process that resulted from this work is now used routinely in our laboratory to rapidly decellularize porcine kidneys and could be adapted to other large organs (e.g. heart, liver, and lung).