Development of a chitosan-based tissue-engineered renal proximal tubule conduit

Renal proximal tubule cells (RPTCs) are responsible for glomerular filtration and maintenance of water/electrolyte balance. To regenerate a proximal tubule, sufficient cell numbers and normal cell function are requisite. Collagen has been routinely used as a substrate for culturing human RPTCs (HRPTCs); however, the role of biomaterials has not been thoroughly explored. In this study, RPTCs retrieved from human nephrectomy/nephroureterectomy specimens were cultivated on chitosan as a substrate in serum-free condition for up to 150 days. HRPTCs could maintain a typical epithelial morphology and the specific differentiation feature of transporting epithelia after such long-term culture. As compared with HRPTCs cultivated on collagen, those cultivated on chitosan showed more dome formation, higher Na⁺ -K⁺ ATPase expression, lower vimentin expression, and lower transepithelial electrical resistance, indicating that HRPTCs cultivated on chitosan presented better differentiation status and would be more functional with better active transportation. Thus, the current study indicates greater scope for the use of chitosan as a biomaterial for preparing a HRPTC-coated chitosan conduit, which might be useful for the scaffold design of tissue-engineered proximal tubules. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 9-20, 2018.