Self-assembly of renal cells into engineered renal tissues in collagen/Matrigel scaffold in vitro.

To tissue engineer a kidney is a formidable task because of the complex cell composition and structures in the kidney. This study reconstructed renal tissues using mixed renal cells in collagen/Matrigel® scaffolds in vitro. Neonatal rat renal cells were seeded in collagen I supplemented with Matrigel in a casting mold that could exert static stretch when the renal constructs contracted. During in vitro culture, the renal constructs were observed under microscope and analyzed by histological and immunofluorescent examinations. Results showed that the mixed renal cells reconstituted renal tubular and glomeruli-like structures with different appearances at varying developmental stages. Tubular structures were formed by CK18-positive cells with similar appearances lining the surrounding hollow centres. The glomeruli-like structures were tufts of cell aggregates containing Flk-1-positive cells. These results show that neonatal rat renal cells self-assembled into engineered renal tissues containing both tubules and glomeruli-like structures when cultured in 3D collagen/Matrigel scaffold in vitro.