An improved method of renal tissue engineering, by combining renal dissociation and reaggregation with a low-volume culture technique, results in development of engineered kidneys complete with loops of Henle.

Background: Tissue engineering of functional kidney tissue is an important goal for clinical restoration of renal function in patients damaged by infectious, toxicological, or genetic disease. One promising approach is the use of the self-organizing abilities of embryonic kidney cells to arrange themselves, from a simply reaggregated cell suspension, into engineered organs similar to fetal kidneys. The previous state-of-the-art method for this results in the formation of a branched collecting duct tree, immature nephrons (S-shaped bodies) beside and connected to it, and supportive stroma. It does not, though, result in the significant formation of morphologically detectable loops of Henle - anatomical features of the nephron that are critical to physiological function.

Methods: We have combined the best existing technique for renal tissue engineering from cell suspensions with a low-volume culture technique that allows intact kidney rudiments to make loops of Henle to test whether engineered kidneys can produce these loops.

Results: The result is the formation of loops of Henle in engineered cultured 'fetal kidneys', very similar in both morphology and in number to those formed by intact organ rudiments.

Conclusion: This brings the engineering technique one important step closer to production of a fully realistic organ.