Enhanced Kidney Targeting and Distribution of Tubuloids During Normothermic Perfusion

Tubuloids have become a promising tool for modeling and regenerating kidney disease, although their ability for integration and regeneration in vivo is not well documented. Here, we established, characterized, and compared human tubuloids using two optimized protocols: one involving prior isolation of tubular cells (Crude tubuloids) and the other involving prior isolation of proximal tubular cells (F4 tubuloids). Next, healthy rat-derived tubuloids were established using this protocol. Finally, we compared two strategies for delivering GFP tubuloids to a kidney host: 1) subcapsular/intracortical injection and 2) tubuloid infusion during normothermic preservation in a rat transplantation model and a discarded human kidney. F4 tubuloids achieved a higher level of differentiation state compared to Crude tubuloids. When analyzing tubuloid delivery to the kidney, normothermic perfusion was found to be more efficient than in vivo injection. Moreover, fully developed tubules were observed in the host parenchyma at 1 week and 1 month after infusion during normothermic perfusion represent a potential strategy to enhance the translatability of kidney regenerative therapies into clinical practice to condition kidney grafts and to treat kidney diseases.