Enhanced Kidney Targeting and Distribution of Tubuloids During Normothermic Perfusion
Tubuloids have become a promising tool for kidney disease model and regeneration, although their ability for integration and regeneration in vivo is not well documented. Here we establish, characterize and compare human tubuloids using two optimized protocols, which added a prior isolation of tubular cells (Crude tubuloids) and proximal tubular cells (F4 tubuloids). Secondly, using this protocol, healthy rat-derived tubuloids were established. Finally, we compared two strategies to deliver GFP tubuloids in a kidney host: 1) subcapsular/intracortical injection and 2) tubuloid infusion during normothermic preservation in a rat transplantation model and a human discarded kidney. F4 tubuloids achieved a more differentiation state compared to Crude tubuloids. When analyzing tubuloid delivery to the kidney, normothermic perfusion was more efficient compared to in vivo injection, observing fully-developed tubules in the host parenchyma after 1 week and 1 month. Normothermic perfusion also successfully delivered kidney tubuloids to a discarded human kidney for transplantation. These results suggest that tubuloids administered during normothermic perfusion represent a potential strategy to enhance the translatability of kidney regenerative therapies to the clinical practice to condition kidney grafts and to treat kidney diseases.