In vitro induction and in vivo engraftment of kidney organoids derived from human pluripotent stem cells

The shortage of transplantable organs impedes the development of tissue-engineered alternatives. Producing tissues similar to immature kidneys from pluripotent stem cells is possible in vitro, but the size of the organoids is limited. Furthermore, in vivo implantation is necessary for organoid development and functional maturation. In the present study, the induction procedure was optimized and kidney organoids derived from induced pluripotent stem cells in vitro were produced. The kidney organoids were examined by immunofluorescence and quantitative PCR. Then, a unilateral nephrectomy model was established that was beneficial to the compensatory proliferation of the other kidney. Finally, these organoids were implanted below the kidney capsules of immunodeficient mouse hosts that had been nephrectomized unilaterally. This implantation resulted in the enlargement of the organoids and the production of vascular cells. Although signs of organoid maturation were lacking in short-term culture in vivo, the present study provided a method for studying kidney organoid development in vivo.