Generation of a vascularized and functional human liver from an iPSC-derived organ bud transplant

Abstract

Generation of functional and vascularized organs from human induced pluripotent stem cells (iPSCs) will facilitate our understanding of human developmental biology and disease modeling, hopefully offering a drug-screening platform and providing novel therapies against end-stage organ failure. Here we describe a protocol for the in vitro generation of a 3D liver bud from human iPSC cultures and the monitoring of further hepatic maturation after transplantation at various ectopic sites. iPSC-derived specified hepatic cells are dissociated and suspended with endothelial cells and mesenchymal stem cells. These mixed cells are then plated onto a presolidified matrix, and they form a 3D spherical tissue mass termed a liver bud (iPSC-LB) in 1-2 d. To facilitate additional maturation, 4-d-old iPSC-LBs are transplanted in the immunodeficient mouse. Live imaging has identified functional blood perfusion into the preformed human vascular networks. Functional analyses show the appearance of multiple hepatic functions in a chronological manner in vivo.