Oxygenated Perfusion Enhances Hepatocyte Function in Human iPSC-liver Tissue

Background. Organ transplantation remains the only curative treatment for end-stage organ failure. However, a critical shortage of donor organs presents a major challenge. Human induced pluripotent stem cell (hiPSC)-derived organoids represent a promising technology for generating transplantable human tissues. This study aimed to create functional and scalable tissue from hiPSC-derived liver organoids (hiPSC-LOs) by establishing an oxygenation system using a decellularized liver (DL), which retains the parenchymal and vascular extracellular matrix to support cell adhesion and medium perfusion. Methods. First, the culture condition of hiPSC-LOs was refined to enhance their engraftment in rat DLs. Next, an oxygenation system for hiPSC-LO-engrafted DLs (hiPSC-liver tissue [hiPSC-LT]) was established using perfusion of oxygen-enriched medium containing artificial red blood cells. Finally, the oxygenated hiPSC-LTs were transplanted onto the liver surface of immunodeficient mice. Results. Functional hiPSC-LTs were successfully generated by infusing day 8 precultured hiPSC-LOs into DLs. Perfusion with oxygenated medium containing artificial red blood cells suppressed cell death and promoted hepatic function of hiPSC-LTs by mimicking the physiological oxygen concentration found in the fetal liver. Notably, oxygenated hiPSC-LTs demonstrated improved engraftment in vivo, as evidenced by increased human albumin levels in recipient mouse serum compared with nonoxygenated controls. Conclusions. The oxygenation system using DLs and artificial red blood cells effectively supported the generation of transplantable, functional hiPSC-LT. This culture strategy enhances both the enlargement and functionality of hiPSC-organoids and represents a promising step toward developing alternatives to conventional organ transplantation.