Keio University School of Medicine, Japan
Hiroshi Yagi has completed his MD at the age of 24 years and afterwards, completed surgical residency both from Keio University. He also has completed his Ph.D. at 32 from Keio University and postdoctoral studies from Massachusetts General Hospital, Boston. He is a hepatobiliary/ pancreas and transplant surgeon as well as a member of national research project for regenerative medicine. He has published more than 20 papers and serving as an editorial board member of Organogenesis.
There is a need for new methods to promote recovery from organ failure and regenerative medicine is an option that should be considered. Recent approaches using synthetic scaff olds and decellularized tissue have achieved a more complex level of tissue organization in organs with some success in clinical trials. In this context, the concept of decellularization technology has been applied to produce whole organ-derived scaff olds by removing cellular content while retaining all the necessary vascular and structural cues of the native organ. And there is an urgent need to fi nd its feasibility of human scale-up and biological alterations of the scaff old after implantation. Our recent study revealed that the decellularization technology could be applied in a large animal model to develop a transplantable engineered liver graft . Decellularized liver scaff old was generated by the similar protocol as we did in rats, connecting to portal vein for infl ow and inferior vena cava for outfl ow by surgical anastomosis. Anti-coagulants and antibiotics were applied prior to and during the surgery to prevent coagulation in the matrix scaff old and infection after transplantation. As a result, the large-scale liver scaff old was successfully transplanted in porcine body by vessel anastomosis without any leakage through day 10. Histological study revealed massive adhesion with infi ltration of inflammatory cells including lymphocytes and fibroblasts, and the coagulation was not totally avoided in the transplanted graft . However, the graft was preserved in the porcine abdominal cavity without bleeding or absorption. Although it requires improvement and customization with regard to anti-coagulation and further applicable cell sources, we could scale-up and optimize the system to apply this unique technology for clinical applications.