Stem Cell Technology in Organ Transplantation: A Novel Method for 3D Bioprinting Functional and Stable Liver Grafts Using Human iPS Cells Derived Cells.

For decades, scientists and physicians aim to generate functional human tissues in the laboratory using stem cells. In this section, we will describe a novel method that combines state-of-the-art stem cell culture with 3D bioprinting to generate potentially transplantable tissue grafts. For this purpose, we will use the liver as a model. The liver is an important metabolic hub and responsible to perform many endocrine and exocrine vital functions. It is estimated that two million deaths/year are associated with liver disease. This illustrates the need for developing new efficient alternatives for liver transplantation. Modern 3D bioprinting technologies in combination with autologous induced pluripotent stem cells (iPS)-derived grafts could represent a relevant tissue engineering approach to treat end-stage liver disease. Here, we described a novel method for 3D bioprinting functional and stable liver grafts using human iPS-derived cells. The novel method described in this section uses the hepatocyte-like cells in a spheroid culture format (i.e., obtained from three-dimensional cell culture), in combination or not with non-parenchymal cells (e.g., mesenchymal and endothelial cells), which generates the final liver graft. This method has proved to sustain epithelial phenotype and to increase the stability and functionality of the constructs for prolonged periods.