Three-Dimensional Bioprinting of Hepatic Structures with Directly Converted Hepatocyte-Like Cells

Abstract

Three-dimensional (3D) bioprinting technology is a promising new technology in the field of bioartificial organ generation with regard to overcoming the limitations of organ supply. The cell source for bioprinting is very important. Here, we generated 3D hepatic scaffold with mouse-induced hepatocyte-like cells (miHeps), and investigated whether their function was improved after transplantation in vivo. To generate miHeps, mouse embryonic fibroblasts (MEFs) were transformed with pMX retroviruses individually expressing hepatic transcription factors Hnf4a and Foxa3. After 8-10 days, MEFs formed rapidly growing hepatocyte-like colonies. For 3D bioprinting, miHeps were mixed with a 3% alginate hydrogel and extruded by nozzle pressure. After 7 days, they were transplanted into the omentum of Jo2-treated NOD Scid gamma (NSG) mice as a liver damage model. Real-time polymerase chain reaction and immunofluorescence analyses were conducted to evaluate hepatic function. The 3D bioprinted hepatic scaffold (25 × 25 mm) expressed Albumin, and ASGR1 and HNF4a expression gradually increased for 28 days in vitro. When transplanted in vivo, the cells in the hepatic scaffold grew more and exhibited higher Albumin expression than in vitro scaffold. Therefore, combining 3D bioprinting with direct conversion technology appears to be an effective option for liver therapy.

Combining Stem Cells and Biomaterial Scaffolds for Constructing Tissues and Cell Delivery

“…The properties of alginate make it easy to bioprint. Accordingly, several different 3D bioprinted tissues have been produced using alginate bioinks in combination with stem cells, including neural tissue, cartilage, bone and liver [152][153][154][155]. This body of work shows that alginate serves as a highly desirable material for engineering a wide variety of tissues due to its unique properties.…”

Liver Tissue Engineering as an Emerging Alternative for Liver Disease Treatment

“…Albumin, ASGR, and HNF4a expression increased for 28 days in vitro and transplanting the scaffold in vivo showed higher albumin secretion. 97 Wang et al used a 3D micropositioning system to print a mixture of gelatin and rat hepatocytes with a resolution of 10 mm and could preserve the viability of cells more than 2 months. 159 In a study, it has been shown that increasing the feed and pressure decreases the strut width in a 3D cell printing technology using natural ECM as the bioink.…”

Bioprinting for Liver Transplantation

“…The main goal of this study was to create hepatocyte cell culture networks which demonstrated a high viability of the cells after 14 days with good hepatic functionality [75]. The same year, Kang et al [139] used mouse-induced hepatocyte-like cells (miHeps) by pluripotent stem cells (PSC) for the development of a 3D structure made by miHeps and aginate using extrusion printing. Five layers of cells and alginate printing solution built the final 3D cell culture which was placed in a mouse in vivo.…”