Chapters authored
Optimization of a Decellularization/Recellularization Strategy for Transplantable Bioengineered Liver
The liver is a complex organ that requires constant perfusion for the delivery of nutrients and oxygen and the removal of waste in order to survive. Efforts to recreate or mimic the liver microstructure via a ground-up approach are essential for liver tissue engineering. A decellularization/recellularization strategy is one of the approaches aiming at the possibility of producing a fully functional organ with in vitro-developed construction for clinical applications to replace failed livers, such as end-stage liver disease (ESLD). However, the complexity of the liver microarchitecture along with the limited suitable hepatic component, such as the optimization of the extracellular matrix (ECM) of the biomaterials, the selection of the seed cells, and development of the liver-specific three-dimensional (3D) niche settings, pose numerous challenges. In this chapter, we have provided a comprehensive outlook on how the physiological, pathological, and spatiotemporal aspects of these drawbacks can be turned into the current challenges in the field, and put forward a few techniques with the potential to address these challenges, mainly focusing on a decellularization-based liver regeneration strategy. We hypothesize the primary concepts necessary for constructing tissue-engineered liver organs based on either an intact (from a naïve liver) or a partial (from a pretreated liver) structure via simulating the natural development and regenerative processes.
Part of the book: Xenotransplantation
Survival Fate of Hepatic Stem/Progenitor and Immune Cells in a Liver Fibrosis/Cirrhosis Animal Model and Clinical Implications
This chapter provides novel information about the survival features of hepatic resident stem/progenitor cells (NG2+ HSPs) during liver fibrosis/cirrhotic development. A well-defined diethylnitrosamine (DEN)-induced liver fibrosis/cirrhotic/cancer mouse model was developed to evaluate the fate of the HSPs and its clinical implications. This model possess three time-zones during the disease development: fibrosis (3–5 weeks post-DEN), cirrhosis (6–10 weeks post-DEN), and cancers (up to 10 weeks post-DEN). During this process, the model represents histological patterns similar to those described in humans and shows better survival of the HSPs in the fibrotic zone, which was correlated with inflammatory signals, as compared to the cirrhotic zone. It has also been discovered that immune CD8+ T cells in the fibrotic zone are beneficial in liver fibrosis resolution, suggesting that the fibrotic time zone is important for mobilizing endogenous HSPs and cell-based therapy. As such, we hypothesize that clinical strategies in fibrotic/cirrhotic liver treatment are necessary either in time at the fibrotic phase or to adopt an approach of regulating HSP viability when the disease develops into the cirrhotic phase.
Part of the book: Animal Models and Experimental Research in Medicine