Recellularization of Decellularized Whole Organ Scaffolds: Elements, Progresses, and Challenges

Organ transplantation is considered as the gold standard treatment for end-stage organ failure. Because of the severe shortage of donor organs, tremendous efforts, including whole organ engineering, have been made to construct biological substitutes to restore the function of diseased or injured organs. In the field of whole organ engineering, seed cells, acellular whole organ scaffolds, and recellularization strategies make up the essential elements. Both differentiated and stem cells, either autologous or allogenic, have been utilized in the proof-of-concept exploration of whole organ engineering. Based on the encouraging achievements made in the clinical application of decellularized extracellular matrix materials for various diseases, decellularized whole organ scaffolds are proposed as the ideal candidate for whole organ engineering, featuring a beneficial organ-specific microenvironment for seed cells, as well as an intact vasculature for subsequent supply of oxygen and nutrients. These merits of acellular whole organ scaffolds are too sophisticated to mimic artificially. After proper delivery of essential parenchymal and non-parenchymal cells, and following the necessary in vitro bioreactor-based culture to allow the seed cells to proliferate, differentiate, and mature within the scaffolds, bioengineered organs are promising for eventual transplantation. This chapter aims to provide an overview of the recellularization of decellularized whole organ scaffolds, with a focus on the basic elements, current research progresses, and future challenges.