Design by Nature: Emerging Applications of Native Liver Extracellular Matrix for Cholangiocyte Organoid-Based Regenerative Medicine

Abstract

Organoid technology holds great promise for regenerative medicine. Recent studies show feasibility for bile duct tissue repair in humans by successfully transplanting cholangiocyte organoids in liver grafts during perfusion. Large-scale expansion of cholangiocytes is essential for extending these regenerative medicine applications. Human cholangiocyte organoids have a high and stable proliferation capacity, making them an attractive source of cholangiocytes. Commercially available basement membrane extract (BME) is used to expand the organoids. BME allows the cells to self-organize into 3D structures and stimulates cell proliferation. However, the use of BME is limiting the clinical applications of the organoids. There is a need for alternative tissue-specific and clinically relevant culture substrates capable of supporting organoid proliferation. Hydrogels prepared from decellularized and solubilized native livers are an attractive alternative for BME. These hydrogels can be used for the culture and expansion of cholangiocyte organoids in a clinically relevant manner. Moreover, the liver-derived hydrogels retain tissue-specific aspects of the extracellular microenvironment. They are composed of a complex mixture of bioactive and biodegradable extracellular matrix (ECM) components and can support the growth of various hepatobiliary cells. In this review, we provide an overview of the clinical potential of native liver ECM-based hydrogels for applications with human cholangiocyte organoids. We discuss the current limitations of BME for the clinical applications of organoids and how native ECM hydrogels can potentially overcome these problems in an effort to unlock the full regenerative clinical potential of the organoids.

Scalable Production of Size-Controlled Cholangiocyte and Cholangiocarcinoma Organoids within Liver Extracellular Matrix-Containing Microcapsules

“…Alternative (synthetic) ECM components, such as collagen [ 14 ], cell adhesion motifs (fibronectin or RGD) [ 32 ], or laminin-111 [ 15 , 33 ], can be used to augment the inert polymeric backbone and to create a more tissue-mimetic or tumor surrounding [ 8 , 14 , 34 ]. These components were considered, but fine-tuning and optimizing the concentrations in designer hydrogels with ECM components can be cumbersome and challenging [ 13 ]. Alternatively, ECM extracts from decellularized tissues can be used [ 35 ].…”

“…Human cholangiocyte organoids are of interest for regenerative applications, such as ex vivo repair of the damaged biliary epithelium [ 6 , 13 ]. Although not pursued in the current study, the high-throughput nature of the organoid production technique might be beneficiary for the clinical translation of ICO for tissue engineering applications.…”

“…Organoids are typically cultured in BME, which is a complex mixture of extracellular matrix (ECM) components derived from the mouse tumor mass produced by Englebreth-Holm-Swarm cells [ 11 , 12 ]. BME allows for self-organization of the cells into three-dimensional organotypic structures with maintenance of a proliferative status and can be used to create a tumor tissue-like microenvironment in vitro [ 5 , 13 , 14 , 15 ]. However, the process of cellular self-organization is uncontrolled, leading to relatively large inter-organoid disparity in size [ 16 ].…”

“…We have recently shown that BME can be replaced by a hydrogel derived from decellularized human liver ECM [ 21 ]. This hydrogel supports the initiation and culture of cholangiocyte organoids and can unlock direct clinical applications for regenerative medicine purposes [ 13 ]. However, the use of this hydrogel does not resolve the high level of heterogeneity in organoid size and culture and still requires a time-consuming process.…”

Advances of Engineered Hydrogel Organoids within the Stem Cell Field: A Systematic Review

“…Micromachining, 3D printing, and hydrogels are the basic elements of 3D cell culture techniques [ 1 ]. Various 3D culture methods for different tissues have been developed in recent years, which laid a solid foundation for the development of organoid culture techniques [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Stem-cell-derived organoids are in vitro organ models that form functional tissue types by self-organization and differentiation, which can potentially facilitate a better understanding of the biology and physiology of various organs [ 10 ].…”