Table 2.

Up-to-date methods for obtaining expandable human liver organoids

Initial cells	Expansion systems (substrate for embedding)	Medium	Expansion capability (Split ratio/passage days/expansion duration)	Ref.
Fetal and adult hepatocytes	3D, Matrigel	AdDMEM/F12, B27, N-Acetylcysteine, gastrin, RSPO1, Noggin, Wnt, EGF, FGF7, FGF10, HGF, TGFa, Nicotinamide, A83-01, CHIR99021 and Y27632	1:3/7-8 d/> 16 passages	2018[70]
EpCAM+ bile duct cells	3D, Matrigel or BME gel	AdDMEM/F12, N2, B27, N-Acetylcysteine, gastrin, RSPO1, Noggin (d0-3), Wnt (d0-3), EGF, FGF10, FGF19, HGF, Nicotinamide, A83-01, FSK, and Y27632 (d0-3)	1:4-1:8/7-10 d/6 mo	2015[69]
EpCAM+ bile duct cells	3D, BME gel	AdDMEM/F12, B27, N-Acetylcysteine, gastrin, RSPO1, Noggin (d0-3), Wnt (d0-3), EGF, FGF10, FGF19, HGF, Nicotinamide, A83-01, FSK, and Y27632 (d0-3)	1:5/7-10 d/> 6 mo	2019[107]
iPSC derived EpCAM+ hepatic progenitors	3D, Matrigel	AdDMEM/F12, B27, N-Acetylcysteine, gastrin, RSPO1, Noggin (d0-3), Wnt (d0-3), EGF, FGF10, HGF, Nicotinamide, A83-01, FSK and Y27632 (d0-3)	1:4-1:8/7-10 d/9-12 mo	2019[71]
PSC-derived hepatocytes	3D, Matrigel	AdDMEM/F12, N2, B27, N-Acetylcysteine, gastrin, RSPO1, EGF, FGF10, HGF, Nicotinamide, A83-01, FSK	1:3-1:10/7 d/3 mo	2019[72]
PSCs transduced with PROX1, ATF5 and CYP3A4	3D, Matrigel	APEL medium	NA/10 d/17 d	2021[66]

APEL: A commercial medium from Stem Cell Technologies; BME: Basement membrane extract; bFGF: Basic fibroblast growth factor; BME: Basement membrane extract; EGF: Epidermal growth factor; FGF: Fibroblast growth factor; FSK: Forskolin; HGF: Hepatocyte growth factor; iPSCs: Induced pluripotent stem cells; PSCs: Including embryonic stem cells and induced pluripotent stem cells; RSPO1: R-spodin1.