TABLE I.

Overview of barrier assessment techniques in organ-on-a-chip systems.

Organ	Assessment	Co-culture	Culturing type	References
Blood-brain Barrier	TEER	No	2D	41 and 46
Blood-brain Barrier	PTT	No	2D	60 and 55
Blood-brain Barrier	PTT	Yes	2D	56 and 67
Blood-brain Barrier	PTT	Yes	3D	57 and 56
Blood-brain Barrier	PTT	No	3D	57
Blood-brain Barrier	TEER	Yes	2D	58
Blood-brain Barrier	TEER, PTT	Yes	2D	36, 46, 59, and 60
Blood-brain Barrier	TEER, PTT	Yes	3D	41, 61, and 62
Cornea	PTT	No	2D	63
Gastrointestinal Tract	PTT	Yes	2D	64 and 65
Gastrointestinal Tract	TEER	Yes	2D	66
Gut	TEER, PTT	No	2D	6
Kidney	TEER, PTT	Yes	2D	38
Liver	PTT	No	2D	67
Lung	TEER, PTT	Yes	2D	5
Lung	PTT	Yes	2D	68
Retina	PTT	Yes	2D	69
Retina	PTT	Yes	3D	70
Vasculature	PTT	No	3D	53 and 71
Multiple organs	TEER	Yes	2D	72
Multiple organs	TEER, PTT	Yes	2D	46