TABLE I.

Summary of classification and features of developed BoCs.

Type of BoC	Features	Applications	Reference
(A) 2D BoC for axon isolation	•Fabrication of different height channels in one BoC •Separation of soma and axon	Axon-specific drug testing	22 and 23
		Axon regeneration after axotomy	24
		Unidirectional axonal growth	25 and 26
		Myelination on the axon	28–30
(B) BoC with porous membrane	•Porous membrane between two microchannels •Interaction between two different type of cells through the pores	Cell–cell communication via cytokine-mediated manners	33 and 34
		Cell–cell communication via direct contact	36
		Measure of transendothelial electrical resistance	35
(C) 3D high-content BoC with hydrogel	•3D culture of multiple types of cells within the hydrogel •In vivo-like microenvironment	3D neural circuit formation	39 and 40
		Recapitulation of 3D BBB structure and functions	41–45
(D) Interconnected BoC system	•Linking of individually fabricated BoCs •Interactions among the various BoCs	Interactions of various cells of neurovascular unit	46
		Interactions between brain and other organs	47 and 48
(E) BoC integrated with well plate	•Compatibility with conventional labwares (e.g., 96-well plate) •High-throughput analysis available	Compatibility with traditional cell-culture platforms	50–52
		Imaging of BoC in a high-throughput manner	55–57