Table 2.

Summary of case studies for microfluidic‐based vascularization strategies

Vascularization method		Organ/tissue model	Vessel caliber (d)/channel size (h × w)	Channel shape	Chip composition	Cellular composition	Perfusion parameters	Duration of in vitro study	In vivo evaluation/drug testing	Refs.
Soft lithography		Liver	100 µm × 1 mm	Rectangular, straight	PDMS; PE (polyester) membrane	LSECs, HCs, KCs, HSCs (all primary from mouse)	0.1 or 0.5 dynes cm−2, syringe pump	1 day	No/No	[ 73 ]
		BBB	Vascular channel: 800 µm, vascular network: <50 µm 35–100 µm	Rectangular, straight	PDMS; fibrin hydrogel PDMS; fibrin‐hyaluronic acid	HUVECs, lung fibroblasts, rat cortex neural cells Brain microvascular ECs; HUVECs; pericytes; astrocytes	–	7 days	No/No	[ 66 , 88 ]
		Kidney	0.2 × 1 mm (vascular), 1 × 1 mm (urinary)	Rectangular, straight	PDMS (chip, membrane)	Glomerular ECs; hIPS‐derived podocytes	0.017 dynes cm−2 (vascular), 0.0007 dynes cm−2 (urinary), peristaltic pump	8 days	No/Yes	[ 64 ]
		Intestine	0.15 × 1 mm	Rectangular, straight	PDMS (chip, membrane)	Capillary ECs or lymphatic microvascular ECs, Caco‐2 intestinal epithelial cells, immune cells	0.02 dynes cm−2	>7 days	No/Yes	[ 70 ]
		Multiorgan	(100 × 500 µm) to 40 µm	Rectangular, curved	PDMS	Dermal microvascular ECs	10–40 dynes cm−2, on‐chip micropump	Up to 4 weeks	No/No	[ 78 ]
Templating		Liver	300 µm (main channel) 100–1000 µm	Circular, straight Circular, curved, branched	Collagen I GelMA	HUVECs; hepatocytes (HepG2); MSCs HUVECs, hepatocytes (HepG2)	10−1 dynes cm−2, peristaltic pump 50 µL h−1, syringe pump	8 days 7 days	No/No No/Yes	[ 19 , 103 ]
		Skin	520 µm 100–250 µm	Circular Rectangular, curved, branched	Collagen I Collagen I	HUVECs, dermal fibroblasts, epidermal keratinocytes HUVECs, iPSC‐derived ECs, dermal fibroblasts, keratinocytes	2–3 mL h−1, peristaltic pump Syringe pump	10 days 21 days for cornification, 2 days at ALI	No/Yes Yes/No	[ 74 , 94 ]
		Heart	100–500 µm	Circular	Fibrin matrix	Neonatal rat heart cells mix	20 µL h−1, syringe pump	21 days	No/No	[ 93 ]
3D bioprinting		Urothelial/vascular tissue a)	≈700 µm (inner), ≈1 mm (outer)	Circular, multilayer, flexible	Bioink: PEGOA + GelMA	Urothelial: human urothelial cells + human bladder SMCs; vascular: HUVECs + human SMCs	–	14–21 days	No/No	[ 104 ]
		Kidney	200 µm	Circular, colocalized	Gelatin + fibrin ECM; bioink: pluronic F127 + PEO	Glomerular microvascular ECs; proximal tubule epithelial cells	0.3 dynes cm−2	18 days	No/Yes	[ 75 ]
		Heart	500 µm (200–900 µm)	Circular, hierarchical, multibranched	Agarose hydrogel, PCL network	Rat cardomiocytes	Syringe pump	5 days	Yes/No	[ 99 ]
		Vasculature a)	1.5 × 3 mm	Rectangular, straight	PMMA case, GelMA	Aortic ECs; aortic SMCs; fibroblasts	100 µL h−1, peristaltic pump	7 days	No/No	[ 105 ]
Alternative strategies	LbL	Liver/heart	100 × 50 to 100 µm	Rectangular, straight	POMaC, fibrin gel/Matrigel for parenchyma	Liver: HUVECs + hESC‐derived hepatocytes + hMSCs; heart: HUVECs + hESC‐derived CMs + hMSCs	0.6 dynes cm−2, bioreactor	7 days	Yes/Yes	[ 69 , 100 ]
	Laser‐based	–	<10 µm	Tortuous, dense	PEGDA	Mouse brain ECs	10 µL min−1	11 days	No/No	[ 101 ]
	Explanted vessels	Brain	120 µm	Circular, physiological	PDMS	ECs, SMCs	0.5 µL min−1, no external pump	–	No/Yes	[ 102 ]

^a) Bioinks containing cells.