TABLE 4.

Vascularization of organoids in vitro.

Category	Report year	Methods	Organoids	Results
Co-culture	2018	Re-embed with endothelial cells	Brain organoids	Continuity of CD31-positive blood vessels inside the organoids Pham et al. (2018)
	2019	Co-culture with endogenous endothelial cells	Adipose tissue-like organoids	Connected to the recipient circulatory system Muller et al. (2019)
	2019	Vascular endothelial growth factor induction	Cerebral organoids	Vessel-like structures and blood–brain barrier characteristics Ham et al. (2020)
	2020	Co-culture with human umbilical vein endothelial cells	Cortical organoids	A well-developed mesh-like or tube-like vascular system Shi et al. (2020b)
	2021	Fusion with microvascular fragments	Islet organoids	Interconnection with surrounding blood vessels and restoration of normoglycemia Nalbach et al. (2021)
	2021	Fusion with microvascular fragments	Adipocyte organoids	Fabricate functional, vascularized, adipose-like organoids Strobel et al. (2021)
Organoids-on-a-chip	2019	Novel microphysiological platform	Retinal organoids	Vasculature-like perfusion and mature photoreceptor segments Achberger et al. (2019)
	2019	Culture underflow on millifluidic chips	Kidney organoids	Vascular network and enhanced cellular polarity and adult gene expression Homan et al. (2019)
	2020	A microfluidic platform named IFlowPlate	Colon organoids	A self-assembled vascular network and innate immune function Rajasekar et al. (2020)
Gene editing	2019	Ectopically express human ETS variant 2	Brain organoids	Vasculature-like structures and blood–brain barrier characteristics Cakir et al. (2019)
	2021	Overexpression of PROX1 and ATF5	Liver organoids	Vascular morphogenesis and improves native liver functions Velazquez et al. (2021)