Table 2.

Summary of in vitro studies involving co-culture of ASCs and endothelial cells to promote vascularization.

EC Type	Source of ASC	Authors	Details and Effect on Vessel Formation
HUVEC	Human	[8]	Culturing of fibrin-embedded spheroids induced organization into prevascular-like structures expressing CD34 and α-SMA.
OEC	Human	[72]	Induced formation of CD31-positive branching vessel structures in a fibrin matrix. Expression of MMP-14 in the invading sprouts. Elevated VEGF secretion.
HUVEC	Human	[75]	Improved capillary network formation and expression of CD31, vWf, VEGF and MMPs in HA/gelatin gel. Enhanced vascularization in a 3D-printed composite scaffold.
AT-EC	Human	[10]	Vascular network with continuous endothelial lumen formation.
HUVEC	Human	[76]	Induced formation of vessel-like structures on Thermanox (2D) and in collagen gel (3D).
BEC + LEC	Human	[77]	In a triculture in fibrin gel, LEC and BEC form separate networks, which are dependent on ASC contact. Lymphatic network is dependent on VEGF-C.
HUVEC, rat LMEC	Rat	[78]	Improved tubulogenesis in Matrigel. Upregulation of VEGF, Ang-2, VEGFR2 and Tie-2 in HUVECs.
EPC, HUVEC	Human	[21]	Increased VEGF secretion and formation of capillary-like structures with longer sprouts in ASC/EPC co-culture but not in ASC/HUVEC co-culture. Blockade of VEGFR2 inhibits capillary-like structure formation.
HUVEC	Human	[79]	Enhanced calcium deposition and secretion of BMP-2 and VEGF, which were further increased by electrical stimulation.
CBD-EC	Human	[9]	The co-culture induces activin A expression in ASCs and secretes lower levels of angiogenic factors compared with ASC culture.
HMEC	Human	[80]	Improved capillary network by osteodifferentiating ASCs. ECs enhance the production of VEGF, PDGF-B and FGF-2 in osteodifferentiating ASCs.
HUVEC, OEC	Human	[69]	Proximity of ASCs required for mature network formation in fibrin gel. ASCs induce and stabilize EC networks by developing pericyte characteristics and by protein secretion.
HUVEC	Human	[70]	Induced network formation and deposition of basal lamina components in a co-culture in fibrin. ASCs differentiate toward a pericyte phenotype.
HUVEC	Human	[73]	ASCs show pericyte-like behavior and differentiation into ECs in a co-culture over a porous membrane.
HUVEC	Human	[74]	ASCs exhibit EC-like phenotype in a co-culture in nitric-oxide-releasing gel. Increased sprouting in the beginning of cultures.
HAMEC, HUVEC	Human	[22]	HAMEC/ASC co-culture induces the most organized and complex vascular network expressing CD31 and α-SMA in a 3D scaffold.
Mouse BMEC	Mouse	[71]	IGF-1 enhances the formation of vessel-like structures and upregulates the expression of angiogenic factors via PI3K/AKT pathway in collagen gel.
HUVEC	Human	[81]	Indirect flow enhances EC sprouting but fails to form vascular networks in fibrin gel, while direct flow inhibits prevascular network formation.
HUVEC	Human	[82]	Pre-culture of ASCs in EGM-2 improves the formation of tube-like structures in a co-culture.
HUVEC	Rat	[83]	Enhanced CD31 expression on co-spun nanofiber substrate.
ECFC	Human	[84]	Co-culture in a hyaluronic acid gel reverses late-passage ASC senescence and shows increased amount of CD31-positive cells.
HDMEC	Human	[85]	Myofibroblast differentiation of ASCs attenuated in co-culture. Hypoxia increases expression of IL-6. Increased expression of VEGF compared with EC culture.