Table 3.

Different cells in hydrogel.

Cells	Functions	Mechanism	Methodology	Merits	Reference
HUVECs	Vascularization	Prevent the need for pre-formed channels or growth factor-induced angiogenesis.	HUVECs was seeded in the Laponite (LAP) nanoclay with VEGF.	Low cost, ease of isolation, and strong angiogenic potential	[110]
MSCs	Vascularization	Increase the expression of vascular growth factors.	A 3D-printed GelMA hydrogel scaffold with a controlled internal structure which was filled with MSCs.	Immunomodulatory and tissue repair promoting effects Potential for multi-directional tissue differentiation The ability to secrete a variety of cytokines	[118]
	Immunomodulation	Promote paracrine activity during inflammation and induce a shift from an M1-type phenotype to an M2-type phenotype in macrophages.	A scaffold which was composed by the aloe vera–sodium alginate (AV-ALG) hydrogel-coated endometrial mesenchymal stem cells (eMSCs) and 3D melt electrospun wire nets.		[122]
	Regulation of collagen deposition	Inhibition of inflammation in scar tissue. Affect fibroblast activity in scar formation, and reduce scar formation by inhibiting the gene expression of TGF-β1 and decreasing type I collagen production. Play a positive role in collagen remodeling in scar tissue.