Table 2.

Crosslinking methods and time of hydrogels commonly used for skin bioprinting.

Hydrogels	Crosslinking Method	Crosslinking Time	References
Collagen	hydrophobic bonding	0.5–60 min	[87,95,96,97]
Gelatin	temperature/glutaraldehyde	minutes to hours	[29,34,98]
Alginate	CaCl2	seconds	[36,87,99,100]
Fibrin	thrombin	seconds	[101,102,103,104]
Hyaluronic acid	thiol group crosslink/UV light	15–30 min/s	[35,65,87,105,106]
Chitosan	pH	5–50 min	[87,92,107,108,109]
Pectin	thiol group crosslink	15–30 min	[110,111,112,113,114,116]