TABLE 2.

The methods of synthesizing hydrogel scaffolds.

Technology	Operational approach	Advantages	Ref.
Injectable technology	Bulk mixing	Easy to operate Minimally invasive Complete filling of the defect site	(Chen et al., 2022)
3D bioprinting technology	3D bioprinter printing	Precise control of cell distribution and growth in scaffold	(Chen et al., 2021)
Microfl uidic technology	Microfluidic mixing	Small reaction solution volume and high production efficiency Controllable reaction and the size of the product can be controlled by adjusting the flow rate and pressure Simple reaction process Low cost Reduce tedious post purification processes	(Karnik et al., 2008)