“…Based on the ability to gel with metal ions, different alginate-based materials with various morphology were developed, such as the porous scaffold [ 9 , 10 , 11 ], hydrogel [ 12 , 13 ], fiber [ 14 , 15 , 16 ], nonwoven fabric [ 17 , 18 ], membrane [ 19 , 20 , 21 ], and so forth. The common way to fabricate the alginate-based materials includes ion cross-linking [ 22 ], microfluidic spinning technique [ 23 ], freeze-drying [ 24 ], wet spinning technology [ 25 ] and immersive rotary/centrifugal jet spinning technique [ 26 , 27 , 28 ]. Recently, alginate hydrogel has been prepared by the freeze-drying technique or ionic cross-linking method.…”