Hydrogels, which possess three-dimensional network structure and full of water, have been the hotspot in biomedical field. Because their liquidity, size, elasticity and stiffness properties are readily regulated and designed, they could extremely mimic the extracellular matrix and living tissue. Compared to traditional preformed hydrogel, injectable hydrogel is a kind of novel material which could avoid large surgical incisions and much more adaptable to match the complicated situation and shape in vivo. Fu...