Hydrogel is a three-dimensional network material composed of macromolecule polymers. It has advantages of biocompatibility
high environmental sensitivity
biodegradability and no pollution to the environment by using natural polymers and their derivatives. The application of natural polymer hydrogel in medicine
food
agriculture and environmental protection in recent years is reviewed in this paper. According to the different sources of materials
the classification of protein and polypeptide hydrogels
alga polysaccharide hydrogels
animal polysaccharide hydrogels
plant polysaccharide hydrogels
their modification
and the latest technology
functional properties and application fields of composite hydrogels were reviewed. Finally
the improvement direction and key application fields of natural polymer hydrogels in the future are prospected.