ABSTRACT
Hydrophilic gels or hydrogels derive their ability to absorb water from hydrophilic functional groups attached to their polymeric backbone, while their resistance to dissolution arises from crosslinks between network chains. This chapter highlights recent developments, synthesis, characterization, and application of hydrogels with biological responsiveness built-in. Natural hydrogels are generally prepared using polysaccharides such as hyaluronic acid, chitosan, alginate, cellulose, starch or protein, including collagen, fibrin. Collagen-based hydrogels have been developed and widely used due to its ubiquitous presence in different tissues of body. Natural polysaccharides based hydrogels are of great interest for biomaterials scientists because they provide intrinsic bioactivities such as cell adhesion, biodegradability. Synthetic hydrogels are more reproducible, easily synthesized in large quantities with controlled parameters such as molecular weight, molecular architectures, and microscopic morphologies.
