Abstract
The review introduce hydrogel, responsive hydrogel briefly, then describe the characteristics of chitin, chitosan, and chitinous materials. Different chitinous physical hydrogels, chemical hydrogels, polyelectrolytes complex, semi-interpenetrating polymer networks, blends and complex are introduced. Why prepared different shapes of hydrogel are also introduced. The applications of chitinous hydrogels in areas of biosensor, biocarrier, controlled release systems, absorption of heavy metal/ harmful materials, immobilized enzyme, medical device, tissue engineering, wound dressing and the others are listed. Recently developments in tissue engineering, microfabrication, hydrogel nanoparticles are stressed.
