Synthesis, properties, and applications of chitosan hydrogels as anti-inflammatory drug delivery system

As a chitin- and glucosamine-derived polysaccharide, chitosan is biodegradable, biocompatible, and non-toxic. Among the latest high-value engineering materials, chitosan hydrogels own outstanding features such as biodegradability, biocompatibility, non-toxicity, swelling reversibility, flexible adaption to external triggers, and the capability of drug loading. Recently, applying chitosan hydrogels to facilitate human biological processes like inflammation has become an interesting topic demonstrated by many publications about their potential in wound dressing, tissue engineering, and treatment of cancer, Parkinson's disease, and gastric ulcer. This paper reviews the most recent procedures for synthesizing chitosan hydrogels as a smart anti-inflammatory drug delivery system. The characteristics of chitosan hydrogel, including pH sensitivity, temperature sensitivity, electric sensitivity, and magnetic strength, for flexible anti-inflammation, are all discussed to provide a comprehensive overview of anti-inflammatory chitosan hydrogel.