Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. It is often converted to its more deacetylated derivative, chitosan. Previously, many reports have indicated the accelerating effects of chitin, chitosan, and its derivatives on wound healing. More recently, chemically modified or nano-fibrous chitin and chitosan have been developed, and their effects on wound healing have been evaluated. In this review, the studies on the wound-healing effects of chitin, chitosan, and its derivatives are summarized. Moreover, the development of adhesive-based chitin and chitosan are also described. The evidence indicates that chitin, chitosan, and its derivatives are beneficial for the wound healing process. More recently, it is also indicate that some nano-based materials from chitin and chitosan are beneficial than chitin and chitosan for wound healing. Clinical applications of nano-based chitin and chitosan are also expected.

Previous reports indicate that N-acetyl-d-glucosamine oligomers (chitin oligosaccharide; NACOS) and d-glucosamine oligomers (chitosan oligosaccharide; COS) have various biological activities, especially against cancer and inflammation. In this review, we have summarized the findings of previous investigations that have focused on anticancer or anti-inflammatory properties of NACOS and COS. Moreover, we have introduced recent evaluation of NACOS and COS as functional foods against cancer and inflammatory disease.

Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. Chitin occurs in nature as ordered macrofibrils. It is the major structural component in the exoskeleton of crab and shrimp shells and the cell wall of fungi and yeast. As chitin is not readily dissolved in common solvents, it is often converted to its more deacetylated derivative, chitosan. Chitin, chitosan, and its derivatives are widely used in tissue engineering, wound healing, and as functional foods. Recently, easy methods for the preparation of chitin and chitosan nanofibers have been developed, and studies on biomedical applications of chitin and chitosan nanofibers are ongoing. Chitin and chitosan nanofibers are considered to have great potential for various biomedical applications, because they have several useful properties such as high specific surface area and high porosity. This review summarizes methods for the preparation of chitin and chitosan nanofibers. Further, biomedical applications of chitin and chitosan nanofibers in (i) tissue engineering, (ii) wound dressing, (iii) cosmetic and skin health, (iv) stem cell technology, (v) anti-cancer treatments and drug delivery, (vi) anti-inflammatory treatments, and (vii) obesity treatment are summarized. Many studies indicate that chitin and chitosan nanofibers are suitable materials for various biomedical applications.