Table 1.

Summary of major applications of chitin and chitosan in the different fields.

Field of Application	Applications	References
Biomedical and Pharmaceutical applications	Antioxidant: free radical scavenger/quencher Antimicrobial agent: positively charged chitosan-NH2 groups interact with negatively charged microbial cell membrane creating pores Drug delivery: mucoadhesive properties increase drug permeation of intestinal, nasal, and buccal epithelial cells, Gene therapy: Delivering various genes and siRNA Chitosan based drugs. For example, lowering effect of cholesterol for obesity treatment Regenerative technology/tissue engineering: bone, neural, cornea, cardiac and skin regenerative technology. Provides a three-dimensional tissue growth matrix, activate macrophage activity and stimulate cell proliferation Wound management: homeostatic agent, participate in repair, replacement, activation of humor immunity, complement system, and CD4+ cells, enhances granulation as well as the organization of the repaired tissues. It slowly degrades into N-acetyl-β-d-glucosamine that stimulates fibroblast proliferation, regular collagen deposition in addition to stimulating hyaluronic acid synthesis at the wound site.	[11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33]
Health care products	Cosmetics formulations: Antimicrobial, antifungal, UV absorbing abilities exploited in various cosmetics formulations including in shampoos, rinses, colorants, hair lotions, spray, toothpaste formulations and tonics. Sunscreens, moisturizer foundation, eyeshadow, lipstick, cleansing materials, and bath agent, toothpaste, mouthwashes, and chewing gum as a dental filler.	[34,35,36,37]
Food Industry	Packaging, edible coatings, body filling, emulsifying agent, natural flavor extender, texture controlling, thickening and stabilizing agent, food preservation (antimicrobial agent), antioxidant agent. Flocculation/Clarification and deacilification of fruits and beverages	[38,39,40,41,42,43,44,45]
Agriculture	Antimicrobial activities against various plant pathogens. Fruit preservative. controlled delivery of fertilizers, pesticides, and insecticides. Increase in the auxin concentration and urea release in the soil, germination capacity, root length and activity, and seedling height	[46,47,48]
Industrial application	Functional materials: Graphitic carbon nanocapsules/composites, tungsten carbide chitin whiskers, etc. are used in the production of micro-electrochemical systems and 3D networks	[49,50,51]
	Electrolyte: Sulfuric acid and chitosan combination has the ability to discharge high voltage Chitosan provides ionic conductivity and can be used in the production of solid-state batteries Photography: fixing agent for color prints	[52,53,54,55,56,57,58,59]
	Paper manufacture: Production of filter papers, water-resistant papers, biodegrading packages, water-resistant papers	[59,60,61,62,63]
	Enzyme carrier: immobilizing enzymes on solid materials	[64,65,66]
Construction industry	wood adhesive, fungicide, wood quality enhancer, and preservative	[67,68,69]
Waste treatment	Flocculating, and negative charge (chelating agent), for dye, heavy metal ions removal and decontamination. Used for various processing plants such as whey, dairy, poultry, and seafood processing plants	[70,71,72,73,74,75]