ABSTRACT
Biopolymers have received attention as tissue engineering (TE) substrates, with several studies examining materials such as alginate, chitosan, and gelatin as cell scaffolds for both two-dimensional (2D) and three-dimensional (3D) cell culture (Pan et al. 2005, Park et al. 2005). In recent years, carbohydrate polymers have been extensively used in biomedical and pharmaceutical applications because of their biocompatibility and biodegradability (Tabata and Ikada 1998). Polysaccharides represent one of the most abundant industrial raw materials and have been the subject of intensive research owing to their sustainability, biodegradability, and biosafety. Currently, the uses of chitin and chitosan have been postulated in numerous areas of biopharmaceutical research, such as mucoadhesion, permeation enhancement, vaccine technology, gene therapy, and wound healing. Chitin is a known biodegradable natural polymer based on polysaccharides, which is obtained from crustacean shell (e.g., crab, shrimp, and lobster), some insects (e.g., true y and sulfur buttery), and fungi such as yeasts and plants. It principally occurs in animals of the phylum Arthopoda (Zheng et al. 2001). Historically, in 1811, Professor Henri Braconnot, isolated brous substances from mushroom and found them to be insoluble in aqueous acidic solution. A decade later in 1823, Ojer named it “chitin” from Greek “khiton” meaning “envelope” present in certain insects. In 1894, Hope Seyle named it as “chitosan.” From 1930 to 1940, this biopolymer of glucosamine gained much interest in the eld of medicine. Chitosan obtained from partial deacetylation of chitin is a polysaccharide comprising copolymers of glucosamine and N-acetylglucosamine. Chitosan is commercially available in several types and grades that vary in molecular weight between 10,000 and 1,000,000 and vary in degree of deacetylation and viscosity. Technically speaking, Chitosan is a naturally occurring substance that is chemically similar to cellulose, which is a plant ber. Like plant bers, chitosan possesses many of the same properties as ber; however, unlike plant ber, it has the ability to signicantly bind fat, acting like a “fat sponge” in the digestive tract. It attracts the biohazardous substances, such as greases, oils, heavy metals, and other potentially toxic substances from the water and it is used for detoxifying water (Miyazaki et al. 1981).
