Biocompatibility chitin/Chitosan

Chitin, a )5(l- 4)-linked iV-acetyl-D-glucosamine (GlcNAc) polysaccharide, is well-known for the excellent characters such as biodegradability and biocompatibility 36), Chitosan is a )ff(l- 4)-linked D-glucosamine (GlcN) polysaccharide, which is iV-deacetylated polysaccharide of chitin 41). Chitosan... 

Chung L et al (1994) Biocompatibility of potential wound management products fungal mycelia as a source of chitin/chitosan and their effect on the proliferation of human ElOOO fibroblasts in culture. J Biomed Mater Res 28 463-469... 

Chitosan is a nontoxic and biocompatible linear polysaccharide derivate from chitin. Chitin is found in the exoskeleton of crustaceans, in fungal cell wall, and in some biomaterials. The partial deacetylation of chitin, in the presence of hot alkali, leads to the formation of chitosan. Chitosan (Figure 31.8) is formed by 80% p-(l,4)-2-amino-2-deoxy D-glucose and 20% p-(l,4)-2-acet-amido-2-deoxy-D-glucose repeating units. Unlike insoluble chitin, chitosan is soluble in acid solution, conditions that lead to the protonation of amino groups that are responsible for its polyelectrolyte character. Both deacetylation degree (DD) and molar mass have been shown to influence properties of chitosan in solution. " ... 

In contrast, the positive charge of chitosan induced by deacetylation of chitin, a natural polysaccharide found in crab shells and many shellfish, is supposed to be correlated with cell attachment increase, inflammation reduction, and biocompatibility enhancement. Chitosan will not trigger an immune response and promote cell adhesion and spreading such as osteoblasts [38], keratinocytes, and neuronal cells. It can also be covalently bonded to adhesion peptides such as the RGD to improve cell adhesion [39]. 

Kamble et al (2007) reported on the applicability of chitin, chitosan and chemically modified chitosan (20%-lanthanum chitosan) as adsorbents for the removal of excess F from drinking water. Chitosan which is derived from chitin is one of the main components of crustacean shells of prawn, crab, shrimp or lobster, has the ability to coordinate metal ions because of its high concentration of amine functional groups (Li et al, 1992). It is also a non-toxic, biodegradable and biocompatible material. Furthermore, the effects of various physico-chemical parameters such as pH, adsorbent dose, initial F concentration and the presence of interfering ions on adsorption of F were assessed by Kamble et al (2007). The authors concluded that lanthanum chitosan adsorbents were better at removal of F from water than plain chitosan and chitin (Fig. 6.2). 

Biopolymer-based SAPs have their advantages in their biocompatibility and non-toxicity. Various specific applications, such as alternative diuretic therapy (J), controlled drug delivery ( ), cultivation of the cell (5), hypocaloric dietary treatment (6) have been proposed for decades. Potential natural polymers are cellulose or starch, chitin-chitosan, alginate, hyaluronic acid, etc. 

Another polysaccharide system that has received considerable interest is the chitosans which are water soluble derivatives of chitin. These materials appear to be very biocompatible and degradable and so are potentially excellent candidates as polymeric drug systems (27). 

Chitosan, the most abundant marine mucopolysaccharide, is derived from chitin by alkaline deacetylation, and possesses versatile biological properties such as biocompatibility, biodegradability, and a non-toxic nature. Due to these characteristics, considerable attention has been given to its industrial applications in the food, pharmaceutical, agricultural, and environmental industries. Currently, chitosan can be considered as a potential marine nutraceutical because its remarkable biological activities have been investigated and reported, in order to exploit its nutraceutical... 

Chitin is known to be biodegradable, biocompatible, and nontoxic. It is used in dmg delivery and bio medical applications. It also used in the purification of water especially for the absorption of toxic dyes. Chitin has limited solubility in solvents but chitosan is readily soluble in acidic aqueous solutions and has more tendency to be chemically modified. Chitosan can readily be spun into fibers, cast into films, or precipitated in a variety of micromorphologies from acidic solutions. Min and Kim have reported on the adsorption of acid dyes from wastewater using composites of PAN/chitosan [52]. Shin et al. has reported on copolymers composed of PVA and poly dimethyl siloxanes cross-linked with chitosan to prepare semi IPN hydrogels for application as biomedical materials... 

---