Chitosan biological properties

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... 

Because the biological properties of chitosan are dependent on its physico-chemical properties such as molecular weight (MW) and degree of deacetylation (DD), uniform physico-chemical properties are a prerequisite to specific industrial applications. As an alternative method, fermentation technology for chitosan preparation from fungal cell walls has received much attention as an eco-friendly pathway. Rane and... 

Carreno-Gomez, B., and R. Duncan. 1997. Evaluation of the biological properties of soluble chitosan and chitosan microspheres. Int J Pharm 148 231. 

Verheul RJ, Amidi M et al (2008) Synthesis, characterization and in vitro biological properties of O-methyl free N, N, N-trimethylated chitosan. Biomaterials 29 3642-3649... 

The physical and mechanical properties of chitosan can be amefiorated by using graft copolymerization and crosslinking. Chitosan forms aldimines and ketimines with aldehydes and ketones, respectively. Upon hydrogenation with simple aldehydes, chitosan produces A-alkyl chitosan [60]. The physicochemical and biological properties [61] as well as conformational structures [62] of chitosan are very effective for biomedical applications. 

Another study in this direction was performed by Qiatelet et al. [72]. They investigated the effect of DD on the biological properties of chitosan films by culturing keratinocytes and fibroblasts on chitosan films having different DDs. They found that DD has no significant effect on the in vitro cytocompatibility of chitosan films towards keratinocytes and fibroblasts. They demonstrated that the lower the DD of chitosan, the lower was the cell adhesion on the films, and found that keratinocyte proliferation increases when the DD of chitosan films increases. They concluded from their study that the DD plays a key role in cell adhesion and proliferation, but does not change the cytocompatibility of chitosan. 

Chatelet C, Damour O, Domard A (2001) Infuence of the degree of acetylation on some biological properties of chitosan films. Biomaterials 22 261-268... 

Chang J et al (2008) Biological properties of chitosan films with different degree of deacetylation. J Mater Sci Technol 24(5) 700-708... 

Nwe N, Furuike T, Tamura H (2009) The mechanical and biological properties of chitosan scaffolds for tissue regeneration templates are significantly enhanced by chitosan from... 

Chitosan (CS) nanofibers with a diameter of 150-200 nm were fabricated from a mixed chitosan/ poly (vinyl alcohol) solution by the electrospinning method. Hen egg-white lysozyme was iimno-bilized on electrospun CS nanofibers via cross-hnked enzyme aggregates (CLEAs) and used for effective and continuous antibacterial applications. CS has excellent biological properties, such as biodegradability, biocompatibility, antibacterial properties, non-toxicity, hydrophilicity, high... 

Amidi, M., Romeijn, S. G., Coos Verhoef, f., Junginger, H. E., Bungener, L., Huckriede, A., Crommelin, D. J. A., and Jiskoot, W. (2007). N-Trimethyl chitosan (TMC) nanoparticles loaded with influenza subunit antigen for intranasal vaccination Biological properties and immunogenicity in a mouse model. Vaccine, 25,144-153. 

Table 16.1 Physicochemical and biological properties of chitosan as a function of its molecular weight and degree of deacetylation...

The deacetylation process involves the removal of acetyl groups from chltln molecules. The DAC is defined as the average number of glucosamine units per 100 monomers expressed as a percentage. It determines the content of free amino groups [-NH2] in the chitosan and is one of the most important chemical characteristics that influence the physicochemical properties, biological properties, antibacterial activity, and applications of chitosan. In other words, DAC value determines the functionality, reactivity, polarity, and water solubility of the polymer. Chitin does not dissolve in dilute acetic acid. When chitin is deacetylated to a certain degree ( 60% deacetylation] where it becomes soluble in the acid, it is referred to as chitosan [18, 21]. 

J. liuytm, L. Yubao, X. Chengdong, Preparation and biological properties of a novel composite scaffold of nano-hydroxyapatite/ chitosan/carboxymethyl cellulose for bone tissue engineering, J. Biomed. Sci. 16 (2009) 65. 

The two most important structural parameters that affect the properties of chitosan are the DDA and molecular weight These two factors together determine the physical, chemical, and biological properties of the biopolymer. As for any other polymer, these properties are an average of the contributions of all polymer chains in the sample. 

The DDA of chitosan is an important parameter that determines many physicochemical and biological properties of the biopolymer such as solubility, biodegradability, and biocompatibility. As mentioned earher in this chapter, the DDA of chitosan can be defined as... 

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