Chitin is the second most abundant biopolymer after cellulose. It is harvested from different biological sources such as crustaceans, fungi, insects and molluscs. Chitosan is derived from chitin following deacetylation and is composed of (1-4)-linked 2-amino-2-deoxy-β-D-glucose monomers with 50 or more mole % free amino groups.1 Chitosan is usually obtained from chitin through alkaline hydrolysis of chitin under reflux conditions. Chitosan is multifunctional (primary –OH, secondary –OH and –NH2) and is the only cationic biopolymer available from the natural sources. The properties of chitosan such as anti-microbial, anti-fungal, haemostatic nature, biocompatibility as well as biodegradability along with easy of availability has enabled its use in a number of fields that include medical, pharmaceutical, water treatment, agriculture, tissue engineering and so on.2
Chitosan is soluble in acidic medium and therefore this enables its processing. In the literature, different techniques are available for the processing of chitosan. The processing of chitosan can lead to different forms such as sponge, hydrogel, film, membranes, nanofiber, nanoparticles etc.3 The porous form of chitosan finds a number of applications such as water treatment, adsorption of dye, adsorption of metal ions, drug delivery, gene therapy, scaffold for cell growth, and in agriculture as water and micronutrient reservoir. The films formed by chitosan have been largely used as food packaging materials but the limitation of chitosan films is not limited to the packaging; they are also used for sensors, wound dressing and so on. The products and applications of chitosan are vast and therefore this seminar aims to address preparation and properties of chitosan in the porous and film forms.
References
(1) Azmana, M.; Mahmood, S.; Hilles, A. R.; Rahman, A.; Arifin, M. A. Bin; Ahmed, S. A Review on Chitosan and Chitosan-Based Bionanocomposites: Promising Material for Combatting Global Issues and Its Applications. Int. J. Biol. Macromol. 2021, 185, 832–848. https://doi.org/10.1016/j.ijbiomac.2021.07.023.
(2) Dragan, E. S.; Dinu, M. V. Advances in Porous Chitosan-Based Composite Hydrogels: Synthesis and Applications. React. Funct. Polym. 2020, 146, 104372. https://doi.org/10.1016/j.reactfunctpolym.2019.104372.
(3) Muxika, A.; Etxabide, A.; Uranga, J.; Guerrero, P.; de la Caba, K. Chitosan as a Bioactive Polymer: Processing, Properties and Applications. Int. J. Biol. Macromol. 2017, 105, 1358–1368. https://doi.org/10.1016/j.ijbiomac.2017.07.087.