Water absorption in chitosan rapidly increases when the deacetylation degree decreases between 85 and 45%. This seems to contradict the fact that water absorption in chitin is much lower than that of chitosan. The aim of this paper is to understand this feature by measuring the main parameters affecting equilibrium water content. Since swelling capacity depends on the water-polymer interaction, the Flory Huggins interaction parameter was evaluated, finding small or null dependence on the deacetylation degree. Other factor influencing elastic energy is chain stiffness related to the elastic modulus that was measured as a function of deacetylation degree. Besides, crystalline structure was measured by X-ray diffraction patterns as a characteristic of cross-linking density. These observations led us to conclude that the instability of crystals during the swelling process increases with decreasing deacetylation degree, explaining the high equilibrium water content of low deacetylation chitosans.
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http://dx.doi.org/10.1016/j.carbpol.2015.07.020 | DOI Listing |
Langmuir
December 2024
Laboratory of Molecular Chemistry, Materials and Environment (LCM2E), Department of Chemistry, Multidisciplinary Faculty of Nador, University Mohamed I, 60700 Nador, Morocco.
This work involves the synthesis of two chitosan derivatives by reacting chitosan, extracted from shrimp shells in eastern Morocco, with 2-nitrobenzaldehyde via a Schiff base reaction. An amino derivative of chitosan was then produced by reducing the imine group created by sodium borohydride. We investigated the molecular weight (), crystallinity index (), and degree of deacetylation () of the isolated chitosan, among other characteristic features.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Research Center for Complex Physical Systems, Faculty of Sciences, Lucian Blaga University of Sibiu, 550012 Sibiu, Romania.
Chitosan, a natural biopolymer with excellent biocompatibility, biodegradability, and modifiable structure, has broad applications in regenerative medicine, tissue engineering, food packaging, and environmental technology. Its abundance, solubility in acidic solutions, and capacity for chemical modification make it highly adaptable for creating specialized derivatives with enhanced properties. Recent advances have demonstrated chitosan's efficacy in composite systems for tissue regeneration, drug delivery, and antimicrobial applications.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
Laboratorio de Inmunología y Virología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza 66455, NL, Mexico.
The deproteinization of chitosan is a necessary purification process for materials with biomedical purposes; however, chitosan sourcing and purification methods can modify its molecular weight, deacetylation degree, and residual proteins. These factors affect the reactive groups that affect the immunomodulatory activities of cells, particularly macrophages and monocytes; considering this activity is key when developing successful and functional biomaterials. Here, two brands of chitosan were purified and used to synthesize nanoparticles to evaluate their immunomodulatory effect on monocyte and macrophage differentiation.
View Article and Find Full Text PDFCurr Res Microb Sci
November 2024
Department of Biotechnology, Utkal University, Vani Vihar, Bhubaneswar 751004, Odisha, India.
Chitosan is a promising biopolymer with wide range of applications. It is the deacetylated product of chitin. Commercially, it is produced from chitin via a harsh thermochemical process that has several shortcomings and heterogenous deacetylation product.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang Engineering Laboratory of Food Technology and Equipment, Zhejiang University, Hangzhou 310058, China; College of Agriculture & Biotechnology, Zhejiang University, Hangzhou 310058, China; Zhejiang University Zhongyuan Institute, Zhengzhou 450000, China; Shandong (Linyi) Institute of Modern Agriculture, Zhejiang University, Linli 276000, China; Ningbo Research Institute, Zhejiang University, Hangzhou 315100, China; Innovation Center of Yangtze River Delta, Zhejiang University, Jiaxing 314102, China.
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