Chitosan: A Natural Biopolymer with a Wide and Varied Range of Applications

Abstract

Although chitin is of the most available biopolymers on Earth its uses and applications are limited due to its low solubility. The deacetylation of chitin leads to chitosan. This biopolymer, composed of randomly distributed β-(1-4)-linked D-units, has better physicochemical properties due to the facts that it is possible to dissolve this biopolymer under acidic conditions, it can adopt several conformations or structures and it can be functionalized with a wide range of functional groups to modulate its superficial composition to a specific application. Chitosan is considered a highly biocompatible biopolymer due to its biodegradability, bioadhesivity and bioactivity in such a way this biopolymer displays a wide range of applications. Thus, chitosan is a promising biopolymer for numerous applications in the biomedical field (skin, bone, tissue engineering, artificial kidneys, nerves, livers, wound healing). This biopolymer is also employed to trap both organic compounds and dyes or for the selective separation of binary mixtures. In addition, chitosan can also be used as catalyst or can be used as starting molecule to obtain high added value products. Considering these premises, this review is focused on the structure and modification of chitosan as well as its uses and applications.

Polylactic Acid (PLA) Biocomposite: Processing, Additive Manufacturing and Advanced Applications

“…PLA is a naturally resourced thermoplastic polymer produced globally with a capacity of approximately 211,000 tons in 2020 [91]. In addition, chitosan and chitin derivatives productions were about 107,000 tons [92], while cellulose and PHA were produced globally with a capacity of over 580,000 tons and 30,000 tons, respectively, in 2020 [93]. These data had been represented as graph bar in Figure 5.…”

Evaluation of Antinociceptive Effects of Chitosan-Coated Liposomes Entrapping the Selective Kappa Opioid Receptor Agonist U50,488 in Mice

“…Due to its low toxicity, biodegradability and biocompatibility, chitosan has been increasingly studied in a wide range of pharmaceutical, biomedical, and biotechnological fields, including gene therapy, bone regeneration, food industry, and agriculture [ 45 , 46 ]. Chitosan displays hemostatic and hastening wound healing effects, anti-hypercholesterolemic effects, bioactivity, chemotactic actions, antimicrobial activity, immunostimulation, enzymatic biodegradability, mucoadhesion, andepithelial permeability [ 47 , 48 , 49 , 50 ].…”

Recent Developments in Chitosan-Based Adsorbents for the Removal of Pollutants from Aqueous Environments

“…The soluble-insoluble transition occurs at about a pH of 6.5 (p K a of the amino group). This characteristic makes chitosan a cationic polyelectrolyte (p K a ≈ 6.5), one of the few found in nature [ 19 , 27 ].…”

“…It is known that chitosan powders or flakes are non-porous materials which present a low surface area (lower than 10 m 2 g −1 ) [ 23 ]. Thus, chemical and physical modifications of chitosan have been performed to increase the surface area and improve potential applications [ 17 , 27 , 58 , 59 , 116 , 117 ]. Phongying et al [ 118 ] obtained chitosan directly from chitin and prepared chitosan nanoscaffolds in order to improve the surface area, particle size and pore volume.…”

“…In this review, the applications of chitosan-based materials as adsorbents for the removal of pollutants from aqueous environments are reviewed. Although there are a number of review articles that describe the environmental applications of chitosan [ 19 , 24 , 26 , 27 ], in this review we focus initially on the sources, properties and chemical modifications of chitosan and discuss the various factors that influence its properties as a material for the removal of pollutants. Next, we review the support materials utilised and combined with chitosan, including the emerging carbon and silicon supports, providing a more comprehensive account than previously published.…”