Special Issue "Chitin and Chitosan: Properties and Applications"

A special issue of Polymers (ISSN 2073-4360).

Deadline for manuscript submissions: 30 September 2019

Special Issue Editor

Guest Editor
Prof. Dr. San-Lang Wang

Department of Chemistry/Life Science Development Center, Tamkang University, Taiwan
Website | E-Mail
Phone: 886-2-26215656 ext. 3038
Interests: marine chitin; applied microbiology; enzyme inhibitors; antidiabetic drugs

Special Issue Information

Dear Colleagues,

This Special Issue is dedicated to chitin and chitosan: properties and applications. The development of new polymer materials has recently become an extremely fascinating research topic, especially in relation to chitin and chitosan. Chitin, chitosan, and their derivatives hold great economic merit due to their versatile activities and biotechnological applications. Chitin and chitosan are traditionally prepared from chitin-containing fishery processing (shrimp shells, crab shells, and squid pens) through various procedures including chemical, enzymatic, and microbial treatments. For improving their properties, chemical modifications have also been intensively studied. Compared to synthetic polymers, chitin and their derivatives have advantages of being biocompatible, biodegradable and sustainable.

The aim of this Special Issue is to discuss their manufacturing, modification, characterization, as well as their various physical and chemical applications in biomedical and green industry fields. Both research and review articles are welcome.

Prof. San-Lang Wang
Guest Editor

Manuscript Submission Information

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Chitin/chitosan
  • Chitin/chitosan modification
  • Chitin/chitosan film, chitin/chitosan fiber, chitin/chitosan gel
  • Chitin/chitosan oligomer
  • Chitinase/chitosanase
  • Biomacromolecules and functional materials
  • Chitin/chitosan polymer design and characterization
  • Chitin/chitosan physical and chemical properties

Published Papers (8 papers)

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Research

Open AccessArticle
The Use of Lanthanum Ions and Chitosan for Boron Elimination from Aqueous Solutions
Polymers 2019, 11(4), 718; https://doi.org/10.3390/polym11040718
Received: 14 March 2019 / Revised: 7 April 2019 / Accepted: 14 April 2019 / Published: 19 April 2019
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Abstract
Boron is an essential element for plants and living organisms; however, it can be harmful if its concentration in the environment is too high. In this paper, lanthanum(III) ions were introduced to the structure of chitosan via an encapsulation technique and the obtained [...] Read more.
Boron is an essential element for plants and living organisms; however, it can be harmful if its concentration in the environment is too high. In this paper, lanthanum(III) ions were introduced to the structure of chitosan via an encapsulation technique and the obtained hydrogel (La-CTS) was used for the elimination of the excess of B(III) from modelling solutions. The reaction between boric acid and hydroxyl groups bound to the lanthanum coordinated by chitosan active centres was the preponderant mechanism of the bio-adsorption removal process. The results demonstrated that La-CTS removed boric acid from the aqueous solution more efficiently than either lanthanum hydroxide or native chitosan hydrogel, respectively. When the initial boron concentration was 100 mg/dm3, the maximum adsorption capacity of 11.1 ± 0.3 mg/g was achieved at pH 5 and the adsorption time of 24 h. The successful introduction of La(III) ions to the chitosan backbone was confirmed by Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy, Fourier-Transform Infrared Spectroscopy, X-Ray Diffraction, X-ray Photoelectron Spectroscopy, and Inductively Coupled Plasma Optical Emission Spectroscopy. Due to its high-performance boron adsorption-desorption cycle and convenient form, La-CTS seems to be a promising bio-adsorbent for water treatment. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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Open AccessArticle
The Modulation of Chitosan-DNA Interaction by Concentration and pH in Solution
Polymers 2019, 11(4), 646; https://doi.org/10.3390/polym11040646
Received: 7 February 2019 / Revised: 3 April 2019 / Accepted: 8 April 2019 / Published: 9 April 2019
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Abstract
Chitosan has been widely used to prepare a DNA carrier for highly efficient and non-toxic gene therapy. In the present study, we investigated DNA charge neutralization and compaction by chitosan in solutions of various pH levels by dynamic light scattering (DLS), magnetic tweezers [...] Read more.
Chitosan has been widely used to prepare a DNA carrier for highly efficient and non-toxic gene therapy. In the present study, we investigated DNA charge neutralization and compaction by chitosan in solutions of various pH levels by dynamic light scattering (DLS), magnetic tweezers (MT), and atomic force microscopy (AFM). We found that when chitosan concentration is higher than a critical value (0.2 µM), corresponding the ratio of phosphate and NH2 in chitosan k = 1.9 , the electrophoretic mobility of DNA-chitosan complex maintains an almost constant value when pH of solution is less 6.5, the isoelectric point of chitosan. Then it decreases with increasing pH of solution. However, when chitosan concentration is lower than the critical value, the mobility of the complex increases with pH in the range of acidity and reaches the maximum when the pH of the solution approaches the isoelectric point of chitosan. It finally decreases with increasing pH in solutions. The corresponding condensing force of the DNA-chitosan complex measured by single molecular MT changes accordingly with its charge neutralization in the same solution concentration (20 µM) and is consistent with the DLS measurements. This phenomenon might be related to the weakening interaction between DNA and chitosan in low pH solutions, and is verified by measuring the ratio of free chitosan to DNA complex in solutions. We also observed the various morphologies of DNA-chitosan complexes, such as ring, rod, flower, braid, and other structures, under different degrees of deacetylation, molecular weight, solution concentration and pH in solutions by AFM. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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Open AccessArticle
Synthesis of Self-Healing Waterborne Polyurethane Systems Chain Extended with Chitosan
Polymers 2019, 11(3), 503; https://doi.org/10.3390/polym11030503
Received: 30 January 2019 / Revised: 9 March 2019 / Accepted: 12 March 2019 / Published: 15 March 2019
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Abstract
In this study, the self-healing properties of waterborne polyurethane (WPU) were implemented by chitosan as a chain extender of polyurethane prepolymers. The physical properties and self-healing efficiency of WPU were studied by changing the molar fractions of chitosan from 0.1 to 0.3. After [...] Read more.
In this study, the self-healing properties of waterborne polyurethane (WPU) were implemented by chitosan as a chain extender of polyurethane prepolymers. The physical properties and self-healing efficiency of WPU were studied by changing the molar fractions of chitosan from 0.1 to 0.3. After thermal treatment for 24 h at 110 °C, the self-healing efficiency for the tensile strength of the highest chitosan content (WPU-C3) was found to be 47%. The surface scratch was also completely restored. The efficiency of the sample with the lowest chitosan content (WPU-C1) was found to be 35%, while that of the control sample without chitosan (WPU-C0) was 4%. The self-healing properties of the as-prepared films were attributed to the exchange reactions between the hydroxyl groups of chitosan and the urethane groups in the films at elevated temperature. It is inferred that self-healing WPU can be synthesized by chain extension with chitosan. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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Open AccessArticle
Chitosan Grafted Adsorbents for Diclofenac Pharmaceutical Compound Removal from Single-Component Aqueous Solutions and Mixtures
Polymers 2019, 11(3), 497; https://doi.org/10.3390/polym11030497
Received: 7 February 2019 / Revised: 9 March 2019 / Accepted: 11 March 2019 / Published: 14 March 2019
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Abstract
The main purpose of this study was to investigate the synthesis of some cross-linked carboxyl-grafted chitosan derivatives to be used as selective adsorbents for diclofenac (DCF) pharmaceutical compounds from aqueous mixtures. Four different materials were synthesized using succinic anhydride (CsSUC), maleic anhydride (CsMAL), [...] Read more.
The main purpose of this study was to investigate the synthesis of some cross-linked carboxyl-grafted chitosan derivatives to be used as selective adsorbents for diclofenac (DCF) pharmaceutical compounds from aqueous mixtures. Four different materials were synthesized using succinic anhydride (CsSUC), maleic anhydride (CsMAL), itaconic acid (CsITA), and trans-aconitic acid (CsTACON) as grafting agents. After synthesis, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were performed before and after DCF adsorption. In addition, a complete adsorption evaluation was carried out for all materials studying some important parameters. The optimum pH was 4; the amino groups of DCF can be protonated at pH = 4 (–NH+), so this groups can easily attract the clear negatively carboxyl moieties (–COO) of the chitosan adsorbents. The Qm for CsTACON was higher than those of the other materials, at all temperatures studied. By altering the temperature from 25 to 35 °C, an increase (16%) of Qm (from 84.56 to 98.34 mg g−1) was noted, while similar behavior was revealed after a further increase of temperature from 35 to 45 °C, improving by 5% (from 98.34 to 102.75 mg g−1). All isotherms were fitted to Langmuir, Freundlich, and Langmuir-Freundlich (L-F) models). In addition, a kinetic model was proposed taking into account not only the interactions but also the diffusivity of the molecule (DCF) into the polymeric network. The behavior of the prepared chitosan materials in simultaneously removing other compounds (synergetic or antagonistic) was also evaluated by experiments performed in mixtures. DCF presented the highest removal from the mixture in the order: CsTACON (92.8%) > CsITA (89.5%) > CsSUC (80.9%) > CsMAL (66.2%) compared to other pharmaceutical compounds (salicylic acid, ibuprofen and ketoprofen). Desorption was achieved by using different eluants (either water or organic). The highest desorption ability was found for acetone (100% for CsTACON, CsSUC, CsMAL and 77% for CsITA) for all materials. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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Open AccessArticle
Synthesis, Characterization, and Sludge Dewaterability Evaluation of the Chitosan-Based Flocculant CCPAD
Polymers 2019, 11(1), 95; https://doi.org/10.3390/polym11010095
Received: 9 December 2018 / Revised: 27 December 2018 / Accepted: 30 December 2018 / Published: 8 January 2019
Cited by 2 | PDF Full-text (3716 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Carboxymethyl chitosan (CMCS), acrylamide, and methacryloxyethyltrimethyl ammonium chloride were used as co-monomers to produce a sludge dewatering agent carboxymethyl chitosan-graft-poly(acrylamide-methacryloxyethyltrimethyl ammonium chloride) (CCPAD) by UV-induced graft polymerization. Single-factor experiments and response surface methodology were employed to investigate and optimize the grafting rate, grafting [...] Read more.
Carboxymethyl chitosan (CMCS), acrylamide, and methacryloxyethyltrimethyl ammonium chloride were used as co-monomers to produce a sludge dewatering agent carboxymethyl chitosan-graft-poly(acrylamide-methacryloxyethyltrimethyl ammonium chloride) (CCPAD) by UV-induced graft polymerization. Single-factor experiments and response surface methodology were employed to investigate and optimize the grafting rate, grafting efficiency, and intrinsic viscosity influenced by the total monomer concentration, CMCS concentration, cationic degree, pH value, and illumination time. The structure, surface morphology, and thermal stability of CCPAD were characterized by infrared spectroscopy, hydrogen nuclear magnetic resonance, X-ray diffraction, scanning electron microscopy, and differential thermal-thermogravimetry. The raw sludge with 97.9% water content was sourced from the concentrated tank of a sewage treatment plant and used in the sludge condition experiments. In addition, CCPAD was applied as the sludge conditioner to investigate the effects of cationic degree, intrinsic viscosity, and pH on the supernatant turbidity, moisture content, specific resistance to filtration, and sludge settling ratio. Moreover, the mechanism of sludge conditioning by CCPAD was discussed by examining the zeta potential and extracellular polymeric substance (EPS) content of the supernatant. The sludge dewatering results confirmed that CCPAD had excellent performance for improving sludge dewaterability. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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Open AccessArticle
The Drop-in-Drop Encapsulation in Chitosan and Sodium Alginate as a Method of Prolonging the Quality of Linseed Oil
Polymers 2018, 10(12), 1355; https://doi.org/10.3390/polym10121355
Received: 6 November 2018 / Revised: 3 December 2018 / Accepted: 4 December 2018 / Published: 6 December 2018
Cited by 1 | PDF Full-text (795 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Nowadays, the encapsulation of sensitive products by various techniques has become popular as a promising preservation method. In particular, this applies to oils with a high content of unsaturated fatty acids and a high susceptibility to deterioration. This work presents the possibility of [...] Read more.
Nowadays, the encapsulation of sensitive products by various techniques has become popular as a promising preservation method. In particular, this applies to oils with a high content of unsaturated fatty acids and a high susceptibility to deterioration. This work presents the possibility of using a chitosan and sodium alginate in the form of a hydrogel membrane to protect food ingredients such as linseed oil, which is stored in an aquatic environment. The obtained results showed the high efficiency of the coaxial method encapsulation, which did not affect the quality of the oil measured after encapsulation. The greatest protective effect was observed in the linseed oil–chitosan membrane system, in which the primary and secondary oxidation products content were 88% and 32% lower than in the control sample, respectively. The smallest changes of the fatty acid profile, conjugated dienes, and trienes were observed in the chitosan capsules with linseed oil compared to the control sample. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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Open AccessArticle
Isothermal Adsorption Properties for the Adsorption and Removal of Reactive Blue 221 Dye from Aqueous Solutions by Cross-Linked β-Chitosan Glycan as Acid-Resistant Adsorbent
Polymers 2018, 10(12), 1328; https://doi.org/10.3390/polym10121328
Received: 26 October 2018 / Revised: 26 November 2018 / Accepted: 28 November 2018 / Published: 30 November 2018
Cited by 3 | PDF Full-text (4768 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Dye effluent causes serious pollution and damage to the environment and needs a series of treatments before it can be discharged. Among the numerous effluent treatment methods, adsorption is the simplest and does not cause secondary pollution. Bio-adsorbents are especially advantageous in the [...] Read more.
Dye effluent causes serious pollution and damage to the environment and needs a series of treatments before it can be discharged. Among the numerous effluent treatment methods, adsorption is the simplest and does not cause secondary pollution. Bio-adsorbents are especially advantageous in the treatment of low-concentration dye effluent. In this study, the adsorption and removal capacities of unmodified α- and β-chitosan and modified β-chitosan (β-chitosan cross-linked with triethylenetetramine, BCCT) on C.I. Reactive Blue 221 (RB221) dye were compared. The experiments were performed on the adsorption of the RB221 dye by unmodified α- and β-chitosan and cross-linkage–modified BCCT at different temperatures and for different durations, which are presented along with the relevant adsorption kinetics calculations. According to the results, as the temperature increased from 303 to 333 K, the initial adsorption rates of the adsorbents, α-chitosan, β-chitosan, and BCCT, for the RB221 dye, changed from 1.01 × 102, 4.74 × 102, and 1.48 × 106 mg/g min to 5.98 × 104, 4.23 × 108, and 1.52 × 1013 mg/g min, respectively. BCCT thus showed the best adsorption for the dye at all temperatures from the Elovich model. These results confirmed the successful introduction of a polyaminated and cross-linked extended structure as a modification for the BCCT adsorbent, which makes it resistant to acid hydrolysis and gives it the functional amine group for dye adsorption, thereby promoting the ability of BCCT to adsorb dyes under strongly acidic conditions. The compound synthesized in this study is expected to be a good choice in the future for purifying strongly acidic effluent containing anionic organic dyes. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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Open AccessArticle
Injectable and Gellable Chitosan Formulations Filled with Cellulose Nanofibers for Intervertebral Disc Tissue Engineering
Polymers 2018, 10(11), 1202; https://doi.org/10.3390/polym10111202
Received: 5 September 2018 / Revised: 21 October 2018 / Accepted: 22 October 2018 / Published: 27 October 2018
Cited by 3 | PDF Full-text (5798 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The development of non-cellularized injectable suspensions of viscous chitosan (CHI) solutions (1.7–3.3% (w/w)), filled with cellulose nanofibers (CNF) (0.02–0.6% (w/w)) of the type nanofibrillated cellulose, was proposed for viscosupplementation of the intervertebral disc nucleus pulposus [...] Read more.
The development of non-cellularized injectable suspensions of viscous chitosan (CHI) solutions (1.7–3.3% (w/w)), filled with cellulose nanofibers (CNF) (0.02–0.6% (w/w)) of the type nanofibrillated cellulose, was proposed for viscosupplementation of the intervertebral disc nucleus pulposus tissue. The achievement of CNF/CHI formulations which can gel in situ at the disc injection site constitutes a minimally-invasive approach to restore damaged/degenerated discs. We studied physico-chemical aspects of the sol and gel states of the CNF/CHI formulations, including the rheological behavior in relation to injectability (sol state) and fiber mechanical reinforcement (gel state). CNF-CHI interactions could be evidenced by a double flow behavior due to the relaxation of the CHI polymer chains and those interacting with the CNFs. At high shear rates resembling the injection conditions with needles commonly used in surgical treatments, both the reference CHI viscous solutions and those filled with CNFs exhibited similar rheological behavior. The neutralization of the flowing and weakly acidic CNF/CHI suspensions yielded composite hydrogels in which the nanofibers reinforced the CHI matrix. We performed evaluations in relation to the biomedical application, such as the effect of the intradiscal injection of the CNF/CHI formulation in pig and rabbit spine models on disc biomechanics. We showed that the injectable formulations became hydrogels in situ after intradiscal gelation, due to CHI neutralization occurring in contact with the body fluids. No leakage of the injectate through the injection canal was observed and the gelled formulation restored the disc height and loss of mechanical properties, which is commonly related to disc degeneration. Full article
(This article belongs to the Special Issue Chitin and Chitosan: Properties and Applications)
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