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Special Issue "Advances in Marine Chitin and Chitosan"

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A special issue of Marine Drugs (ISSN 1660-3397).

Deadline for manuscript submissions: closed (30 September 2014)

Special Issue Editors

Guest Editor
Prof. Dr. David Harding

Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, 4442, New Zealand
Website | E-Mail
Phone: +6421767565
Interests: hydrogels and other biopolymers
Guest Editor
Dr. Hitoshi Sashiwa

Kaneka Co., Ltd, 5-1-1 Torikai-Nishi, Settsu, Osaka 566-0072 Japan
Website | E-Mail
Phone: +81-72-653-8333
Interests: chemical modification of chitin and chitosan and their biomedical applications

Special Issue Information

Dear Colleagues,

The now considerable research history on chitin started in the 1970s. Since the 1980s, chitin research has progressed significantly over several stages in both fundamental and industrial fields. However, current overviews in recent publications involving chitin and chitosan research advances appear lacking. With the opening of this Special Issue, Advances in Marine Chitin and Chitosan in Marine Drugs, we plan to produce a strong, very exciting issue that will encompass breakthroughs in high value, scientific and industrial chitin and chitosan research.

We look forward very much to your input.

Dr. Hitoshi Sashiwa,
Prof. Dr. David Harding,
Guest Editors

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Marine Drugs is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs).

Print Edition available!
A Print Edition of this Special Issue is available here.

Hardcover: 57.50 CHF*
Pages: 14, 470
*For contributing authors or bulk orders special prices may apply.
Prices include shipping.

Keywords

  • chitin
  • chitosan
  • chito-oligosaccharide
  • glucosamine
  • N-acetyl-D-glucosamine
  • chemical modification
  • controlled drug delivery
  • hydrogels

Related Special Issue

Published Papers (20 papers)

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Research

Jump to: Review

Open AccessArticle Design of Chitosan-Grafted Carbon Nanotubes: Evaluation of How the –OH Functional Group Affects Cs+ Adsorption
Mar. Drugs 2015, 13(5), 3116-3131; doi:10.3390/md13053116
Received: 10 October 2014 / Accepted: 17 December 2014 / Published: 20 May 2015
Cited by 4 | PDF Full-text (1011 KB) | HTML Full-text | XML Full-text
Abstract
In order to explore the effect of –OH functional groups in Cs+ adsorption, we herein used the low temperature plasma-induced grafting method to graft chitosan onto carbon nanotubes (denoted as CTS-g-CNTs), as raw-CNTs have few functional groups and chitosan has a large
[...] Read more.
In order to explore the effect of –OH functional groups in Cs+ adsorption, we herein used the low temperature plasma-induced grafting method to graft chitosan onto carbon nanotubes (denoted as CTS-g-CNTs), as raw-CNTs have few functional groups and chitosan has a large number of –OH functional groups. The synthesized CTS-g-CNT composites were characterized using different techniques. The effect of –OH functional groups in the Cs+ adsorption process was evaluated by comparison of the adsorption properties of raw-CNTs with and without grafting chitosan. The variation of environmental conditions such as pH and contact time was investigated. A comparison of contaminated seawater and simulated groundwater was also evaluated. The results indicated that: (1) the adsorption of Cs+ ions was strongly dependent on pH and the competitive cations; (2) for CNT-based material, the –OH functional groups have a positive effect on Cs+ removal; (3) simulated contaminated groundwater can be used to model contaminated seawater to evaluate the adsorption property of CNTs-based material. These results showed direct observational evidence on the effect of –OH functional groups for Cs+ adsorption. Our findings are important in providing future directions to design and to choose effective material to remedy the removal of radioactive cesium from contaminated groundwater and seawater, crucial for public health and the human social environment. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle Co-Processed Chitin-Mannitol as a New Excipient for Oro-Dispersible Tablets
Mar. Drugs 2015, 13(4), 1739-1764; doi:10.3390/md13041739
Received: 2 November 2014 / Revised: 21 January 2015 / Accepted: 9 February 2015 / Published: 30 March 2015
PDF Full-text (1257 KB) | HTML Full-text | XML Full-text
Abstract
This study describes the preparation, characterization and performance of a novel excipient for use in oro-dispersible tablets (ODT). The excipient (CopCM) consists of chitin and mannitol. The excipient with optimal physicochemical properties was obtained at a chitin: mannitol ratio
[...] Read more.
This study describes the preparation, characterization and performance of a novel excipient for use in oro-dispersible tablets (ODT). The excipient (CopCM) consists of chitin and mannitol. The excipient with optimal physicochemical properties was obtained at a chitin: mannitol ratio of 2:8 (w/w) and produced by roll compaction (RC). Differential scanning calorimetry (DSC), Fourier transform-Infrared (FT-IR), X-ray powder diffraction (XRPD) and scanning electron microscope (SEM) techniques were used to characterize CopCM, in addition to characterization of its powder and ODT dosage form. The effect of particle size distribution of CopCM was investigated and found to have no significant influence on the overall tablet physical properties. The compressibility parameter (a) for CopCM was calculated from a Kawakita plot and found to be higher (0.661) than that of mannitol (0.576) due to the presence of the highly compressible chitin (0.818). Montelukast sodium and domperidone ODTs produced, using CopCM, displayed excellent physicochemical properties. The exceptional binding, fast wetting and superdisintegration properties of CopCM, in comparison with commercially available co-processed ODT excipients, results in a unique multifunctional base which can successfully be used in the formulation of oro-dispersible and fast immediate release tablets. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle Low Molecular Weight Chitosan–Insulin Polyelectrolyte Complex: Characterization and Stability Studies
Mar. Drugs 2015, 13(4), 1765-1784; doi:10.3390/md13041765
Received: 17 December 2014 / Revised: 28 January 2015 / Accepted: 3 February 2015 / Published: 30 March 2015
Cited by 2 | PDF Full-text (671 KB) | HTML Full-text | XML Full-text
Abstract
The aim of the work reported herein was to investigate the effect of various low molecular weight chitosans (LMWCs) on the stability of insulin using USP HPLC methods. Insulin was found to be stable in a polyelectrolyte complex (PEC) consisting of insulin and
[...] Read more.
The aim of the work reported herein was to investigate the effect of various low molecular weight chitosans (LMWCs) on the stability of insulin using USP HPLC methods. Insulin was found to be stable in a polyelectrolyte complex (PEC) consisting of insulin and LMWC in the presence of a Tris-buffer at pH 6.5. In the presence of LMWC, the stability of insulin increased with decreasing molecular weight of LMWC; 13 kDa LMWC was the most efficient molecular weight for enhancing the physical and chemical stability of insulin. Solubilization of insulin-LMWC polyelectrolyte complex (I-LMWC PEC) in a reverse micelle (RM) system, administered to diabetic rats, results in an oral delivery system for insulin with acceptable bioactivity. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle Influence of Molecular Weight and Degree of Deacetylation of Low Molecular Weight Chitosan on the Bioactivity of Oral Insulin Preparations
Mar. Drugs 2015, 13(4), 1710-1725; doi:10.3390/md13041710
Received: 10 December 2014 / Revised: 19 January 2015 / Accepted: 15 February 2015 / Published: 27 March 2015
Cited by 4 | PDF Full-text (922 KB) | HTML Full-text | XML Full-text
Abstract
The objective of the present study was to prepare and characterize low molecular weight chitosan (LMWC) with different molecular weight and degrees of deacetylation (DDA) and to optimize their use in oral insulin nano delivery systems. Water in oil nanosized systems containing LMWC-insulin
[...] Read more.
The objective of the present study was to prepare and characterize low molecular weight chitosan (LMWC) with different molecular weight and degrees of deacetylation (DDA) and to optimize their use in oral insulin nano delivery systems. Water in oil nanosized systems containing LMWC-insulin polyelectrolyte complexes were constructed and their ability to reduce blood glucose was assessed in vivo on diabetic rats. Upon acid depolymerization and testing by viscosity method, three molecular weights of LMWC namely, 1.3, 13 and 18 kDa were obtained. As for the DDA, three LMWCs of 55%, 80% and 100% DDA were prepared and characterized by spectroscopic methods for each molecular weight. The obtained LMWCs showed different morphological and in silico patterns. Following complexation of LMWCs with insulin, different aggregation sizes were obtained. Moreover, the in vivo tested formulations showed different activities of blood glucose reduction. The highest glucose reduction was achieved with 1.3 kDa LMWC of 55% DDA. The current study emphasizes the importance of optimizing the molecular weight along with the DDA of the incorporated LMWC in oral insulin delivery preparations in order to ensure the highest performance of such delivery systems. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle Squid Pen Chitin Chitooligomers as Food Colorants Absorbers
Mar. Drugs 2015, 13(1), 681-696; doi:10.3390/md13010681
Received: 28 August 2014 / Accepted: 9 January 2015 / Published: 20 January 2015
Cited by 3 | PDF Full-text (544 KB) | HTML Full-text | XML Full-text
Abstract
One of the most promising applications of chitosanase is the conversion of chitinous biowaste into bioactive chitooligomers (COS). TKU033 chitosanase was induced from squid pen powder (SPP)-containing Bacillus cereus TKU033 medium and purified by ammonium sulfate precipitation and column chromatography. The enzyme was
[...] Read more.
One of the most promising applications of chitosanase is the conversion of chitinous biowaste into bioactive chitooligomers (COS). TKU033 chitosanase was induced from squid pen powder (SPP)-containing Bacillus cereus TKU033 medium and purified by ammonium sulfate precipitation and column chromatography. The enzyme was relatively more thermostable in the presence of the substrate and had an activity of 93% at 50 °C in a pH 5 buffer solution for 60 min. Furthermore, the enzyme used for the COS preparation was also studied. The enzyme products revealed various mixtures of COS that with different degrees of polymerization (DP), ranging from three to nine. In the culture medium, the fermented SPP was recovered, and it displayed a better adsorption rate (up to 96%) for the disperse dyes than the water-soluble food colorants, Allura Red AC (R40) and Tartrazne (Y4). Fourier transform-infrared spectroscopic (FT-IR) analysis proved that the adsorption of the dyes onto fermented SPP was a physical adsorption. Results also showed that fermented SPP was a favorable adsorber and could be employed as low-cost alternative for dye removal in wastewater treatment. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessArticle Chitosan in Mucoadhesive Drug Delivery: Focus on Local Vaginal Therapy
Mar. Drugs 2015, 13(1), 222-236; doi:10.3390/md13010222
Received: 30 October 2014 / Accepted: 25 December 2014 / Published: 7 January 2015
Cited by 4 | PDF Full-text (393 KB) | HTML Full-text | XML Full-text
Abstract
Mucoadhesive drug therapy destined for localized drug treatment is gaining increasing importance in today’s drug development. Chitosan, due to its known biodegradability, bioadhesiveness and excellent safety profile offers means to improve mucosal drug therapy. We have used chitosan as mucoadhesive polymer to develop
[...] Read more.
Mucoadhesive drug therapy destined for localized drug treatment is gaining increasing importance in today’s drug development. Chitosan, due to its known biodegradability, bioadhesiveness and excellent safety profile offers means to improve mucosal drug therapy. We have used chitosan as mucoadhesive polymer to develop liposomes able to ensure prolonged residence time at vaginal site. Two types of mucoadhesive liposomes, namely the chitosan-coated liposomes and chitosan-containing liposomes, where chitosan is both embedded and surface-available, were made of soy phosphatidylcholine with entrapped fluorescence markers of two molecular weights, FITC-dextran 4000 and 20,000, respectively. Both liposomal types were characterized for their size distribution, zeta potential, entrapment efficiency and the in vitro release profile, and compared to plain liposomes. The proof of chitosan being both surface-available as well as embedded into the liposomes in the chitosan-containing liposomes was found. The capability of the surface-available chitosan to interact with the model porcine mucin was confirmed for both chitosan-containing and chitosan-coated liposomes implying potential mucoadhesive behavior. Chitosan-containing liposomes were shown to be superior in respect to the simplicity of preparation, FITC-dextran load, mucoadhesiveness and in vitro release and are expected to ensure prolonged residence time on the vaginal mucosa providing localized sustained release of entrapped model substances. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle Does the Use of Chitosan Contribute to Oxalate Kidney Stone Formation?
Mar. Drugs 2015, 13(1), 141-158; doi:10.3390/md13010141
Received: 19 June 2014 / Accepted: 30 October 2014 / Published: 29 December 2014
Cited by 3 | PDF Full-text (886 KB) | HTML Full-text | XML Full-text
Abstract
Chitosan is widely used in the biomedical field due its chemical and pharmacological properties. However, intake of chitosan results in renal tissue accumulation of chitosan and promotes an increase in calcium excretion. On the other hand, the effect of chitosan on the formation
[...] Read more.
Chitosan is widely used in the biomedical field due its chemical and pharmacological properties. However, intake of chitosan results in renal tissue accumulation of chitosan and promotes an increase in calcium excretion. On the other hand, the effect of chitosan on the formation of calcium oxalate crystals (CaOx) has not been described. In this work, we evaluated the antioxidant capacity of chitosan and its interference in the formation of CaOx crystals in vitro. Here, the chitosan obtained commercially had its identity confirmed by nuclear magnetic resonance and infrared spectroscopy. In several tests, this chitosan showed low or no antioxidant activity. However, it also showed excellent copper-chelating activity. In vitro, chitosan acted as an inducer mainly of monohydrate CaOx crystal formation, which is more prevalent in patients with urolithiasis. We also observed that chitosan modifies the morphology and size of these crystals, as well as changes the surface charge of the crystals, making them even more positive, which can facilitate the interaction of these crystals with renal cells. Chitosan greatly influences the formation of crystals in vitro, and in vivo analyses should be conducted to assess the risk of using chitosan. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessArticle The Influence of 1-Butanol and Trisodium Citrate Ion on Morphology and Chemical Properties of Chitosan-Based Microcapsules during Rigidification by Alkali Treatment
Mar. Drugs 2014, 12(12), 5801-5816; doi:10.3390/md12125801
Received: 9 October 2014 / Revised: 17 November 2014 / Accepted: 19 November 2014 / Published: 2 December 2014
Cited by 2 | PDF Full-text (1360 KB) | HTML Full-text | XML Full-text
Abstract
Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed
[...] Read more.
Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed by alternate additions of SDS and Chi solutions in an emulsion through electrostatic interaction. No chemical cross-linker was used in the study and the multilayer shell membrane was formed by ionic gelation using Chi and SDS. The rigidification of the shell membrane of microcapsules was achieved by alkali treatment in the presence of a small amount of 1-butanol to reduce aggregation. A trisodium citrate solution was used to stabilize the charge of microcapsules by ionic cross-linking. Effects of butanol during alkali treatment and citrate in post alkali treatment were monitored in terms of morphology and the chemical properties of microcapsules. Various characterization techniques revealed that the aggregation was decreased and surface roughness was increased with layer formation. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessArticle Mucoadhesive Microparticles for Gastroretentive Delivery: Preparation, Biodistribution and Targeting Evaluation
Mar. Drugs 2014, 12(12), 5764-5787; doi:10.3390/md12125764
Received: 16 October 2014 / Revised: 14 November 2014 / Accepted: 19 November 2014 / Published: 1 December 2014
Cited by 2 | PDF Full-text (931 KB) | HTML Full-text | XML Full-text
Abstract
The aim of this research was to prepare and characterize alginate-chitosan mucoadhesive microparticles containing puerarin. The microparticles were prepared by an emulsification-internal gelatin method using a combination of chitosan and Ca2+ as cationic components and alginate as anions. Surface morphology, particle size,
[...] Read more.
The aim of this research was to prepare and characterize alginate-chitosan mucoadhesive microparticles containing puerarin. The microparticles were prepared by an emulsification-internal gelatin method using a combination of chitosan and Ca2+ as cationic components and alginate as anions. Surface morphology, particle size, drug loading, encapsulation efficiency and swelling ratio, in vitro drug released, in vitro evaluation of mucoadhesiveness and Fluorescence imaging of the gastrointestinal tract were determined. After optimization of the formulation, the encapsulation efficiency was dramatically increased from 70.3% to 99.2%, and a highly swelling ratio was achieved with a change in particle size from 50.3 ± 11.2 μm to 124.7 ± 25.6 μm. In ethanol induced gastric ulcers, administration of puerarin mucoadhesive microparticles at doses of 150 mg/kg, 300 mg/kg, 450 mg/kg and 600 mg/kg body weight prior to ethanol ingestion significantly protected the stomach ulceration. Consequently, significant changes were observed in inflammatory cytokines, such as prostaglandin E2 (PGE2), tumor necrosis factor (TNF-α), interleukin 6 (IL-6), and interleukin1β (IL-1β), in stomach tissues compared with the ethanol control group. In conclusion, core-shell type pH-sensitive mucoadhesive microparticles loaded with puerarin could enhance puerarin bioavailability and have the potential to alleviate ethanol-mediated gastric ulcers. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle Delivery of Berberine Using Chitosan/Fucoidan-Taurine Conjugate Nanoparticles for Treatment of Defective Intestinal Epithelial Tight Junction Barrier
Mar. Drugs 2014, 12(11), 5677-5697; doi:10.3390/md12115677
Received: 6 September 2014 / Revised: 31 October 2014 / Accepted: 13 November 2014 / Published: 24 November 2014
Cited by 13 | PDF Full-text (1156 KB) | HTML Full-text | XML Full-text
Abstract
Bacterial-derived lipopolysaccharides (LPS) can cause defective intestinal barrier function and play an important role in the development of inflammatory bowel disease. In this study, a nanocarrier based on chitosan and fucoidan was developed for oral delivery of berberine (Ber). A sulfonated fucoidan, fucoidan-taurine
[...] Read more.
Bacterial-derived lipopolysaccharides (LPS) can cause defective intestinal barrier function and play an important role in the development of inflammatory bowel disease. In this study, a nanocarrier based on chitosan and fucoidan was developed for oral delivery of berberine (Ber). A sulfonated fucoidan, fucoidan-taurine (FD-Tau) conjugate, was synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy. The FD-Tau conjugate was self-assembled with berberine and chitosan (CS) to form Ber-loaded CS/FD-Tau complex nanoparticles with high drug loading efficiency. Berberine release from the nanoparticles had fast release in simulated intestinal fluid (SIF, pH 7.4), while the release was slow in simulated gastric fluid (SGF, pH 2.0). The effect of the berberine-loaded nanoparticles in protecting intestinal tight-junction barrier function against nitric oxide and inflammatory cytokines released from LPS-stimulated macrophage was evaluated by determining the transepithelial electrical resistance (TEER) and paracellular permeability of a model macromolecule fluorescein isothiocyanate-dextran (FITC-dextran) in a Caco-2 cells/RAW264.7 cells co-culture system. Inhibition of redistribution of tight junction ZO-1 protein by the nanoparticles was visualized using confocal laser scanning microscopy (CLSM). The results suggest that the nanoparticles may be useful for local delivery of berberine to ameliorate LPS-induced intestinal epithelia tight junction disruption, and that the released berberine can restore barrier function in inflammatory and injured intestinal epithelial. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle Synthesis and Rheological Characterization of Water-Soluble Glycidyltrimethylammonium-Chitosan
Mar. Drugs 2014, 12(11), 5547-5562; doi:10.3390/md12115547
Received: 9 October 2014 / Revised: 5 November 2014 / Accepted: 12 November 2014 / Published: 20 November 2014
Cited by 2 | PDF Full-text (744 KB) | HTML Full-text | XML Full-text
Abstract
In this study, chitosan (CS) grafted by glycidyltrimethylammonium chloride (GTMAC) to form GTMAC-CS was synthesized, chemically identified, and rheologically characterized. The Maxwell Model can be applied to closely simulate the dynamic rheological performance of the chitosan and the GTMAC-CS solutions, revealing a single
[...] Read more.
In this study, chitosan (CS) grafted by glycidyltrimethylammonium chloride (GTMAC) to form GTMAC-CS was synthesized, chemically identified, and rheologically characterized. The Maxwell Model can be applied to closely simulate the dynamic rheological performance of the chitosan and the GTMAC-CS solutions, revealing a single relaxation time pertains to both systems. The crossover point of G′ and Gʺ shifted toward lower frequencies as the CS concentration increased but remained almost constant frequencies as the GTMAC-CS concentration increased, indicating the solubility of GTMAC-CS in water is good enough to diminish influence from the interaction among polymer chains so as to ensure the relaxation time is independent of the concentration. A frequency–concentration superposition master curve of the CS and GTMAC-CS solutions was subsequently proposed and well fitted with the experimental results. Finally, the sol-gel transition of CS is 8.5 weight % (wt %), while that of GTMAC-CS is 20 wt %, reconfirming the excellent water solubility of the latter. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessArticle The Effect of Substituent, Degree of Acetylation and Positioning of the Cationic Charge on the Antibacterial Activity of Quaternary Chitosan Derivatives
Mar. Drugs 2014, 12(8), 4635-4658; doi:10.3390/md12084635
Received: 23 June 2014 / Revised: 23 July 2014 / Accepted: 23 July 2014 / Published: 21 August 2014
Cited by 12 | PDF Full-text (1834 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A series of water-soluble cationic chitosan derivatives were prepared by chemoselective functionalization at the amino group of five different parent chitosans having varying degrees of acetylation and molecular weight. The quaternary moieties were introduced at different alkyl spacer lengths from the polymer backbone
[...] Read more.
A series of water-soluble cationic chitosan derivatives were prepared by chemoselective functionalization at the amino group of five different parent chitosans having varying degrees of acetylation and molecular weight. The quaternary moieties were introduced at different alkyl spacer lengths from the polymer backbone (C-0, C-2 and C-6) with the aid of 3,6-di-O-tert-butyldimethylsilyl protection of the chitosan backbone, thus allowing full (100%) substitution of the free amino groups. All of the derivatives were characterized using 1H-NMR, 1H-1H COSY and FT-IR spectroscopy, while molecular weight was determined by GPC. Antibacterial activity was investigated against Gram positive S. aureus and Gram negative E. coli. The relationship between structure and activity/toxicity was defined, considering the effect of the cationic group’s structure and its distance from the polymer backbone, as well as the degree of acetylation within a molecular weight range of 7–23 kDa for the final compounds. The N,N,N-trimethyl chitosan with 100% quaternization showed the highest antibacterial activity with moderate cytotoxicity, while increasing the spacer length reduced the activity. Trimethylammoniumyl quaternary ammonium moieties contributed more to activity than 1-pyridiniumyl moieties. In general, no trend in the antibacterial activity of the compounds with increasing molecular weight or degree of acetylation up to 34% was observed. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Review

Jump to: Research

Open AccessReview Chitin and Chitosan as Direct Compression Excipients in Pharmaceutical Applications
Mar. Drugs 2015, 13(3), 1519-1547; doi:10.3390/md13031519
Received: 18 December 2014 / Revised: 9 January 2015 / Accepted: 9 February 2015 / Published: 19 March 2015
Cited by 7 | PDF Full-text (912 KB) | HTML Full-text | XML Full-text
Abstract
Despite the numerous uses of chitin and chitosan as new functional materials of high potential in various fields, they are still behind several directly compressible excipients already dominating pharmaceutical applications. There are, however, new attempts to exploit chitin and chitosan in co-processing techniques
[...] Read more.
Despite the numerous uses of chitin and chitosan as new functional materials of high potential in various fields, they are still behind several directly compressible excipients already dominating pharmaceutical applications. There are, however, new attempts to exploit chitin and chitosan in co-processing techniques that provide a product with potential to act as a direct compression (DC) excipient. This review outlines the compression properties of chitin and chitosan in the context of DC pharmaceutical applications. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessReview Chitin and Chitosan Preparation from Marine Sources. Structure, Properties and Applications
Mar. Drugs 2015, 13(3), 1133-1174; doi:10.3390/md13031133
Received: 26 December 2014 / Accepted: 16 February 2015 / Published: 2 March 2015
Cited by 57 | PDF Full-text (816 KB) | HTML Full-text | XML Full-text
Abstract
This review describes the most common methods for recovery of chitin from marine organisms. In depth, both enzymatic and chemical treatments for the step of deproteinization are compared, as well as different conditions for demineralization. The conditions of chitosan preparation are also discussed,
[...] Read more.
This review describes the most common methods for recovery of chitin from marine organisms. In depth, both enzymatic and chemical treatments for the step of deproteinization are compared, as well as different conditions for demineralization. The conditions of chitosan preparation are also discussed, since they significantly impact the synthesis of chitosan with varying degree of acetylation (DA) and molecular weight (MW). In addition, the main characterization techniques applied for chitin and chitosan are recalled, pointing out the role of their solubility in relation with the chemical structure (mainly the acetyl group distribution along the backbone). Biological activities are also presented, such as: antibacterial, antifungal, antitumor and antioxidant. Interestingly, the relationship between chemical structure and biological activity is demonstrated for chitosan molecules with different DA and MW and homogeneous distribution of acetyl groups for the first time. In the end, several selected pharmaceutical and biomedical applications are presented, in which chitin and chitosan are recognized as new biomaterials taking advantage of their biocompatibility and biodegradability. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessReview Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review
Mar. Drugs 2015, 13(1), 312-337; doi:10.3390/md13010312
Received: 9 November 2014 / Accepted: 30 December 2014 / Published: 9 January 2015
Cited by 38 | PDF Full-text (1308 KB) | HTML Full-text | XML Full-text
Abstract
Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides,
[...] Read more.
Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase). Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessReview Design of Chitosan and Its Water Soluble Derivatives-Based Drug Carriers with Polyelectrolyte Complexes
Mar. Drugs 2014, 12(12), 6236-6253; doi:10.3390/md12126236
Received: 9 October 2014 / Revised: 11 December 2014 / Accepted: 12 December 2014 / Published: 19 December 2014
Cited by 7 | PDF Full-text (535 KB) | HTML Full-text | XML Full-text
Abstract
Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in
[...] Read more.
Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessReview Glycol Chitosan-Based Fluorescent Theranostic Nanoagents for Cancer Therapy
Mar. Drugs 2014, 12(12), 6038-6057; doi:10.3390/md12126038
Received: 9 October 2014 / Revised: 27 November 2014 / Accepted: 27 November 2014 / Published: 17 December 2014
Cited by 8 | PDF Full-text (1449 KB) | HTML Full-text | XML Full-text
Abstract
Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging
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Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging agents and also monitor the response to therapy. Polymeric nanosystems have been intensively explored for biomedical applications to diagnose and treat various cancers. In recent years, glycol chitosan-based nanoagents have been developed as dual-purpose materials for simultaneous diagnosis and therapy. They have shown great potential in cancer therapies, such as chemotherapeutics and nucleic acid and photodynamic therapies. In this review, we summarize the recent progress and potential applications of glycol chitosan-based fluorescent theranostic nanoagents for cancer treatments and discuss their possible underlying mechanisms. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
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Open AccessReview Preparation of Chitosan Nanocompositeswith a Macroporous Structure by Unidirectional Freezing and Subsequent Freeze-Drying
Mar. Drugs 2014, 12(11), 5619-5642; doi:10.3390/md12115619
Received: 11 October 2014 / Revised: 12 November 2014 / Accepted: 13 November 2014 / Published: 24 November 2014
Cited by 10 | PDF Full-text (2235 KB) | HTML Full-text | XML Full-text
Abstract
Chitosan is the N-deacetylated derivative of chitin, a naturally abundant mucopolysaccharide that consists of 2-acetamido-2-deoxy-β-d-glucose through a β (1→4) linkage and is found in nature as the supporting material of crustaceans, insects, etc. Chitosan has been strongly recommended as a suitable functional
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Chitosan is the N-deacetylated derivative of chitin, a naturally abundant mucopolysaccharide that consists of 2-acetamido-2-deoxy-β-d-glucose through a β (1→4) linkage and is found in nature as the supporting material of crustaceans, insects, etc. Chitosan has been strongly recommended as a suitable functional material because of its excellent biocompatibility, biodegradability, non-toxicity, and adsorption properties. Boosting all these excellent properties to obtain unprecedented performances requires the core competences of materials chemists to design and develop novel processing strategies that ultimately allow tailoring the structure and/or the composition of the resulting chitosan-based materials. For instance, the preparation of macroporous materials is challenging in catalysis, biocatalysis and biomedicine, because the resulting materials will offer a desirable combination of high internal reactive surface area and straightforward molecular transport through broad “highways” leading to such a surface. Moreover, chitosan-based composites made of two or more distinct components will produce structural or functional properties not present in materials composed of one single component. Our group has been working lately on cryogenic processes based on the unidirectional freezing of water slurries and/or hydrogels, the subsequent freeze-drying of which produce macroporous materials with a well-patterned structure. We have applied this process to different gels and colloidal suspensions of inorganic, organic, and hybrid materials. In this review, we will describe the application of the process to chitosan solutions and gels typically containing a second component (e.g., metal and ceramic nanoparticles, or carbon nanotubes) for the formation of chitosan nanocomposites with a macroporous structure. We will also discuss the role played by this tailored composition and structure in the ultimate performance of these materials. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessReview Emerging Biomedical Applications of Nano-Chitins and Nano-Chitosans Obtained via Advanced Eco-Friendly Technologies from Marine Resources
Mar. Drugs 2014, 12(11), 5468-5502; doi:10.3390/md12115468
Received: 10 October 2014 / Revised: 2 November 2014 / Accepted: 3 November 2014 / Published: 19 November 2014
Cited by 26 | PDF Full-text (1990 KB) | HTML Full-text | XML Full-text
Abstract
The present review article is intended to direct attention to the technological advances made in the 2010–2014 quinquennium for the isolation and manufacture of nanofibrillar chitin and chitosan. Otherwise called nanocrystals or whiskers, n-chitin and n-chitosan are obtained either by mechanical chitin disassembly
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The present review article is intended to direct attention to the technological advances made in the 2010–2014 quinquennium for the isolation and manufacture of nanofibrillar chitin and chitosan. Otherwise called nanocrystals or whiskers, n-chitin and n-chitosan are obtained either by mechanical chitin disassembly and fibrillation optionally assisted by sonication, or by e-spinning of solutions of polysaccharides often accompanied by poly(ethylene oxide) or poly(caprolactone). The biomedical areas where n-chitin may find applications include hemostasis and wound healing, regeneration of tissues such as joints and bones, cell culture, antimicrobial agents, and dermal protection. The biomedical applications of n-chitosan include epithelial tissue regeneration, bone and dental tissue regeneration, as well as protection against bacteria, fungi and viruses. It has been found that the nano size enhances the performances of chitins and chitosans in all cases considered, with no exceptions. Biotechnological approaches will boost the applications of the said safe, eco-friendly and benign nanomaterials not only in these fields, but also for biosensors and in targeted drug delivery areas. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available
Open AccessReview Bioproduction of Chitooligosaccharides: Present and Perspectives
Mar. Drugs 2014, 12(11), 5328-5356; doi:10.3390/md12115328
Received: 19 August 2014 / Revised: 20 October 2014 / Accepted: 21 October 2014 / Published: 28 October 2014
Cited by 18 | PDF Full-text (357 KB) | HTML Full-text | XML Full-text
Abstract
Chitin and chitosan oligosaccharides (COS) have been traditionally obtained by chemical digestion with strong acids. In light of the difficulties associated with these traditional production processes, environmentally compatible and reproducible production alternatives are desirable. Unlike chemical digestion, biodegradation of chitin and chitosan by
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Chitin and chitosan oligosaccharides (COS) have been traditionally obtained by chemical digestion with strong acids. In light of the difficulties associated with these traditional production processes, environmentally compatible and reproducible production alternatives are desirable. Unlike chemical digestion, biodegradation of chitin and chitosan by enzymes or microorganisms does not require the use of toxic chemicals or excessive amounts of wastewater. Enzyme preparations with chitinase, chitosanase, and lysozymeare primarily used to hydrolyze chitin and chitosan. Commercial preparations of cellulase, protease, lipase, and pepsin provide another opportunity for oligosaccharide production. In addition to their hydrolytic activities, the transglycosylation activity of chitinolytic enzymes might be exploited for the synthesis of desired chitin oligomers and their derivatives. Chitin deacetylase is also potentially useful for the preparation of oligosaccharides. Recently, direct production of oligosaccharides from chitin and crab shells by a combination of mechanochemical grinding and enzymatic hydrolysis has been reported. Together with these, other emerging technologies such as direct degradation of chitin from crustacean shells and microbial cell walls, enzymatic synthesis of COS from small building blocks, and protein engineering technology for chitin-related enzymes have been discussed as the most significant challenge for industrial application. Full article
(This article belongs to the Special Issue Advances in Marine Chitin and Chitosan) Print Edition available

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