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Chitin and Chitosan Derivatives: Biological Activities and Application

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Medicinal Chemistry".

Deadline for manuscript submissions: closed (15 October 2017) | Viewed by 99795

Special Issue Editor

Faculty of Pharmaceutical Sciences, School of Health Sciences, University of Iceland, Hofsvallagata 53, IS-107 Reykjavík, Iceland
Interests: chitosan derivatives; chitosan conjugates; antimicrobials; drug delivery; nanoparticles; mathematical modeling
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Chitin and chitosan (poly β-1,4 linked D-glucosamine and N-acetyl-D-glucosamine) are biocompatible biopolymers with some unique biological properties. They have found applications in a number of fields, including medicine, pharmaceuticals, food processing, cosmetics, and agriculture. The use of these biopolymers is growing and research activities continue to increase; however, there are certain limitations for the use unmodified chitin and chitosan, mainly because the structural variation of the unmodified polymer is restricted to changes in the degree of N-acetylation and the molecular weight. Thus, there is more focus on the chemical modification of chitin and chitosan to make chitosan derivatives (conjugates). This promises to significantly expand utility in various fields, where these biopolymers have been used, and will also lead to novel applications. Many types of functional groups, including lipophilic and charged groups, have been introduced in order to enhance the bioactivity or desired physicochemical properties. Bioactive moieties, such as drugs, natural compounds, and various biomacromolecules, can be conjugated to the polymer backbone to give new types of materials that can be designed to function as drug delivery systems, components for constructing nanoparticles that can target certain cell types, imaging agents, and materials that have been tailored for certain regenerative properties. Chemically-reactive groups can also be introduced to promote polymerization or non-covalent bonding between polymer chains. These materials can be used to prepare stable bioactive coatings, hydrogels, and other types of complex biomaterials. To fully reach the potential of this new field, there are number of challenges that researchers must overcome. There is still a great deal of room to develop new efficient synthesis and grafting procedures. In order to further the understanding of the structural activity and structure property relationships, improved tools and methods for accurate structural and physicochemical characterization will be essential. A better understanding of how bioactivity can be improved, without increasing the potential for of adverse effects, is needed. In response to these developments, and in order to encourage researchers from different backgrounds to share the results, Molecules is launching this Special Issue. Topics can include, but are not limited to:

  • Synthesis
  • Grafting
  • Polymerization
  • Photochemistry
  • Enzyme Catalyzed Reactions
  • Reaction Mechanism
  • Structure Characterization (including NMR)
  • Physicochemical characteristics
  • Structure property relationship
  • Bioactivity
  • Antimicrobial properties
  • Anticancer properties
  • Regenerative properties
  • Structure Activity Relationship
  • Drug Delivery
  • Gene Delivery
  • Metabolism
  • Toxicology
  • Nanoparticles
  • Biomaterials
  • Coatings
  • Gels
  • Composite materials

Prof. Dr. Már Másson
Guest Editor

Manuscript Submission Information

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Keywords

  • Chitosan conjugates
  • Chitosan derivatives
  • Chitin derivatives
  • Medicina chemistry
  • Polymer chemistry
  • Bioactivity

References

  1. Pestov, A.; Bratskaya, S. Chitosan and Its Derivatives as Highly Efficient Polymer Ligands. Molecules 2016, 21, 330. 
  2. Ramirez-Estrada, K.; Vidal-Limon, H.; Hidalgo, D.; Moyano, E.; Golenioswki, M.; Cusidó, R.M.; Palazon, J. Elicitation, an Effective Strategy for the Biotechnological Production of Bioactive High-Added Value Compounds in Plant Cell Factories. Molecules 2016, 21, 182. 
  3. Ruocco, N.; Costantini, S.; Guariniello, S.; Costantini, M. Polysaccharides from the Marine Environment with Pharmacological, Cosmeceutical and Nutraceutical Potential. Molecules 2016, 21, 551. 
  4. Ohkawa, K. Nanofibers of Cellulose and Its Derivatives Fabricated Using Direct Electrospinning. Molecules 2015, 20, 9139-9154. 
  5. Ifuku, S. Chitin and Chitosan Nanofibers: Preparation and Chemical Modifications. Molecules 2014, 19, 18367-18380.

Published Papers (15 papers)

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Research

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12 pages, 5949 KiB  
Article
Preparation, Characterization and Biological Applications of Biosynthesized Silver Nanoparticles with Chitosan-Fucoidan Coating
by Jayachandran Venkatesan, Sandeep Kumar Singh, Sukumaran Anil, Se-Kwon Kim and Min Suk Shim
Molecules 2018, 23(6), 1429; https://doi.org/10.3390/molecules23061429 - 12 Jun 2018
Cited by 87 | Viewed by 8587
Abstract
Silver nanoparticles (AgNPs) are gaining a great deal of attention in biomedical applications due to their unique physicochemical properties. In this study, green synthesis of AgNPs was developed using seaweed polysaccharide fucoidan. The AgNPs were further coated with chitosan to form an electrolyte [...] Read more.
Silver nanoparticles (AgNPs) are gaining a great deal of attention in biomedical applications due to their unique physicochemical properties. In this study, green synthesis of AgNPs was developed using seaweed polysaccharide fucoidan. The AgNPs were further coated with chitosan to form an electrolyte complex on the surface. The developed chitosan–fucoidan complex-coated AgNPs were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). FT-IR results suggested strong polyelectrolyte complexation between fucoidan and chitosan. The developed chitosan–fucoidan complex-coated AgNPs significantly inhibited microbial growth. Moreover, the AgNPs showed efficient anticancer activity in human cervical cancer cells (HeLa). This study demonstrated that chitosan–fucoidan complex-coated AgNPs hold high potential for food and cosmeceutical applications. Full article
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16 pages, 4257 KiB  
Article
Preparation of Well-Dispersed Chitosan/Alginate Hollow Multilayered Microcapsules for Enhanced Cellular Internalization
by Carla Ribeiro, João Borges, Ana M. S. Costa, Vítor M. Gaspar, Verónica De Zea Bermudez and João F. Mano
Molecules 2018, 23(3), 625; https://doi.org/10.3390/molecules23030625 - 10 Mar 2018
Cited by 32 | Viewed by 6113
Abstract
Hollow multilayered capsules have shown massive potential for being used in the biomedical and biotechnology fields, in applications such as cellular internalization, intracellular trafficking, drug delivery, or tissue engineering. In particular, hollow microcapsules, developed by resorting to porous calcium carbonate sacrificial templates, natural-origin [...] Read more.
Hollow multilayered capsules have shown massive potential for being used in the biomedical and biotechnology fields, in applications such as cellular internalization, intracellular trafficking, drug delivery, or tissue engineering. In particular, hollow microcapsules, developed by resorting to porous calcium carbonate sacrificial templates, natural-origin building blocks and the prominent Layer-by-Layer (LbL) technology, have attracted increasing attention owing to their key features. However, these microcapsules revealed a great tendency to aggregate, which represents a major hurdle when aiming for cellular internalization and intracellular therapeutics delivery. Herein, we report the preparation of well-dispersed polysaccharide-based hollow multilayered microcapsules by combining the LbL technique with an optimized purification process. Cationic chitosan (CHT) and anionic alginate (ALG) were chosen as the marine origin polysaccharides due to their biocompatibility and structural similarity to the extracellular matrices of living tissues. Moreover, the inexpensive and highly versatile LbL technology was used to fabricate core-shell microparticles and hollow multilayered microcapsules, with precise control over their composition and physicochemical properties, by repeating the alternate deposition of both materials. The microcapsules’ synthesis procedure was optimized to extensively reduce their natural aggregation tendency, as shown by the morphological analysis monitored by advanced microscopy techniques. The well-dispersed microcapsules showed an enhanced uptake by fibroblasts, opening new perspectives for cellular internalization. Full article
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16 pages, 1977 KiB  
Article
Assessment of Chitosan-Based Hydrogel and Photodynamic Inactivation against Propionibacterium acnes
by Maria Lucia Frade, Sarah Raquel De Annunzio, Giovana Maria Fioramonti Calixto, Francesca Damiani Victorelli, Marlus Chorilli and Carla Raquel Fontana
Molecules 2018, 23(2), 473; https://doi.org/10.3390/molecules23020473 - 22 Feb 2018
Cited by 39 | Viewed by 4344
Abstract
Chitosan (CH) is a biopolymer that exhibits a number of interesting properties such as anti-inflammatory and antibacterial activity and is also a promising platform for the incorporation of photosensitizing agents. This study aimed to evaluate the efficacy of antimicrobial activity of chitosan hydrogel [...] Read more.
Chitosan (CH) is a biopolymer that exhibits a number of interesting properties such as anti-inflammatory and antibacterial activity and is also a promising platform for the incorporation of photosensitizing agents. This study aimed to evaluate the efficacy of antimicrobial activity of chitosan hydrogel formulation alone and in combination with the methylene blue (MB) associated with antimicrobial photodynamic therapy (aPDT) against planktonic and biofilm phase of Propionibacterium acnes. Suspensions were sensitized with 12.5, 25.0, 37.5, 50.0 μg/mL of MB for 10 min and biofilms to 75, 100 and 150 μg/mL for 30 min then exposed to red light (660 nm) at 90 J/cm2 and 150 J/cm2 respectively. After treatments, survival fractions were calculated by counting the number of colony-forming units. The lethal effect of aPDT associated with CH hydrogel in planktonic phase was achieved with 12.5 µg/mL MB and 1.9 log10 biofilm reduction using 75 µg/mL MB. Rheological studies showed that formulations exhibited pseudoplastic non-Newtonian behavior without thixotropy. Bioadhesion test evidenced that the formulations are highly adhesive to skin and the incorporation of MB did not influence the bioadhesive force of the formulations. Full article
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4218 KiB  
Article
Response of Ustilago maydis against the Stress Caused by Three Polycationic Chitin Derivatives
by Dario Rafael Olicón-Hernández, Cristina Uribe-Alvarez, Salvador Uribe-Carvajal, Juan Pablo Pardo and Guadalupe Guerra-Sánchez
Molecules 2017, 22(12), 1745; https://doi.org/10.3390/molecules22121745 - 07 Dec 2017
Cited by 8 | Viewed by 4418
Abstract
Chitosan is a stressing molecule that affects the cells walls and plasma membrane of fungi. For chitosan derivatives, the action mode is not clear. In this work, we used the yeast Ustilago maydis to study the effects of these molecules on the plasma [...] Read more.
Chitosan is a stressing molecule that affects the cells walls and plasma membrane of fungi. For chitosan derivatives, the action mode is not clear. In this work, we used the yeast Ustilago maydis to study the effects of these molecules on the plasma membrane, focusing on physiologic and stress responses to chitosan (CH), oligochitosan (OCH), and glycol-chitosan (GCH). Yeasts were cultured with each of these molecules at 1 mg·mL−1 in minimal medium. To compare plasma membrane damage, cells were cultivated in isosmolar medium. Membrane potential (Δψ) as well as oxidative stress were measured. Changes in the total plasma membrane phospholipid and protein profiles were analyzed using standard methods, and fluorescence-stained mitochondria were observed. High osmolarity did not protect against CH inhibition and neither affected membrane potential. The OCH did produce higher oxidative stress. The effects of these molecules were evidenced by modifications in the plasma membrane protein profile. Also, mitochondrial damage was evident for CH and OCH, while GCH resulted in thicker cells with fewer mitochondria and higher glycogen accumulation. Full article
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2096 KiB  
Article
Biodegradable Chitosan Decreases the Immune Response to Trichinella spiralis in Mice
by Klaudia Brodaczewska, Natalia Wolaniuk, Katarzyna Lewandowska, Katarzyna Donskow-Łysoniewska and Maria Doligalska
Molecules 2017, 22(11), 2008; https://doi.org/10.3390/molecules22112008 - 18 Nov 2017
Cited by 12 | Viewed by 5180
Abstract
The purpose of this study was to evaluate the potential of chitosan units released during natural degradation of the polymer to activate the immune system against T. spiralis infection. High molecular weight chitosan was injected intraperitoneally into C57BL/6 mice. Flow cytometry and cytokine [...] Read more.
The purpose of this study was to evaluate the potential of chitosan units released during natural degradation of the polymer to activate the immune system against T. spiralis infection. High molecular weight chitosan was injected intraperitoneally into C57BL/6 mice. Flow cytometry and cytokine concentration, measured by ELISA, were used to characterize peritoneal cell populations during T. spiralis infection. The strong chemo-attractive properties of chitosan caused considerable infiltration into the peritoneal cavity of CD11b+ cells, with reduced expression of MHC class II, CD80, CD86, Dectin-1 or CD23 receptors in comparison to T. spiralis-infected mice. After prolonged chitosan biodegradation, cell populations expressing IL-4R, MR and Dectin-1 receptors were found to coexist with elevated IL-6, IL-10, TGF-β and IgA production. IgA cross-reacted with T. spiralis antigen and chitosan. It was found that chitosan treatment attracted immune cells with low activity, which resulted in the number of nematodes increasing. The glucosamine and N-acetyl-D-glucosamine residues were recognized by wheat germ agglutinin (WGA) lectin and therefore any biodegradable chitosan units may actively downregulate the immune response to the parasite. The findings are relevant for both people and animals treated with chitosan preparations. Full article
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3278 KiB  
Article
Synthesis, Characterization and Biological Activities of Biopolymeric Schiff Bases Prepared with Chitosan and Salicylaldehydes and Their Pd(II) and Pt(II) Complexes
by Hellen Franciane Gonçalves Barbosa, Maha Attjioui, Ana Paula Garcia Ferreira, Edward Ralph Dockal, Nour Eddine El Gueddari, Bruno M. Moerschbacher and Éder Tadeu Gomes Cavalheiro
Molecules 2017, 22(11), 1987; https://doi.org/10.3390/molecules22111987 - 16 Nov 2017
Cited by 35 | Viewed by 7427
Abstract
In an attempt to enhance chitosan biological activities, biopolymeric Schiff bases of chitosan and different salicylaldehydes and their palladium(II) and platinum(II) complexes were synthesized and tested. The chemical structures of these derivatives were characterized using 1H-NMR, FTIR spectroscopy and XPRD. Thermal analysis [...] Read more.
In an attempt to enhance chitosan biological activities, biopolymeric Schiff bases of chitosan and different salicylaldehydes and their palladium(II) and platinum(II) complexes were synthesized and tested. The chemical structures of these derivatives were characterized using 1H-NMR, FTIR spectroscopy and XPRD. Thermal analysis was done through TGA/DTG-DTA. Electronic absorption spectra and surface morphologies were analyzed by SEM-EDAX. Chitosan and its derivatives were evaluated for their in vitro antimicrobial activity against two common bacterial and fungal plant pathogens Pseudomonas syringae pv. tomato and Fusarium graminearum, respectively, and for their antitumor activity against a human breast cancer cell line (MCF-7). It was found that, compared to the nonmodified chitosan, chitosan modified with Schiff bases and their complexes was highly toxic against the MCF-7 cell line and had antibacterial effects against P. syringea. However, the modified chitosan derivatives had less pronounced antifungal effects against F. graminearum compared to the nonmodified chitosan, suggesting different modes of action. Full article
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1679 KiB  
Article
Development of Gallic Acid-Modified Hydrogels Using Interpenetrating Chitosan Network and Evaluation of Their Antioxidant Activity
by Byungman Kang, Temmy Pegarro Vales, Byoung-Ki Cho, Jong-Ki Kim and Ho-Joong Kim
Molecules 2017, 22(11), 1976; https://doi.org/10.3390/molecules22111976 - 15 Nov 2017
Cited by 43 | Viewed by 9888
Abstract
In this work, antioxidant hydrogels were prepared by the construction of an interpenetrating chitosan network and functionalization with gallic acid. The poly(2-hydroxyethyl methacrylate) p(HEMA)-based hydrogels were first synthesized and subsequently surface-modified with an interpenetrating polymer network (IPN) structure prepared with methacrylamide chitosan via [...] Read more.
In this work, antioxidant hydrogels were prepared by the construction of an interpenetrating chitosan network and functionalization with gallic acid. The poly(2-hydroxyethyl methacrylate) p(HEMA)-based hydrogels were first synthesized and subsequently surface-modified with an interpenetrating polymer network (IPN) structure prepared with methacrylamide chitosan via free radical polymerization. The resulting chitosan-IPN hydrogels were surface-functionalized with gallic acid through an amide coupling reaction, which afforded the antioxidant hydrogels. Notably, gallic-acid-modified hydrogels based on a longer chitosan backbone exhibited superior antioxidant activity than their counterpart with a shorter chitosan moiety; this correlated to the amount of gallic acid attached to the chitosan backbone. Moreover, the surface contact angles of the chitosan-modified hydrogels decreased, indicating that surface functionalization of the hydrogels with chitosan-IPN increased the wettability because of the presence of the hydrophilic chitosan network chain. Our study indicates that chitosan-IPN hydrogels may facilitate the development of applications in biomedical devices and ophthalmic materials. Full article
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552 KiB  
Article
Effects of Chitooligosaccharide Coating Combined with Selected Ionic Polymers on the Stimulation of Ornithogalum saundersiae Growth
by Piotr Salachna, Monika Grzeszczuk and Marcin Soból
Molecules 2017, 22(11), 1903; https://doi.org/10.3390/molecules22111903 - 04 Nov 2017
Cited by 17 | Viewed by 4846
Abstract
Recently, agricultural and horticultural sectors have shown an increased interest in the use of biopolymers and their derivatives as growth biostimulators. So far, coating is a little known method of applying the biostimulators. Our three-year study investigated coating the bulbs of Ornithogalum saundersiae [...] Read more.
Recently, agricultural and horticultural sectors have shown an increased interest in the use of biopolymers and their derivatives as growth biostimulators. So far, coating is a little known method of applying the biostimulators. Our three-year study investigated coating the bulbs of Ornithogalum saundersiae with chitooligosaccharide (COS), sodium alginate, carrageenan, gellan gum and xanthan gum. The coating method was based on the formation of polyelectrolyte complexes. The COS with 48,000 g mol−1 molecular weight was contained by means of controlled free-radical degradation. Biopolymer coatings stimulated plant growth and flowering, total chlorophyll content, total polyphenol content and the levels of nitrogen, phosphorus, potassium and boron. The plants grown from the bulbs coated with COS + gellan gum exhibited the most vigorous growth, were first to flower, showed the highest antioxidant activity (DPPH), and the greatest content of pigments, polyphenols, l-ascorbic acid, potassium, phosphorus, zinc and manganese. These results suggest COS formulated with gellan gum shows promise as a potential biostimulator of plant growth. Full article
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9219 KiB  
Article
Visible Light-Cured Glycol Chitosan Hydrogel Containing a Beta-Cyclodextrin-Curcumin Inclusion Complex Improves Wound Healing In Vivo
by Sun-Jung Yoon, Hoon Hyun, Deok-Won Lee and Dae Hyeok Yang
Molecules 2017, 22(9), 1513; https://doi.org/10.3390/molecules22091513 - 10 Sep 2017
Cited by 44 | Viewed by 8315
Abstract
Scarless wound healing is ideal for patients suffering from soft tissue defects. In this study, we prepared a novel wet dressing (β-CD-ic-CUR/GC) based on the visible light-cured glycol chitosan (GC) hydrogel and inclusion complex between beta-cyclodextrin (β-CD) and curcumin (CUR). We also evaluated [...] Read more.
Scarless wound healing is ideal for patients suffering from soft tissue defects. In this study, we prepared a novel wet dressing (β-CD-ic-CUR/GC) based on the visible light-cured glycol chitosan (GC) hydrogel and inclusion complex between beta-cyclodextrin (β-CD) and curcumin (CUR). We also evaluated its efficacy in the acceleration of wound healing as compared to that of CUR-loaded GC (CUR/GC). The conjugation of glycidyl methacrylate (GM) to GC for photo-curing was confirmed by 1H-NMR measurement, and the photo-cured GC hydrogel was characterized by the analyses of rheology, swelling ratio, SEM and degradation rate. After visible light irradiation, the surface/cross-sectional morphologies and storage (G′)/loss (G′′) moduli revealed the formation of hydrogel with interconnected porosity. The dressing β-CD-ic-CUR/GC exhibited a controlled release of 90% CUR in a sustained manner for 30 days. On the other hand, CUR/GC showed CUR release of 16%. β-CD acted as an excipient in improving the water-solubility of CUR and affected the release behavior of CUR. The in vivo animal tests including measurement of the remaining unhealed wound area and histological analyses showed that β-CD-ic-CUR/GC may have potential as a wet dressing agent to enhance soft tissue recovery in open fractures. Full article
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2943 KiB  
Article
Preparation and Characterization of Novel Cationic Chitosan Derivatives Bearing Quaternary Ammonium and Phosphonium Salts and Assessment of Their Antifungal Properties
by Wenqiang Tan, Qing Li, Fang Dong, Qiuhong Chen and Zhanyong Guo
Molecules 2017, 22(9), 1438; https://doi.org/10.3390/molecules22091438 - 31 Aug 2017
Cited by 37 | Viewed by 6868
Abstract
Chitosan is an abundant and renewable polysaccharide, its derivatives exhibit attractive bioactivities and the wide applications in various biomedical fields. In this paper, two novel cationic chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized via trimethylation, chloride acetylation, and quaternization with [...] Read more.
Chitosan is an abundant and renewable polysaccharide, its derivatives exhibit attractive bioactivities and the wide applications in various biomedical fields. In this paper, two novel cationic chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized via trimethylation, chloride acetylation, and quaternization with tricyclohexylphosphine and triphenylphosphine. The structures and properties of synthesized products in the reactions were characterized by FTIR spectroscopy, 1H-NMR, 31P-NMR, elemental and thermogravimetric analysis. The antifungal activities of chitosan derivatives against four kinds of phytopathogens, including Phomopsis asparagi, Watermelon fusarium, Colletotrichum lagenarium, and Fusarium oxysporum were tested using the radial growth assay in vitro. The results revealed that the synthesized cationic chitosan derivatives showed significantly improved antifungal efficiency compared to chitosan. It was reasonably suggested that quaternary phosphonium groups enabled the obviously stronger antifungal activity of the synthesized chitosans. Especially, the triphenylphosphonium-functionalized chitosan derivative inhibited the growth of Phomopsis asparagi most effectively, with inhibitory indices of about 80% at 0.5 mg/mL. Moreover, the data demonstrated that the substituted groups with stronger electron-withdrawing ability relatively possessed greater antifungal activity. The results suggest the possibility that cationic chitosan derivatives bearing quaternary phosphonium salts could be effectively employed as novel antifungal biomaterials for application in the field of agriculture. Full article
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3583 KiB  
Article
Synthesis, Characterization and In Vitro Evaluation of a Novel Glycol Chitosan-EDTA Conjugate to Inhibit Aminopeptidase-Mediated Degradation of Thymopoietin Oligopeptides
by Jiao Feng, Yan Chen, Feng Li, Lili Cui, Nianqiu Shi, Wei Kong and Yong Zhang
Molecules 2017, 22(8), 1253; https://doi.org/10.3390/molecules22081253 - 26 Jul 2017
Cited by 14 | Viewed by 5557
Abstract
In this study, a novel conjugate consisting of glycol chitosan (GCS) and ethylene diamine tetraacetic acid (EDTA) was synthesized and characterized in terms of conjugation and heavy metal ion chelating capacity. Moreover, its potential application as a metalloenzyme inhibitor was evaluated with three [...] Read more.
In this study, a novel conjugate consisting of glycol chitosan (GCS) and ethylene diamine tetraacetic acid (EDTA) was synthesized and characterized in terms of conjugation and heavy metal ion chelating capacity. Moreover, its potential application as a metalloenzyme inhibitor was evaluated with three thymopoietin oligopeptides in the presence of leucine aminopeptidase. The results from FTIR and NMR spectra revealed that the covalent attachment of EDTA to GCS was achieved by the formation of amide bonds between the carboxylic acid group of EDTA and amino groups of GCS. The conjugated EDTA lost part of its chelating capacity to cobalt ions compared with free EDTA as evidenced by the results of cobalt ion chelation-mediated fluorescence recovery of calcein. However, further investigation confirmed that GCS-EDTA at low concentrations significantly inhibited leucine aminopeptidase-mediated degradation of all thymopoietin oligopeptides. Full article
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681 KiB  
Article
Use of Chitosan-PVA Hydrogels with Copper Nanoparticles to Improve the Growth of Grafted Watermelon
by Homero González Gómez, Francisca Ramírez Godina, Hortensia Ortega Ortiz, Adalberto Benavides Mendoza, Valentín Robledo Torres and Marcelino Cabrera De la Fuente
Molecules 2017, 22(7), 1031; https://doi.org/10.3390/molecules22071031 - 22 Jun 2017
Cited by 32 | Viewed by 5826
Abstract
Modern agriculture requires alternative practices that improve crop growth without negatively affecting the environment, as resources such as water and arable land grow scarcer while the human population continues to increase. Grafting is a cultivation technique that allows the plant to be more [...] Read more.
Modern agriculture requires alternative practices that improve crop growth without negatively affecting the environment, as resources such as water and arable land grow scarcer while the human population continues to increase. Grafting is a cultivation technique that allows the plant to be more efficient in its utilization of water and nutrients, while nanoscale material engineering provides the opportunity to use much smaller quantities of consumables compared to conventional systems but with similar or superior effects. On those grounds, we evaluated the effects of chitosan-polyvinyl alcohol hydrogel with absorbed copper nanoparticles (Cs-PVA-nCu) on leaf morphology and plant growth when applied to grafted watermelon cultivar ‘Jubilee’ plants. Stomatal density (SD), stomatal index (SI), stoma length (SL), and width (SW) were evaluated. The primary stem and root length, the stem diameter, specific leaf area, and fresh and dry weights were also recorded. Our results demonstrate that grafting induces modifications to leaf micromorphology that favorably affect plant growth, with grafted plants showing better vegetative growth in spite of their lower SD and SI values. Application of Cs-PVA-nCu was found to increase stoma width, primary stem length, and root length by 7%, 8% and 14%, respectively. These techniques modestly improve plant development and growth. Full article
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1185 KiB  
Article
Cu Nanoparticles in Hydrogels of Chitosan-PVA Affects the Characteristics of Post-Harvest and Bioactive Compounds of Jalapeño Pepper
by Zeus H. Pinedo-Guerrero, Alma Delia Hernández-Fuentes, Hortensia Ortega-Ortiz, Adalberto Benavides-Mendoza, Gregorio Cadenas-Pliego and And Antonio Juárez-Maldonado
Molecules 2017, 22(6), 926; https://doi.org/10.3390/molecules22060926 - 02 Jun 2017
Cited by 48 | Viewed by 5538
Abstract
Peppers are consumed all over the world due to the flavor, aroma, and color that they add to food. Additionally, they play a role in human health, as they contain a high concentration of bioactive compounds and antioxidants. The treatments used were an [...] Read more.
Peppers are consumed all over the world due to the flavor, aroma, and color that they add to food. Additionally, they play a role in human health, as they contain a high concentration of bioactive compounds and antioxidants. The treatments used were an absolute control, Cs-PVA, and four treatments with 0.02, 0.2, 2, and 10 mg (nCu) g−1 (Cs-PVA). The application of Cu nanoparticles in chitosan-PVA hydrogels increases the content of capsaicin by up to 51% compared to the control. This application also increases the content of antioxidants ABTS [2,2′-azino-bis (3-ethylbenzothiazolin-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl), total phenols and flavonoids (4%, 6.6%, 5.9%, and 12.7%, respectively) in jalapeño pepper fruits stored for 15 days at room temperature; under refrigeration, it increases DPPH antioxidants, total phenols, and flavonoids (23.9%, 1.54%, and 17.2%, respectively). The application of Cu nanoparticles in chitosan-PVA hydrogels, even when applied to the substrate, not only has an effect on the development of the jalapeño pepper crop, but also modifies the post-harvest characteristics of the jalapeño pepper fruits. Full article
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Review

Jump to: Research

19 pages, 12318 KiB  
Review
Chemical Modification of Chitosan for Efficient Vaccine Delivery
by Lei Xing, Ya-Tong Fan, Tian-Jiao Zhou, Jia-Hui Gong, Lian-Hua Cui, Ki-Hyun Cho, Yun-Jaie Choi, Hu-Lin Jiang and Chong-Su Cho
Molecules 2018, 23(2), 229; https://doi.org/10.3390/molecules23020229 - 25 Jan 2018
Cited by 68 | Viewed by 8196
Abstract
Chitosan, which exhibits good biocompatibility, safety, microbial degradation and other excellent performances, has found application in all walks of life. In the field of medicine, usage of chitosan for the delivery of vaccine is favored by a wide range of researchers. However, due [...] Read more.
Chitosan, which exhibits good biocompatibility, safety, microbial degradation and other excellent performances, has found application in all walks of life. In the field of medicine, usage of chitosan for the delivery of vaccine is favored by a wide range of researchers. However, due to its own natural limitations, its application has been constrained to the beginning of study. In order to improve the applicability for vaccine delivery, researchers have carried out various chemical modifications of chitosan. This review summarizes a variety of modification methods and applications of chitosan and its derivatives in the field of vaccine delivery. Full article
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1620 KiB  
Review
Versatile Chemical Derivatizations to Design Glycol Chitosan-Based Drug Carriers
by Sung Eun Kim, Hak-Jun Kim, Jin-Kyu Rhee and Kyeongsoon Park
Molecules 2017, 22(10), 1662; https://doi.org/10.3390/molecules22101662 - 05 Oct 2017
Cited by 12 | Viewed by 7560
Abstract
Glycol chitosan (GC) and its derivatives have been extensively investigated as safe and effective drug delivery carriers because of their unique physiochemical and biological properties. The reactive functional groups such as the amine and hydroxyl groups on the GC backbone allow for easy [...] Read more.
Glycol chitosan (GC) and its derivatives have been extensively investigated as safe and effective drug delivery carriers because of their unique physiochemical and biological properties. The reactive functional groups such as the amine and hydroxyl groups on the GC backbone allow for easy chemical modification with various chemical compounds (e.g., hydrophobic molecules, crosslinkers, and acid-sensitive and labile molecules), and the versatility in chemical modifications enables production of a wide range of GC-based drug carriers. This review summarizes the versatile chemical modification methods that can be used to design GC-based drug carriers and describes their recent applications in disease therapy. Full article
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