Polysaccharide Chitosan Research Articles

Preparation, characterization, and antifungal evaluation of a new type of aminourea chitooligosaccharide derivatives

Phytopathogenic fungi cause heavy negative impact on the agricultural economy, but most existing fungicides are toxic and pose a threat to both human health and environments. A green and efficient fungicide is urgently needed. Chitooligosaccharides (COSs), the degradation products of natural polysaccharide chitosan, are nontoxic and biodegradable antifungal substances. In this study, a novel type of aminourea chitooligosaccharide derivatives (AUCOS) was synthesized by successively grafting a hydrazine group and an amine-carbonyl group onto a chitooligosaccharide backbone to enhance the antifungal capability of COSs. The structures of the target compounds were identified by FTIR, 1 H NMR, and 13 C NMR, and the degree of substitution of each product was calculated from the results of the elemental analysis. The antifungal activities of the prepared chitooligosaccharide derivatives against Fusarium solani, Verticillium albo-atrum and Phytophthora capsici were tested in vitro. The AUCOSs had better inhibitory efficiencies against the three plant pathogen fungi than that of chitooligosaccharide, of which aminourea chitooligosaccharide 2 (AUCOS2) was the most promising antifungal compound, whose highest inhibition rates were 60.12%, 82.95%, and 85.23% against F. solani, V. albo-atrum and P. capsici, respectively. The synthesized derivatives have good application prospects in crop protection and deserve further research.

DNA from Plant leaf Extracts: A Review for Emerging and Promising Novel Green Corrosion Inhibitors

With growing global awareness and concern for environmental protection through the use of less hazardous and environmentally-friendly extracts of plant origin, there has been a plethora of green corrosion inhibitors research with far reaching contributions to the science of corrosion prevention and control. Attention has increasingly turned towards green corrosion inhibitors, compounds of natural origin with anti-oxidant activity towards metals and their alloys. Green inhibitors have been investigated for their corrosion and adsorption properties with good results. The findings from these research works provide evidence of the adsorption behavior of green inhibitors which was confirmed by the adsorption isotherms that were proposed. Adsorption is the first step of any surface reaction and since corrosion is a surface phenomenon the effectiveness of green corrosion inhibitors is related to their ability to adsorb on metal surfaces. This review proposes the potential of plant dna as an emerging and promising novel inhibitor for mild steel. It begins with a list of plants that have been used in studies to determine corrosion inhibition properties and moves on to establish the adsorption behavior of bio macromolecules; protein, polysaccharides (chitosan) and dna. It reviews studies and investigation of dna interaction and adsorption on inorganic surfaces before focusing on the use of salmon (fish) sperm dna and calf thymus gland dna as green corrosion inhibitors for mild steel. It concludes that plant dna is a promising candidate for green corrosion inhibitor given the similarity between the plant and animal dna structure and function, and the fact that the use of plant is more environmentally sustainable than animal-based product.

Green chemistry based in-situ synthesis of silver nanoparticles for multifunctional finishing of chitosan polysaccharide modified cellulosic textile substrate

Herein, a highly efficient multifunctional cotton fabric was developed based on a greener approach involving one step in-situ generation of silver nanoparticles (AgNPs) onto chitosan coated cotton (CS-cotton) by employing peanut waste shell extract (PSE) as an eco-friendly reducing agent. Major characteristics of the so prepared in-situ AgNPs@ chitosan-cotton viz size distribution of the particles, surface morphology, binding interaction were analysed by TEM-DLS, SEM, EDX-mapping, and FT-IR techniques. Colour spectrometry was used to measure colour parameters in terms of CIELa*b* values in order to realize the dyeing properties of silver nanoparticles onto chitosan coated cotton. The AgNPs deposited finished cotton samples were evaluated for antioxidant activity using 2, 2′-diphenyl-1-picrylhydrazyl radical (DPPH) assay, and antimicrobial tests were carried out using colony counting method against E. coli and S. aureus pathogens. Based on the obtained data, it was concluded that in-situ synthesis of AgNPs using peanut shell extract biomolecules produce cellulosic fabric with beautiful pale to deep yellowish hues, good antioxidant and excellent antibacterial properties. The tentative mechanism of AgNPs formation onto chitosan coated cotton was also reported.

The preparation of graphene ink from the exfoliation of graphite in pullulan, chitosan and alginate for strain-sensitive paper

A sonication of graphite in polysaccharide (pullulan, chitosan and alginate) is one of the viable methods for the preparation of few-layer graphene. However, the effect of these adsorbed polysaccharides on the electrical performance of the produced graphene so far is not yet clear. In order to investigate the present effect of pullulan, chitosan and alginate on the electrical characteristic of resulted graphene, we have produced few-layer graphene using bath sonication of graphite in pullulan, chitosan and alginate medium for the application as electrical conductive ink in strain-sensitive. Data from the TEM reveals the appearance of folded few-layer graphene flakes after sonication for 150 min while the XPS data shows that the chitosan-based graphene possesses the highest carbon-oxygen ratio of 7.2 as compared to that of the pullulan and alginate-based graphene. By subjecting the produced graphene as the ink for paper-based strain sensor, we have discovered that the chitosan-graphene has the best resistivity value (1.66 × 10-3 Ω⋅cm) and demonstrate the highest sensitivity towards strain (GF: 18.6). This result interestingly implies the potential of the reported chitosan-based conductive ink as a strain-sensitive material for future food packaging.

Assessment of Oligo-Chitosan Biocompatibility toward Human Spermatozoa.

The many interesting properties of chitosan polysaccharides have prompted their extensive use as biomaterial building blocks, for instance as antimicrobial coatings, tissue engineering scaffolds, and drug delivery vehicles. The translation of these chitosan-based systems to the clinic still requires a deeper understanding of their safety profiles. For instance, the widespread claim that chitosans are spermicidal is supported by little to no data. Herein, we thoroughly investigate whether chitosan oligomer (CO) molecules can impact the functional and structural features of human spermatozoa. By using a large number of primary sperm cell samples and by isolating the effect of chitosan from the effect of sperm dissolution buffer, we provide the first realistic and complete picture of the effect of chitosans on sperms. We found that CO binds to cell surfaces or/and is internalized by cells and affected the average path velocity of the spermatozoa, in a dose-dependent manner. However, CO did not affect the progressive motility, motility, or sperm morphology, nor did it cause loss of plasma membrane integrity, reactive oxygen species production, or DNA damage. A decrease in spermatozoa adenosine triphosphate levels, which was especially significant at higher CO concentrations, points to possible interference of CO with mitochondrial functions or the glycolysis processes. With this first complete and in-depth look at the spermicidal activities of chitosans, we complement the complex picture of the safety profile of chitosans and inform on further use of chitosans in biomedical applications.

Oral Pharmacokinetics of a Chitosan-Based Nano- Drug Delivery System of Interferon Alpha.

Interferon alpha (IFNα) is a protein drug used to treat viral infections and cancer diseases. Due to its poor stability in the gastrointestinal tract, only parenteral administration ensures bioavailability, which is associated with severe side effects. We hypothesized that the nanoencapsulation of IFNα within nanoparticles of the mucoadhesive polysaccharide chitosan would improve the oral bioavailability of this drug. In this work, we produced IFNα-loaded chitosan nanoparticles by the ionotropic gelation method. Their hydrodynamic diameter, polydispersity index and concentration were characterized by dynamic light scattering and nanoparticle tracking analysis. After confirming their good cell compatibility in Caco-2 and WISH cells, the permeability of unmodified and poly(ethylene glycol) (PEG)-modified (PEGylated) nanoparticles was measured in monoculture (Caco-2) and co-culture (Caco-2/HT29-MTX) cell monolayers. Results indicated that the nanoparticles cross the intestinal epithelium mainly by the paracellular route. Finally, the study of the oral pharmacokinetics of nanoencapsulated IFNα in BalbC mice revealed two maxima and area-under-the-curve of 56.9 pg*h/mL.

A chitosan-assisted co-assembly synthetic route to low-shrinkage Al2O3–SiO2 aerogel via ambient pressure drying

Abstract A straightforward chitosan/inorganic salts co-assembly sol-gel strategy was explored to modify the alumina gel at a molecular level, based on polymerization and covalent interaction of chitosan polysaccharide. Serving as a 3D soft template, the chitosan could chelate with hydrolyzed aluminum species to form an enhanced interdigitated network. A monolithic chitosan/alumina-silica (CAS) composite aerogel with fairly low shrinkage of about 17% was contrived through a follow-up surface modification by tetraethoxysilane and a simple ambient pressure drying (APD) process. It was found that the morphology and nanostructure of the aerogel could be readily tuned by changing the amount of acetic acid during the sol-gel process. Compared with the conventional alumina-silica aerogel, CAS aerogel exhibited analogous high temperature thermal stability and refined microstructure, making it as a favorable candidate in adsorption and catalysis arenas at higher temperature. Moreover, the monolithic CAS composite aerogel is expected to be beneficial in modifying membranes for baromembrane separation due to its high porosity as well as hydrophilic property.

Chitosan functionalized iron nanosheet for enhanced removal of As(III) and Sb(III): Synergistic effect and mechanism

Neutral trivalent arsenic (As(III)) and antimony (Sb(III)) species are more toxic and harder to remove from wastewater environment than their pentavalent counterparts. Herein, a natural polysaccharide chitosan (CS) functionalized iron nanosheet using an in-situ doping method was designed, aiming to attract As(III) and Sb(III) from aqueous solution. The surface area of the optimum sample was 111.8 cm2/g, a good dispersion of the iron nanocomposite was observed by the TEM and element mapping characterization. In the batch adsorption experiment the factors of doping contents of CS and solution properties (pH, co-existing anions and humic acid) were studied systematically. The result showed that 0.5 wt% CS functionalized iron nanosheet had higher removal capacity, affinity, selectivity and reusability for Sb(III) than As(III). The optimum adsorption were achieved at the adsorbent dosage of 0.4 g/L at a wide pH values, and the maximum adsorption capacity were 108.6 and 138.8 mg/g for As(III) and Sb(III) calculated from Langmuir non-linear fitting, respectively. Both As(III) and Sb(III) removal were independent on pH values, indicating electrostatic attraction was not the dominate removal mechanism. The detailed removal mechanism was confirmed by a synergetic interaction of As-Fe/Sb-Fe complexes and hydrogen bonding using the combined characterization of FTIR and XPS spectra. This study demonstrated that the CS functionalized iron nanosheet with the properties of environmental friendly, low-cost and facile preparation could have potential applications in water purification.

Polymers and Polymer Nanocomposites for Cancer Therapy

Synthetic polymers, biopolymers, and their nanocomposites are being studied, and some of them are already used in different medical areas. Among the synthetic ones that can be mentioned are polyolefins, fluorinated polymers, polyesters, silicones, and others. Biopolymers such as polysaccharides (chitosan, hyaluronic acid, starch, cellulose, alginates) and proteins (silk, fibroin) have also become widely used and investigated for applications in medicine. Besides synthetic polymers and biopolymers, their nanocomposites, which are hybrids formed by a macromolecular matrix and a nanofiller (mineral or organic), have attracted great attention in the last decades in medicine and in other fields due to their outstanding properties. This review covers studies done recently using the polymers, biopolymers, nanocomposites, polymer micelles, nanomicelles, polymer hydrogels, nanogels, polymersomes, and liposomes used in medicine as drugs or drug carriers for cancer therapy and underlines their responses to internal and external stimuli able to make them more active and efficient. They are able to replace conventional cancer drug carriers, with better results.

Using cellulose nanofibers to reinforce polysaccharide films: Blending vs layer-by-layer casting

Based on the electrostatic interaction mechanism, cellulose nanofiber (CNF) was utilized as reinforcing additives to fabricate polysaccharide films (alginate (Alg) or chitosan (CH)) by two methods: blending and layer-by-layer (LbL). Results showed that the addition of CNF led to higher tensile strength for all films than those without CNF addition, except for the blending CH film due to CNF agglomeration. The highest TS reached 140 MPa for the blending Alg film at 7 wt% CNF. Moreover, all CNF-reinforced films generally had lower water vapor permeability. The addition of CNF aggravated the opacity of all films, especially for the blending ones. Microstructure indicated that CNF were well dispersed in Alg-based films while aggregates were evident in the blending CH films. Interactions between CNF and Alg (or CH) and their relations on film performance were supported by FTIR and DSC of the resultant films, zeta-potential and turbidity of the film-forming solutions.

Diets with and without edible cricket support a similar level of diversity in the gut microbiome of dogs.

The gut microbiome plays an important role in the health of dogs. Both beneficial microbes and overall diversity can be modulated by diet. Fermentable sources of fiber in particular often increase the abundance of beneficial microbes. Banded crickets (Gryllodes sigillatus) contain the fermentable polysaccharides chitin and chitosan. In addition, crickets are an environmentally sustainable protein source. Considering crickets as a potential source of both novel protein and novel fiber for dogs, four diets ranging from 0% to 24% cricket content were fed to determine their effects on healthy dogs’ (n = 32) gut microbiomes. Fecal samples were collected serially at 0, 14, and 29 days, and processed using high-throughput sequencing of 16S rRNA gene PCR amplicons. Microbiomes were generally very similar across all diets at both the phylum and genus level, and alpha and beta diversities did not differ between the various diets at 29 days. A total of 12 ASVs (amplicon sequence variants) from nine genera significantly changed in abundance following the addition of cricket, often in a dose-response fashion with increasing amounts of cricket. A net increase was observed in Catenibacterium, Lachnospiraceae [Ruminococcus], and Faecalitalea, whereas Bacteroides, Faecalibacterium, Lachnospiracaeae NK4A136 group and others decreased in abundance. Similar changes in Catenibacterium and Bacteroides have been associated with gut health benefits in other studies. However, the total magnitude of all changes was small and only a few specific taxa changed in abundance. Overall, we found that diets containing cricket supported the same level of gut microbiome diversity as a standard healthy balanced diet. These results support crickets as a potential healthy, novel food ingredient for dogs.

Biodegradable Polymer Materials Based on Polylactide

Under conditions of shear deformations in a Brabender-type mixer by solid-phase mixing, polylactide compositions with different polysaccharides (starch, microcrystalline cellulose, ethylcellulose, and chitosan) are produced using. To improve the elasticity of the compositions, poly(ethylene glycol) is introduced as a plasticizer. It is shown that the mechanical characteristics, water absorption, and biodegradability of the compositions depend on the component ratio and nature of the polysaccharide used. A biodegradation mechanism has been proposed based on data from scanning electron microscopy and IR-spectroscopy.

Physico-chemistry of a successful micro-reactor: Random coils of chitosan backbones used to synthesize size-controlled silver nanoparticles

The synthetic system to produce silver nanoparticles (AgNP) based on the thermally activated reduction of aqueous silver ions by chitosan (CS) polysaccharide is investigated to unravel the physicochemical processes controlling AgNP nucleation and growth. An anomalous preeminence of AgNP nucleation over growth is found for conditions under which the opposite trend is obeyed for AgNP synthesized from soluble precursors in homogeneous media. The behavior is modeled assuming the formation of a tridimensional supramolecular structure from silver ions / CS´s amino groups coordination complexes, driving the crosslinking within polymer folding and aggregation in shaping random coils. These structures become reactive precursor structures, that behave as microreactors during thermal treatment, and AgNP size are modulated by controlling the amino groups to silver ion ratio. Stabilized AgNP of high quality are easily produced from an environment-friendly synthetic system, which requires low cost reagents and demands simple and safe laboratory procedures.

Redox-initiated diffusion-limited aggregation in biopolymer

Fractal patterns have been obtained in a polysaccharide (chitosan biopolymer) containing salt and an active metal wire. The amino groups in chitosan chelate with silver ions and form a cationic complex with the silver nitrate (AgNO3). Presence of the copper wire in the chitosan–AgNO3 system leads to an exothermic redox reaction which creates an anisotropy in the system affecting the growth mechanism. Initial movement of the ions is governed by the potential difference between the redox species/couple (Cu and Ag) and the energy released in terms of heat enhances the mobility of the mobile fractal forming species. This release in energy is reflected in the rise in temperature of the system by 4° to 5 °C. Initially, dense patterns form around the corners of the metal wire, which in time change to diffusion-limited aggregates as the redox reaction rate changes due to the depletion of the active metal wire’s ions. The fractal forming species (Ag) has been confirmed by x-ray diffraction, energy dispersive x-ray analysis and scanning electron microscopy. The fractal dimension determined by the box-counting method confirms the formation of a dense branched morphology at the corners of the metal wire and diffusion-limited aggregation away from the corners. The aggregation process and resulting pattern in the present experimental system evolves due to the varying spatial and temporal anisotropy existing within the system.

Categories and biomanufacturing methods of glucosamine.

Glucosamine (GlcN) is an amine sugar, in which a hydroxyl group of glucose is replaced with an amino group. It is an important part of the polysaccharides chitin and chitosan and is highly hydrophilic. It is also an important compound required for the formation of cartilage cells and represents one of the elementary units of the cartilage matrix and joint fluid. GlcN has been widely used in food, cosmetics, health care, and pharmaceutical industries. This paper fully addresses the categories and biomanufacturing methods of GlcN, including its production by fermentation with wild-type as well as engineered microorganisms and enzymatic catalysis with a series of chitinolytic enzymes. However, GlcN is usually produced from glucose by fermentation in a coupled manner with N-acetylglucosamine (GlcNAc). Enzymatic catalysis is thus a specific pathway for production of GlcN where chitin can be directly hydrolyzed to GlcN. In industry, GlcN produced with fungal mycelium as raw materials (plant GlcN) is thought as a high-end product because of vegetarian and non-transgenosis. In our opinion, more studies should be performed in order to develop a competitive enzymatic pathway using Aspergillus niger mycelium for the preparation of high-end GlcN.

The Influence of Polysaccharide Coating on the Physicochemical Parameters and Cytotoxicity of Silica Nanoparticles for Hydrophilic Biomolecules Delivery.

The present work reports the effect of polysaccharides (chitosan and sodium alginate) on silica nanoparticles (SiNP) for hydrophilic molecules delivery taking insulin as model drug. The influence of tetraethyl orthosilicate (TEOS) and homogenization speed on SiNP properties was assessed by a 22 factorial design achieving as optimal parameters: 0.43 mol/L of TEOS and homogenization speed of 5000 rpm. SiNP mean particle size (Z-Ave) was of 256.6 nm and polydispersity index (PI) of 0.218. SiNP coated with chitosan (SiNP-CH) or sodium alginate (SiNP-SA) increased insulin association efficacy; reaching 84.6% (SiNP-SA) and 90.8% (SiNP-CH). However, coated SiNP released 50–60% of the peptide during the first 45 min at acidic environment, while uncoated SiNP only released ~30%. Similar results were obtained at pH 6.8. The low Akaike’s (AIC) values indicated that drug release followed Peppas model for SiNP-SA and second order for uncoated SiNP and SiNP-CH (pH 2.0). At pH 6.8, the best fitting was Boltzmann for Ins-SiNP. However, SiNP-CH and SiNP-SA showed a first-order behavior. Cytotoxicity of nanoparticles, assessed in Caco-2 and HepG2 cells, showed that 100 to 500 µg/mL SiNP-CH and SiNP-SA slightly decreased cell viability, comparing with SiNP. In conclusion, coating SiNP with selected polysaccharides influenced the nanoparticles physicochemical properties, the insulin release, and the effect of these nanoparticles on cell viability.

Screening of different polysaccharides in a composite film based on Eudragit RS for subsequent use as a coating for delivery of 5-ASA to colon.

This study aims at identifying the more suitable polysaccharide in a composite film based on Eudragit RS for 5-ASA delivery to the colon. Different polysaccharides (pectin, chitosan, guar, inulin, and dextran) were examined. The mechanical properties, swelling index, loss of film mass and permeability of films to 5-ASA were recorded at simulating gastric (SGF), intestinal (SIF) and colonic fluids (SCF). Films containing inulin or dextran were more flexible and showed better mechanical properties. Films containing chitosan, pectin or guar exhibited extensive swelling in SGF and SIF. Loss of film mass and drug permeation was more pronounced in SCF than SIF for all samples indicating their sensitivity to colonic bacteria. However, films containing inulin or dextran showed minimum swelling index in SGF and SIF and the highest ratio of permeability in SCF to SIF. Accordingly, inulin and dextran are suggested as appropriate polysaccharides in a film based on Eudragit RS for colon delivery of 5-ASA.

Chitosan-bioglass coatings on partially nanostructured anodized Ti-6Al-4V alloy for biomedical applications

In this investigation we report the fabrication of composite coatings with silver nanoparticles (AgNPs), bioactive 45S5 Bioglass® (45S5 BG) and the polysaccharide chitosan (CTS) by voltage-pulsed (VP) and voltage-constant (VC) electrophoretic deposition (EPD) on Ti-6Al-4V anodized surfaces. AgNPs were synthesized by chemical reduction and subsequently added to a CTS-45S5 BG suspension. Electrochemical anodization of the alloy produced titanium dioxide nanotubes (TiO2 NTBs) which offered nanoarchitecture on the substrate, promoting the apatite growth and generating a suitable microenvironment for macrophages. The different microstructures of the coatings produced with VP and VC affected the lactate dehydrogenase (LDH) and nitric oxide (NO) production from murine macrophages cultured on the coatings. These results initially help assess the biocoating's microstructure and chemical composition as a suitable implant.

C60 fullerene loaded hydroxyapatite-chitosan beads as a promising system for prolonged drug release

Bioactive composite material in the form of beads, based on natural polysaccharide Chitosan (CS), hydroxyapatite (HA), and C60 fullerene (C60), was synthesized under influence of microwave irradiation (MW). The bead is a 3D matrix consisting of CS macromolecules cross-linked with sodium tripolyphosphate with HA and C60 particles immobilized in its structure. XRD and FTIR data confirmed the formation of calcium deficient carbonate substituted HA with needle-shaped nanocrystallites of about 80 nm. MW does not influence CS structure. C60 enhances the beads shape stability. HPLC studies suggest the (up to 18 days) prolonged release of hydrophobic Anaesthesinum from C60-containing composites. Changing the C60 content allows adjusting the drug release time. The presence of CS and C60 provides the Anaestesinum release profile, according to the calculated correlation coefficient (r = 0.99), close to the zero order kinetic release profile. The inhibition zone test (ZOI) shows the antimicrobial activity of the composites containing 0.004 mg/ml C60 against S. aureus ATCC 25923 and E. coli ATCC 25922 (ZOI 16 ± 1 and 10 ± 2 mm, respectively). Cell viability test indicates no toxicity of 0.3 and 0.15 mg/ml C60-containing composites.

Hybrid plasma chemical reactors for bio-polymers processing

Design of a hybrid plasma-chemical reactor in which strongly non-equilibrium low-temperature plasma is generated by joint action of a continuous electron beam and RF-gas discharge on gaseous media at moderate pressures (0.1–10 Torr) is described. Several versions of the reactor in a co-axial configuration were tested on the special experimental setup. Main characteristics of the reaction zone were studied as functions of electron beam and gas discharge parameters, plasma-generating media properties and peculiarities of the working process features. Temperature regimes of the materials processing were reliably controlled by the electron beam parameters. The reactor was applied to thin films and dispersed powders of natural polysaccharides (chitosan) and biomaterials (wood) processing to produce valuable low-molecular and bioactive compounds. In hybrid plasma of oxygen, the active particles responsible for the materials modification effects are atomic oxygen, ozone and singlet oxygen. Special software simulating the reactor operation and material treatment processes in plasmas of oxygen was developed and experimentally verified.