Displaying publications 1 - 20 of 195 in total

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  1. Subramaniam S, Foo KY, Md Yusof EN, Jawad AH, Wilson LD, Sabar S
    Int J Biol Macromol, 2021 Dec 15;193(Pt B):1716-1726.
    PMID: 34742842 DOI: 10.1016/j.ijbiomac.2021.11.009
    Phosphorylated chitosan (P-CS) was successfully synthesized using a facile experimental setup of hydrothermal method that was applied to the adsorption of anionic Acid Red 88 (AR88) from aqueous media. The adsorption process obeyed the pseudo-second-order (PSO) kinetic model. In contrast, the adsorption isotherm conformed to the Langmuir model, with the maximum adsorption capacity (qm = 230 mg g-1) at 303 K. Both external and intraparticle diffusion strongly influenced the rate of adsorption. The insights from this study reveal that P-CS could be easily prepared and regenerated for reusability applications. The adsorption mechanism and intermolecular interaction between P-CS and AR 88 were investigated using Fourier transform infrared (FTIR) spectroscopy and calculations via Density Functional Theory (DFT). The key modes of adsorption for the P-CS/AR 88 system are driven by electrostatic attractions, H-bonding, and n-π interactions. The findings herein reveal that P-CS is a promising adsorbent for the removal of anionic dyes such as AR88 or similar pollutants from water.
    Matched MeSH terms: Chitosan/chemistry*
  2. Khan MUA, Haider S, Raza MA, Shah SA, Razak SIA, Kadir MRA, et al.
    Int J Biol Macromol, 2021 Dec 01;192:820-831.
    PMID: 34648803 DOI: 10.1016/j.ijbiomac.2021.10.033
    Carbohydrate polymers are biological macromolecules that have sparked a lot of interest in wound healing due to their outstanding antibacterial properties and sustained drug release. Arabinoxylan (ARX), Chitosan (CS), and reduced graphene oxide (rGO) sheets were combined and crosslinked using tetraethyl orthosilicate (TEOS) as a crosslinker to fabricate composite hydrogels and assess their potential in wound dressing for skin wound healing. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and biological assays were used to evaluate the composite hydrogels. FTIR validated the effective fabrication of the composite hydrogels. The rough morphologies of the composite hydrogels were revealed by SEM and AFM (as evident from the Ra values). ATC-4 was discovered to have the roughest surface. TEM revealed strong homogeneous anchoring of the rGO to the polymer matrix. However, with higher amount of rGO agglomeration was detected. The % swelling at various pHs (1-13) revealed that the hydrogels were pH-sensitive. The controlled release profile for the antibacterial drug (Silver sulfadiazine) evaluated at various pH values (4.5, 6.8, and 7.4) in PBS solution and 37 °C using the Franz diffusion method revealed maximal drug release at pH 7.4 and 37 °C. The antibacterial efficacy of the composite hydrogels against pathogens that cause serious skin diseases varied. The MC3T3-E1 cell adhered, proliferated, and differentiated well on the composite hydrogels. MC3T3-E1 cell also illustrated excellent viability (91%) and proper cylindrical morphologies on the composite hydrogels. Hence, the composite hydrogels based on ARX, CS, and rGO are promising biomaterials for treating and caring for skin wounds.
    Matched MeSH terms: Chitosan/chemistry*
  3. Sadiq AC, Olasupo A, Ngah WSW, Rahim NY, Suah FBM
    Int J Biol Macromol, 2021 Nov 30;191:1151-1163.
    PMID: 34600954 DOI: 10.1016/j.ijbiomac.2021.09.179
    The presence of dyes in the aquatic environment as a result of anthropogenic activities, especially textile industries, is a critical environmental challenge that hinders the availability of potable water. Different wastewater treatment approaches have been used to remediate dyes in aquatic environments; however, most of these approaches are limited by factors ranging from high cost to the incomplete removal of the dyes and contaminants. Thus, the use of adsorption as a water treatment technology to remove dyes and other contaminants has been widely investigated using different adsorbents. This study evaluated the significance of chitosan as a viable adsorbent for removing dyes from water treatment. We summarised the literature and research results obtained between 2009 and 2020 regarding the adsorption of dyes onto chitosan and modified chitosan-based adsorbents prepared through physical and chemical processing, including crosslinking impregnation, grafting, and membrane preparation. Furthermore, we demonstrated the effects of various chitosan-based materials and modifications; they all improve the properties of chitosan by promoting the adsorption of dyes. Hence, the application of chitosan-based materials with various modifications should be considered a cutting-edge approach for the remediation of dyes and other contaminants in aquatic environments toward the global aim of making potable water globally available.
    Matched MeSH terms: Chitosan/chemistry*
  4. Malek NNA, Jawad AH, Ismail K, Razuan R, ALOthman ZA
    Int J Biol Macromol, 2021 Oct 31;189:464-476.
    PMID: 34450144 DOI: 10.1016/j.ijbiomac.2021.08.160
    A magnetic biocomposite blend of chitosan-polyvinyl alcohol/fly ash (m-Cs-PVA/FA) was developed by adding fly ash (FA) microparticles into the polymeric matrix of magnetic chitosan-polyvinyl alcohol (m-Cs-PVA). The effectiveness of m-Cs-PVA/FA as an adsorbent to remove textile dye (reactive orange 16, RO16) from aquatic environment was evaluated. The optimum adsorption key parameters and their significant interactions were determined by Box-Behnken Design (BBD). The analysis of variance (ANOVA) indicates the significant interactions can be observed between m-Cs-PVA/FA dose with solution pH, and m-Cs-PVA/FA dose with working temperature. Considering these significant interactions, the highest removal of RO16 (%) was found 90.3% at m-Cs-PVA/FA dose (0.06 g), solution pH (4), working temperature (30 °C), and contact time (17.5 min). The results of adsorption kinetics revealed that the RO16 adsorption was better described by the pseudo-second-order model. The results of adsorption isotherm indicated a multilayer adsorption process as well described by Freundlich model with maximum adsorption capacity of 123.8 mg/g at 30 °C. An external magnetic field can be easily applied to recover the adsorbent (m-Cs-PVA/FA). The results supported that the synthesized m-Cs-PVA/FA presents itself as an effective and promising adsorbent for textile dye with preferable adsorption capacity and separation ability during and after the adsorption process.
    Matched MeSH terms: Chitosan/chemistry*
  5. Khan MUA, Iqbal I, Ansari MNM, Razak SIA, Raza MA, Sajjad A, et al.
    Molecules, 2021 Sep 30;26(19).
    PMID: 34641480 DOI: 10.3390/molecules26195937
    The present research is based on the fabrication preparation of CS/PVA/GG blended hydrogel with nontoxic tetra orthosilicate (TEOS) for sustained paracetamol release. Different TEOS percentages were used because of their nontoxic behavior to study newly designed hydrogels' crosslinking and physicochemical properties. These hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and wetting to determine the functional, surface morphology, hydrophilic, or hydrophobic properties. The swelling analysis in different media, degradation in PBS, and drug release kinetics were conducted to observe their response against corresponding media. The FTIR analysis confirmed the components added and crosslinking between them, and surface morphology confirmed different surface and wetting behavior due to different crosslinking. In various solvents, including water, buffer, and electrolyte solutions, the swelling behaviour of hydrogel was investigated and observed that TEOS amount caused less hydrogel swelling. In acidic pH, hydrogels swell the most, while they swell the least at pH 7 or higher. These hydrogels are pH-sensitive and appropriate for controlled drug release. These hydrogels demonstrated that, as the ionic concentration was increased, swelling decreased due to decreased osmotic pressure in various electrolyte solutions. The antimicrobial analysis revealed that these hydrogels are highly antibacterial against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains. The drug release mechanism was 98% in phosphate buffer saline (PBS) media at pH 7.4 in 140 min. To analyze drug release behaviour, the drug release kinetics was assessed against different mathematical models (such as zero and first order, Higuchi, Baker-Lonsdale, Hixson, and Peppas). It was found that hydrogel (CPG2) follows the Peppas model with the highest value of regression (R2 = 0.98509). Hence, from the results, these hydrogels could be a potential biomaterial for wound dressing in biomedical applications.
    Matched MeSH terms: Chitosan/chemistry*
  6. Ching KY, Andriotis O, Sengers B, Stolz M
    J Biomater Appl, 2021 09;36(3):503-516.
    PMID: 33730922 DOI: 10.1177/08853282211002015
    Towards optimizing the growth of extracellular matrix to produce repair cartilage for healing articular cartilage (AC) defects in joints, scaffold-based tissue engineering approaches have recently become a focus of clinical research. Scaffold-based approaches by electrospinning aim to support the differentiation of chondrocytes by providing an ultrastructure similar to the fibrillar meshwork in native cartilage. In a first step, we demonstrate how the blending of chitosan with poly(ethylene oxide) (PEO) allows concentrated chitosan solution to become electrospinnable. The chitosan-based scaffolds share the chemical structure and characteristics of glycosaminoglycans, which are important structural components of the cartilage extracellular matrix. Electrospinning produced nanofibrils of ∼100 nm thickness that are closely mimicking the size of collagen fibrils in human AC. The polymer scaffolds were stabilized in physiological conditions and their stiffness was tuned by introducing the biocompatible natural crosslinker genipin. We produced scaffolds that were crosslinked with 1.0% genipin to obtain values of stiffness that were in between the stiffness of the superficial zone human AC of 600 ± 150 kPa and deep zone AC of 1854 ± 483 kPa, whereas the stiffness of 1.5% genipin crosslinked scaffold was similar to the stiffness of deep zone AC. The scaffolds were degradable, which was indicated by changes in the fibril structure and a decrease in the scaffold stiffness after seven months. Histological and immunohistochemical analysis after three weeks of culture with human articular chondrocytes (HACs) showed a cell viability of over 90% on the scaffolds and new extracellular matrix deposited on the scaffolds.
    Matched MeSH terms: Chitosan/chemistry*
  7. Azmana M, Mahmood S, Hilles AR, Rahman A, Arifin MAB, Ahmed S
    Int J Biol Macromol, 2021 Aug 31;185:832-848.
    PMID: 34237361 DOI: 10.1016/j.ijbiomac.2021.07.023
    Over the last few years, several attempts have been made to replace petrochemical products with renewable and biodegradable components. The most challenging part of this approach is to obtain bio-based materials with properties and functions equivalent to those of synthetic products. Various naturally occurring polymers such as starch, collagen, alginate, cellulose, and chitin represent attractive candidates as they could reduce dependence on synthetic products and consequently positively impact the environment. Chitosan is also a unique bio-based polymer with excellent intrinsic properties. It is known for its anti-bacterial and film-forming properties, has high mechanical strength and good thermal stability. Nanotechnology has also applied chitosan-based materials in its most recent achievements. Therefore, numerous chitosan-based bionanocomposites with improved physical and chemical characteristics have been developed in an eco-friendly and cost-effective approach. This review discusses various sources of chitosan, its properties and methods of modification. Also, this work focuses on diverse preparation techniques of chitosan-based bionanocomposites and their emerging application in various sectors. Additionally, this review sheds light on future research scope with some drawbacks and challenges to motivate the researchers for future outstanding research works.
    Matched MeSH terms: Chitosan/chemistry*
  8. Xu FX, Ooi CW, Liu BL, Song CP, Chiu CY, Wang CY, et al.
    Int J Biol Macromol, 2021 Jun 30;181:508-520.
    PMID: 33775766 DOI: 10.1016/j.ijbiomac.2021.03.151
    This study aimed to develop a novel electrospun polyacrylonitrile (PAN) nanofiber membrane with the enhanced antibacterial property. The PAN nanofiber membrane was first subjected to alkaline hydrolysis treatment, and the treated membrane was subsequently grafted with chitosan (CS) to obtain a CS-modified nanofiber membrane (P-COOH-CS). The modified membrane was then coupled with different dye molecules to form P-COOH-CS-Dye membranes. Lastly, poly(hexamethylene biguanide) hydrochloride (PHMB) was immobilized on the modified membrane to produce P-COOH-CS-Dye-PHMB. Physical characterization studies were conducted on all the synthesized nanofiber membranes. The antibacterial efficacies of nanofiber membranes prepared under different synthesis conditions were evaluated systematically. Under the optimum synthesis conditions, P-COOH-CS-Dye-PHMB was highly effective in disinfecting a high concentration of Escherichia coli, with an antibacterial efficacy of approximately 100%. Additionally, the P-COOH-CS-Dye-PHMB exhibited an outstanding wash durability as its antibacterial efficacy was only reduced in the range of 5%-7% even after 5 repeated cycles of treatment. Overall, the experimental results of this study suggested that the P-COOH-CS-Dye-PHMB is a promising antibacterial nanofiber membrane that can be adopted in the food, pharmaceutical, and textile industries.
    Matched MeSH terms: Chitosan/chemistry*
  9. Wu JY, Ooi CW, Song CP, Wang CY, Liu BL, Lin GY, et al.
    Carbohydr Polym, 2021 Jun 15;262:117910.
    PMID: 33838797 DOI: 10.1016/j.carbpol.2021.117910
    N-[(2-hydroxyl-3-trimethylammonium) propyl] chitosan chloride (HTCC), which is a type of chitosan derivative with quaternary ammonium groups, possesses a higher antibacterial activity as compared to the pristine chitosan. The nanofiber membranes made of HTCC are attractive for applications demanding for antibacterial function. However, the hydrophilic nature of HTCC makes it unsuitable for electrospinning of nanofibers. Hence, biodegradable polyvinyl alcohol (PVA) was proposed as an additive to improve the electrospinnability of HTCC. In this work, PVA/HTCC nanofiber membrane was crosslinked with the blocked diisocyanate (BI) to enhance the stability of nanofiber membrane in water. Microbiological assessments showed that the PVA/HTCC/BI nanofiber membranes possessed a good antibacterial efficacy (∼100 %) against E. coli. Moreover, the biocompatibility of PVA/HTCC/BI nanofiber membrane was proven by the cytotoxicity test on mouse fibroblasts. These promising results indicated that the PVA/HTCC/BI nanofiber membrane can be a promising material for food packaging and as a potential wound dressing for skin regeneration.
    Matched MeSH terms: Chitosan/chemistry*
  10. Alirezalu K, Pirouzi S, Yaghoubi M, Karimi-Dehkordi M, Jafarzadeh S, Mousavi Khaneghah A
    Meat Sci, 2021 Jun;176:108475.
    PMID: 33684807 DOI: 10.1016/j.meatsci.2021.108475
    In the current study, the effect on packaged beef fillets (1 × 5 × 8 cm) of using active chitosan film (1%) was investigated. The fillets were stored at 4 °C for 12 days, and the film contained ɛ-polylysine (ɛ-PL) (0.3, 0.6, and 0.9% w/w). Chemical, microbiological, sensory properties, and quality indices of the fillets were investigated. Added to these factors was an assessment of the influence of ɛ-polylysine incorporation on the optical, structural, barrier, and mechanical specifications (elongation at break and tensile strength) of chitosan films. Based on the findings, a significant difference among the corresponding values to thickness, color, water vapor permeability (WVP), and mechanical specifications between the treated films by ɛ-PL and untreated films were noted. In addition, higher values of thickness and tensile strength were correlated with ɛ-PL added active chitosan films while compared with control samples. Additionally, no significant differences regarding the proximate composition (including protein, moisture, and fat) among beef fillet samples were observed. In this regard, due to significantly lower levels of pH, TVB-N, and TBARS ɛ-PL in enriched films, this technique demonstrated some protective effects on beef fillets. Another observation was that lower levels of the total viable count, coliform, mold, yeasts, and higher sensory properties were significantly associated with samples with added ɛ-PL (0.9%). Therefore, adding ɛ-PL into chitosan films could be introduced as an effective technique to extend the shelf life of beef fillets and maintain their quality indices during refrigerated storage.
    Matched MeSH terms: Chitosan/chemistry
  11. Rizal S, Saharudin NI, Olaiya NG, Khalil HPSA, Haafiz MKM, Ikramullah I, et al.
    Molecules, 2021 Apr 01;26(7).
    PMID: 33916094 DOI: 10.3390/molecules26072008
    The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.
    Matched MeSH terms: Chitosan/chemistry*
  12. Vallejo-Domínguez D, Rubio-Rosas E, Aguila-Almanza E, Hernández-Cocoletzi H, Ramos-Cassellis ME, Luna-Guevara ML, et al.
    Ultrason Sonochem, 2021 Apr;72:105417.
    PMID: 33352467 DOI: 10.1016/j.ultsonch.2020.105417
    Recently, chitin and chitosan are widely investigated for food preservation and active packaging applications. Chemical, as well as biological methods, are usually adopted for the production of these biopolymers. In this study, modification to a chemical method of chitin synthesis from shrimp shells has been proposed through the application of high-frequency ultrasound. The impact of sonication time on the deproteinization step of chitin and chitosan preparation was examined. The chemical identities of chitin and chitosan were verified using infrared spectroscopy. The influence of ultrasound on the deacetylation degree, molecular weight and particle size of the biopolymer products was analysed. The microscopic characteristics, crystallinity and the colour characteristics of the as-obtained biopolymers were investigated. Application of ultrasound for the production of biopolymers reduced the protein content as well as the particle size of chitin. Chitosan of high deacetylation degree and medium molecular weight was produced through ultrasound assistance. Finally, the as-derived chitosan was applied for beef preservation. High values of luminosity, chromatid and chrome were noted for the beef samples preserved using chitosan films, which were obtained by employing biopolymer subjected to sonication for 15, 25 and 40 min. Notably; these characteristics were maintained even after ten days of packaging. The molecular weight of these samples are 73.61 KDa, 86.82 KDa and 55.66 KDa, while the deacetylation degree are 80.60%, 92.86% and 94.03%, respectively; in the same order, the particle size of chitosan are 35.70 μm, 25.51 μm and 20.10 μm.
    Matched MeSH terms: Chitosan/chemistry*
  13. Chang SH
    Carbohydr Polym, 2021 Mar 15;256:117423.
    PMID: 33483013 DOI: 10.1016/j.carbpol.2020.117423
    Chitosan, a prestigious versatile biopolymer, has recently received considerable attention as a promising biosorbent for recovering gold ions, mainly Au(III), from aqueous solutions, particularly in modified forms. Confirming the assertion, this paper provides an up-to-date overview of Au(III) recovery from aqueous solutions by raw (unmodified) and modified chitosan. A particular emphasis is placed on the raw chitosan and its synthesis from chitin, characteristics of raw chitosan and their effects on metal sorption, modifications of raw chitosan for Au(III) sorption, and characterization of raw chitosan before and after modifications for Au(III) sorption. Comparisons of the sorption (conditions, percentage, capacity, selectivity, isotherms, thermodynamics, kinetics, and mechanisms), desorption (agents and percentage), and reusable properties between raw and modified chitosan in Au(III) recovery from aqueous solutions are also outlined and discussed. The major challenges and future prospects towards the large-scale applications of modified chitosan in Au(III) recovery from aqueous solutions are also addressed.
    Matched MeSH terms: Chitosan/chemistry*
  14. Shi W, Ching YC, Chuah CH
    Int J Biol Macromol, 2021 Feb 15;170:751-767.
    PMID: 33412201 DOI: 10.1016/j.ijbiomac.2020.12.214
    Spherical aerogels are not easily broken during use and are easier to transport and store which can be used as templates for drug delivery. This review summarizes the possible approaches for the preparation of aerogel beads and microspheres based on chitosan and cellulose, an overview to the methods of manufacturing droplets is presented, afterwards, the transition mechanisms from sol to a spherical gel are reviewed in detail followed by different drying processes to obtain spherical aerogels with porous structures. Additionally, a specific focus is given to aerogel beads and microspheres to be regarded as drug delivery carriers. Furthermore, a core/shell architecture of aerogel beads and microspheres for controlled drug release is described and subjected to inspire readers to create novel drug release system. Finally, the conclusions and outlooks of aerogel beads and microspheres for drug delivery are summarized.
    Matched MeSH terms: Chitosan/chemistry*
  15. Surjit Singh CK, Lim HP, Tey BT, Chan ES
    Carbohydr Polym, 2021 Jan 01;251:117110.
    PMID: 33142647 DOI: 10.1016/j.carbpol.2020.117110
    The commercial application of liquid-state Pickering emulsions in food systems remains a major challenge. In this study, we developed a spray-dried Pickering emulsion powder using chitosan as a Pickering emulsifier and alginate as a coating material. The functionality of the powder was evaluated in terms of its oxidative stability, pH-responsiveness, mucoadhesivity, and lipid digestibility. The Pickering emulsion powder was oxidatively more stable than the conventional emulsion powder stabilized by gum Arabic. The powder exhibited pH-responsiveness, whereby it remained intact in acidic pH, but dissolved to release the emulsion in 'Pickering form' at near-neutral pH. The Pickering emulsion powder was also mucoadhesive and could be digested by lipase in a controlled manner. These findings suggested that the multi-functional Pickering emulsion powder could be a potential delivery system for applications in the food industry.
    Matched MeSH terms: Chitosan/chemistry*
  16. Tee YN, Kumar PV, Maki MAA, Elumalai M, Rahman SAKMEH, Cheah SC
    Curr Pharm Biotechnol, 2021;22(7):969-982.
    PMID: 33342408 DOI: 10.2174/1389201021666201218124450
    BACKGROUND: Recombinant Keratinocyte Growth Factor (rHuKGF) is a therapeutic protein used widely in oral mucositis after chemotherapy in various cancers, stimulating lung morphogenesis and gastrointestinal tract cell proliferation. In this research study, chitosan-rHuKGF polymeric complex was implemented to improve the stability of rHuKGF and used as rejuvenation therapy for the treatment of oral mucositis in cancer patients.

    OBJECTIVE: Complexation of rHuKGF with mucoadhesive low molecular weight chitosan to protect rHuKGF from proteolysis and investigate the effect of chitosan-rHuKGF complex on the proliferation rate of FHs 74 Int cells.

    METHODS: The interaction between chitosan and rHuKGF was studied by molecular docking. Malvern ZetaSizer Nano Zs and Fourier-Transform Infrared spectroscopy (FTIR) tests were carried out to characterize the chitosan-rHuKGF complex. In addition, SDS-PAGE was performed to investigate the interaction between chitosan-rHuKGF complex and pepsin. The effect of chitosan-rHuKGF complex on the proliferation rate of FHs 74 Int cells was studied by MTT assay.

    RESULTS: Chitosan-rHuKGF complex was formed through the hydrogen bonding proven by the docking studies. A stable chitosan-rHuKGF complex was formed at pH 4.5 and was protected from proteolysis and assessed by SDS PAGE. According to the MTT assay results, chitosan-rHuKGF complex increased the cell proliferation rate of FHs 74 Int cells.

    CONCLUSION: The developed complex improved the stability and the biological function of rHuKGF.

    Matched MeSH terms: Chitosan/chemistry*
  17. Maluin FN, Hussein MZ, Yusof NA, Fakurazi S, Maznah Z, Idris AS, et al.
    Sci Rep, 2020 12 18;10(1):22323.
    PMID: 33339951 DOI: 10.1038/s41598-020-79335-6
    The nanoformulations of pesticides have shown great interest from many parties due to their slow release capability and site-specific delivery. Hence, in this work, a new nanoformulation of a fungicide, namely chitosan-hexaconazole nanoparticles with a mean diameter size of 18 nm was subjected to the residual analysis on oil palm tissue, leaf and palm oil (crude palm oil and crude palm kernel oil) using a quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with the gas chromatography-micro electron capture detector (GC-µECD). The chitosan-hexaconazole nanoparticles were applied using the trunk injection method at 4.5 g a.i./palm (standard single dose) and 9.0 g a.i./palm (double dose). The fungicide residue was analyzed at 0 (6 h after application), 1, 3, 7, 14, 30, 60, 90, and 120 days after treatment. The palm oil matrices; the crude palm oil (CPO) and crude palm kernel oil (CPKO) were found to be residue-free. However, it was observed that high accumulation of the fungicide in the stem tissue and leaf after the treatment using the chitosan-hexaconazole nanoparticles, which is good for better bioavailability for the treatment of the fungi, Ganoderma boninense. The dissipation kinetic at double dose treatment in the tissue and leaf was found to govern by the second-order kinetic with half-lives (t1/2) of 383 and 515 days, respectively.
    Matched MeSH terms: Chitosan/chemistry
  18. Sadiq AC, Rahim NY, Suah FBM
    Int J Biol Macromol, 2020 Dec 01;164:3965-3973.
    PMID: 32910963 DOI: 10.1016/j.ijbiomac.2020.09.029
    Chitosan-deep eutectic solvent (DES) beads were prepared from chitosan and DESs. The DESs used were choline chloride-urea (DES A) and choline chloride-glycerol (DES B). Both chitosan-DES beads were used to remove malachite green (MG) dye from an aqueous solution. The optimum pH for chitosan-DES A was recorded at pH 8.0 while optimum pH for chitosan-DES B was pH 9.0. The maximum adsorption capacity obtained for chitosan-DES A and chitosan-DES B were 6.54 mg/g and 8.64 mg/g, respectively. The optimum conditions for both chitosan-DES beads to remove MG were 0.08 g of adsorbent and 20 min of agitation time. Five kinetic models were applied to analyse the data and the results showed that the pseudo-second-order and intraparticle diffusion model fitted best with R2 > 0.999. For the adsorption capacity, results show that the Freundlich and Langmuir adsorption isotherms fitted well with chitosan-DES A and chitosan-DES B, respectively. The maximum adsorption capacities (qmax) obtained from chitosan-DES A and chitosan-DES B were 1.43 mg/g and 17.86 mg/g, respectively. Desorption indicated good performance in practical applications.
    Matched MeSH terms: Chitosan/chemistry*
  19. Jawad AH, Abdulhameed AS, Malek NNA, ALOthman ZA
    Int J Biol Macromol, 2020 Dec 01;164:4218-4230.
    PMID: 32861784 DOI: 10.1016/j.ijbiomac.2020.08.201
    In current research work, chitosan (Chi) was subjected to subsequent physical and chemical modifications by incorporating kaolin clay (KA) into its polymeric structure, and crosslinking process with a covalent cross-linker namely epichlorohydrin (ECH) respectively. The final product of crosslinked chitosan-epichlorohydrin/kaolin (Chi-ECH/KA) composite was successfully applied for color removal and chemical oxygen demand (COD) reduction of textile dye namely reactive blue 19 dye (RB19) from aqueous environment. The influence of pertinent parameters, i.e. A: Chi-ECH/KA dose (0.02-0.1 g), B: pH (4-10), and C: time (5-30 min) on the RB19 color removal and COD reduction were statistically optimized by using response surface methodology with Box-Behnken design (RSM-BBD). The experimental data of the adsorption kinetic and the adsorption isotherm demonstrated a better fitness to pseudo-second order model and Langmuir isotherm model respectively. Excellent absorption ability of 560.9 mg/g was recorded for Chi-ECH/KA composite. The calculated thermodynamic functions clarified that the RB19 adsorption process was endothermic and spontaneous in nature. The mechanism of RB19 adsorption onto the Chi-ECH/KA may include electrostatic interactions, hydrogen bonding, Yoshida H-bonding, and n-π interactions. This study introduces Chi-ECH/KA composite as an eco-friendly, potential and multi-function composite bio adsorbent for removal of textile dye and COD reduction from aqueous environment.
    Matched MeSH terms: Chitosan/chemistry*
  20. Bande F, Arshad SS, Bejo MH, Omar AR, Moeini H, Khadkodaei S, et al.
    Microb Pathog, 2020 Dec;149:104560.
    PMID: 33068733 DOI: 10.1016/j.micpath.2020.104560
    Infectious Bronchitis (IB) is an economically important avian disease that considerably threatens the global poultry industry. This is partly, as a result of its negative consequences on egg production, weight gain as well as mortality rate.The disease is caused by a constantly evolving avian infectious bronchitis virus whose isolates are classified into several serotypes and genotypes that demonstrate little or no cross protection. In order to curb the menace of the disease therefore, broad based vaccines are urgently needed. The aim of this study was to develop a recombinant DNA vaccine candidate for improved protection of avian infectious bronchitis in poultry. Using bioinformatics and molecular cloning procedures, sets of monovalent and bivalent DNA vaccine constructs were developed based on the S1 glycoprotein from classical and variants IBV strains namely, M41 and CR88 respectively. The candidate vaccine was then encapsulated with a chitosan and saponin formulated nanoparticle for enhanced immunogenicity and protective capacity. RT-PCR assay and IFAT were used to confirm the transcriptional and translational expression of the encoded proteins respectively, while ELISA and Flow-cytometry were used to evaluate the immunogenicity of the candidate vaccine following immunization of various SPF chicken groups (A-F). Furthermore, histopathological changes and virus shedding were determined by quantitative realtime PCR assay and lesion scoring procedure respectively following challenge of various subgroups with respective wild-type IBV viruses. Results obtained from this study showed that, groups vaccinated with a bivalent DNA vaccine construct (pBudCR88-S1/M41-S1) had a significant increase in anti-IBV antibodies, CD3+ and CD8+ T-cells responses as compared to non-vaccinated groups. Likewise, the bivalent vaccine candidate significantly decreased the oropharyngeal and cloacal virus shedding (p < 0.05) compared to non-vaccinated control. Chickens immunized with the bivalent vaccine also exhibited milder clinical signs as well as low tracheal and kidney lesion scores following virus challenge when compared to control groups. Collectively, the present study demonstrated that bivalent DNA vaccine co-expressing dual S1 glycoprotein induced strong immune responses capable of protecting chickens against infection with both M41 and CR88 IBV strains. Moreso, it was evident that encapsulation of the vaccine with chitosan-saponin nanoparticle further enhanced immune responses and abrogates the need for multiple booster administration of vaccine. Therefore, the bivalent DNA vaccine could serve as efficient and effective alternative strategy for the control of IB in poultry.
    Matched MeSH terms: Chitosan/chemistry
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