Displaying publications 21 - 40 of 414 in total

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  1. Vakili M, Rafatullah M, Ibrahim MH, Abdullah AZ, Salamatinia B, Gholami Z
    Carbohydr Polym, 2016 Feb 10;137:139-146.
    PMID: 26686114 DOI: 10.1016/j.carbpol.2015.09.017
    Adsorption performance of chitosan (CS) hydrogel beads was investigated after impregnation of CS with hexadecylamine (HDA) as a cationic surfactant, for the elimination of reactive blue 4 (RB4) from wastewater. The CS/HDA beads formed with 3.8% HDA were the most effective adsorbent. The adsorption capacity was increased by 1.43 times from 317 mg/g (CS) to 454 mg/g (CS/HDA). The RB4 removal increased with decrease in the pH of dye solution from 4 to 9. The isotherm data obtained from RB4 adsorption on CS and CS/HDA are adequately described by Freundlich model (R(2)=0.946 and 0.934, χ(2)=22.414 and 64.761). The kinetic study revealed that the pseudo-second-order rate model (R(2)=0.996 and 0.997) was in better agreement with the experimental data. The negative values of ΔG° (-2.28 and -6.30 kJ/mol) and ΔH° (-172.18 and -101.62 kJ/mol) for CS beads and HDA modified CS beads, respectively; suggested a spontaneous and exothermic process for RB4 adsorption.
    Matched MeSH terms: Chitosan/chemistry*
  2. Ang LF, Por LY, Yam MF
    PLoS One, 2013;8(8):e70597.
    PMID: 23940599 DOI: 10.1371/journal.pone.0070597
    Two chitosan samples (medium molecular weight (MMCHI) and low molecular weight (LMCHI)) were investigated as an enzyme immobilization matrix for the fabrication of a glucose biosensor. Chitosan membranes prepared from acetic acid were flexible, transparent, smooth and quick-drying. The FTIR spectra showed the existence of intermolecular interactions between chitosan and glucose oxidase (GOD). Higher catalytic activities were observed on for GOD-MMCHI than GOD-LMCHI and for those crosslinked with glutaraldehyde than using the adsorption technique. Enzyme loading greater than 0.6 mg decreased the activity. Under optimum conditions (pH 6.0, 35°C and applied potential of 0.6 V) response times of 85 s and 65 s were observed for medium molecular weight chitosan glucose biosensor (GOD-MMCHI/PT) and low molecular weight chitosan glucose biosensor (GOD-LMCHI/PT), respectively. The apparent Michaelis-Menten constant ([Formula: see text]) was found to be 12.737 mM for GOD-MMCHI/PT and 17.692 mM for GOD-LMCHI/PT. This indicated that GOD-MMCHI/PT had greater affinity for the enzyme. Moreover, GOD-MMCHI/PT showed higher sensitivity (52.3666 nA/mM glucose) when compared with GOD-LMCHI/PT (9.8579 nA/mM glucose) at S/N>3. Better repeatability and reproducibility were achieved with GOD-MMCHI/PT than GOD-LMCHI/PT regarding glucose measurement. GOD-MMCHI/PT was found to give the highest enzymatic activity among the electrodes under investigation. The extent of interference encountered by GOD-MMCHI/PT and GOD-LMCHI/PT was not significantly different. Although the Nafion coated biosensor significantly reduced the signal due to the interferents under study, it also significantly reduced the response to glucose. The performance of the biosensors in the determination of glucose in rat serum was evaluated. Comparatively better accuracy and recovery results were obtained for GOD-MMCHI/PT. Hence, GOD-MMCHI/PT showed a better performance when compared with GOD-LMCHI/PT. In conclusion, chitosan membranes shave the potential to be a suitable matrix for the development of glucose biosensors.
    Matched MeSH terms: Chitosan/chemistry*
  3. Ahmad MB, Tay MY, Shameli K, Hussein MZ, Lim JJ
    Int J Mol Sci, 2011;12(8):4872-84.
    PMID: 21954331 DOI: 10.3390/ijms12084872
    This paper presents the green synthesis of silver nanoparticles (Ag NPs) in aqueous medium. This method was performed by reducing AgNO(3) in different stirring times of reaction at a moderate temperature using green agents, chitosan (Cts) and polyethylene glycol (PEG). In this work, silver nitrate (AgNO(3)) was used as the silver precursor while Cts and PEG were used as the solid support and polymeric stabilizer. The properties of Ag/Cts/PEG nanocomposites (NCs) were studied under different stirring times of reaction. The developed Ag/Cts/PEG NCs were then characterized by the ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy.
    Matched MeSH terms: Chitosan/chemistry*
  4. Wan Ngah WS, Hanafiah MA, Yong SS
    Colloids Surf B Biointerfaces, 2008 Aug 1;65(1):18-24.
    PMID: 18359205 DOI: 10.1016/j.colsurfb.2008.02.007
    The adsorption of humic acid on crosslinked chitosan-epichlorohydrin (chitosan-ECH) beads was investigated. Chitosan-ECH beads were characterized by Fourier transform infrared spectroscopy (FTIR), surface area and pore size analyses, and scanning electron microscopy (SEM). Batch adsorption experiments were carried out and optimum humic acid adsorption on chitosan-ECH beads occurred at pH 6.0, agitation rate of 300 rpm and contact time of 50 min. Adsorption equilibrium isotherms were analyzed by Langmuir and Freundlich models. Freundlich model was found to show the best fit for experimental data while the maximum adsorption capacity determined from Langmuir model was 44.84 mg g(-1). The adsorption of humic acid on chitosan-ECH beads was best described with pseudo-first-order kinetic model. For desorption study, more than 60% of humic acid could be desorbed from the adsorbent using 1.0M HCl for 180 min.
    Matched MeSH terms: Chitosan/chemistry
  5. H P S AK, Saurabh CK, A S A, Nurul Fazita MR, Syakir MI, Davoudpour Y, et al.
    Carbohydr Polym, 2016 Oct 05;150:216-26.
    PMID: 27312632 DOI: 10.1016/j.carbpol.2016.05.028
    Chitin is one of the most abundant natural polymers in world and it is used for the production of chitosan by deacetylation. Chitosan is antibacterial in nature, non-toxic, and biodegradable thus it can be used for the production of biodegradable film which is a green alternative to commercially available synthetic counterparts. However, their poor mechanical and thermal properties restricted its wide spread applications. Chitosan is highly compatible with other biopolymers thus its blending with cellulose and/or incorporation of nanofiber isolated from cellulose namely cellulose nanofiber and cellulose nanowhiskers are generally useful. Cellulosic fibers in nano scale are attractive reinforcement in chitosan to produce environmental friendly composite films with improved physical properties. Thus chitosan based composites have wide applicability and potential in the field of biomedical, packaging and water treatment. This review summarises properties and preparation procedure of chitosan-cellulose blends and nano size cellulose reinforcement in chitosan bionanocomposites for different applications.
    Matched MeSH terms: Chitosan/chemistry*
  6. El Zowalaty ME, Hussein Al Ali SH, Husseiny MI, Geilich BM, Webster TJ, Hussein MZ
    Int J Nanomedicine, 2015;10:3269-74.
    PMID: 25995633 DOI: 10.2147/IJN.S74469
    Magnetic nanoparticles (MNPs) were synthesized by the coprecipitation of Fe(2+) and Fe(3+) iron salts in alkali media. MNPs were coated by chitosan (CS) to produce CS-MNPs. Streptomycin (Strep) was loaded onto the surface of CS-MNPs to form a Strep-CS-MNP nanocomposite. MNPs, CS-MNPs, and the nanocomposites were subsequently characterized using X-ray diffraction and were evaluated for their antibacterial activity. The antimicrobial activity of the as-synthesized nanoparticles was evaluated using different Gram-positive and Gram-negative bacteria, as well as Mycobacterium tuberculosis. For the first time, it was found that the nanoparticles showed antimicrobial activities against the tested microorganisms (albeit with a more pronounced effect against Gram-negative than Gram-positive bacteria), and thus, should be further studied as a novel nano-antibiotic for numerous antimicrobial and antituberculosis applications. Moreover, since these nanoparticle bacteria fighters are magnetic, one can easily envision magnetic field direction of these nanoparticles to fight unwanted microorganism presence on demand. Due to the ability of magnetic nanoparticles to increase the sensitivity of imaging modalities (such as magnetic resonance imaging), these novel nanoparticles can also be used to diagnose the presence of such microorganisms. In summary, although requiring further investigation, this study introduces for the first time a new type of magnetic nanoparticle with microorganism theranostic properties as a potential tool to both diagnose and treat diverse microbial and tuberculosis infections.
    Matched MeSH terms: Chitosan/chemistry*
  7. Aziz SB, Hamsan MH, Kadir MFZ, Karim WO, Abdullah RM
    Int J Mol Sci, 2019 Jul 09;20(13).
    PMID: 31323971 DOI: 10.3390/ijms20133369
    Solid polymer blend electrolyte membranes (SPBEM) composed of chitosan and dextran with the incorporation of various amounts of lithium perchlorate (LiClO4) were synthesized. The complexation of the polymer blend electrolytes with the salt was examined using FTIR spectroscopy and X-ray diffraction (XRD). The morphology of the SPBEs was also investigated using field emission scanning electron microscopy (FESEM). The ion transport behavior of the membrane films was measured using impedance spectroscopy. The membrane with highest LiClO4 content was found to exhibit the highest conductivity of 5.16 × 10-3 S/cm. Ionic (ti) and electronic (te) transference numbers for the highest conducting electrolyte were found to be 0.98 and 0.02, respectively. Electrochemical stability was estimated from linear sweep voltammetry and found to be up to ~2.3V for the Li+ ion conducting electrolyte. The only existence of electrical double charging at the surface of electrodes was evidenced from the absence of peaks in cyclic voltammetry (CV) plot. The discharge slope was observed to be almost linear, confirming the capacitive behavior of the EDLC. The performance of synthesized EDLC was studied using CV and charge-discharge techniques. The highest specific capacitance was achieved to be 8.7 F·g-1 at 20th cycle. The efficiency (η) was observed to be at 92.8% and remained constant at 92.0% up to 100 cycles. The EDLC was considered to have a reasonable electrode-electrolyte contact, in which η exceeds 90.0%. It was determined that equivalent series resistance (Resr) is quite low and varies from 150 to 180 Ω over the 100 cycles. Energy density (Ed) was found to be 1.21 Wh·kg-1 at the 1st cycle and then remained stable at 0.86 Wh·kg-1 up to 100 cycles. The interesting observation is that the value of Pd increases back to 685 W·kg-1 up to 80 cycles.
    Matched MeSH terms: Chitosan/chemistry*
  8. Sherlala AIA, Raman AAA, Bello MM, Buthiyappan A
    J Environ Manage, 2019 Sep 15;246:547-556.
    PMID: 31202019 DOI: 10.1016/j.jenvman.2019.05.117
    Chitosan-magnetic-graphene oxide (CMGO) nanocomposite was prepared for arsenic adsorption. The nanocomposite was characterized through BET, FTIR, FESEM, EDX, and VSM analyses. These characterizations confirmed the formation of CMGO nanocomposites with high specific surface area (152.38 m2/g) and excellent saturation magnetization (49.30 emu/g). Batch adsorption experiments were conducted to evaluate the performance of the nanocomposite in the adsorption of arsenic from aqueous solution. The effects of operational parameters, adsorption kinetic, equilibrium isotherm and thermodynamics were evaluated. The removal efficiency of arsenic increased with increasing adsorbent dosage and contact time. However, the effect of pH followed a different pattern, with the removal efficiency increasing from acidic to neutral pH, and then decreasing at alkaline conditions. The highest adsorption capacity (45 mg/g) and removal efficiency (61%) were obtained at pH 7.3. The adsorption kinetic followed a pseudo-second-order kinetic model. The analysis of adsorption isotherm shows that the adsorption data fitted well to Langmuir isotherm model, indicating a homogeneous process. Thermodynamic analysis shows that the adsorption of As(III) is exothermic and spontaneous. The superparamagnetic properties of the nanocomposite enabled the separation and recovery of the nanoparticles using an external magnetic field. Thus, the developed nanocomposite has a potential for arsenic remediation.
    Matched MeSH terms: Chitosan*
  9. Poornima P, Krithikadatta J, Ponraj RR, Velmurugan N, Kishen A
    BMC Oral Health, 2021 09 23;21(1):465.
    PMID: 34556107 DOI: 10.1186/s12903-021-01805-8
    BACKGROUND: Orthodontic treatment poses an increased risk of plaque accumulation and demineralisation of enamel leading to white spot lesion around the brackets. This parallel arm trial aims to assess the degree of bacterial plaque formation adjacent to orthodontic brackets, following the application of a chitosan-based varnish or chlorhexidene-fluoride varnish.

    METHODS: A total of 200 teeth from 20 patients undergoing fixed orthodontic therapy were assessed and biofilm formation around the brackets were recorded using the Bonded Bracket Index (Plaque index) at baseline and weekly for 6 weeks. The bacterial count and plaque pH at corresponding weekly intervals were also recorded. Following bracket bonding, the patients were cluster randomised to receive chitosan-based varnish-CHS (UNO Gel Bioschell, Germiphene corp., Brantford, Canada) or chlorhexidine-fluoride varnish-CFV (Cervitec F, Ivoclar Vivadent, Schaan, Liechtenstein) every week on the representative teeth respectively. BBI proportions were compared between groups at all time intervals using Chi square test. Mean plaque bacterial count and plaque pH were compared using Mann Whitney U test and Tukey's HSD test respectively.

    RESULTS: Baseline characteristics were similar between the groups: Mean age was CHS = 23 and CFV = 21; male to female ratio was CHS = 5/5, CFV = 7/3. At the end of 6 weeks, chitosan-based varnish performed equal to chlorhexidine-fluoride varnish (P > 0.05) with 98% and 95% of teeth with acceptable scores respectively. The plaque bacterial count significantly reduced at 6 weeks for both varnish compared to the baseline; The value for CHS was 0.43 ± 0.4 × 104 and CFV was 0.77 ± 0.64 × 104 CFU (P chitosan-based varnish and chlorhexidine-fluoride varnish reduced bacterial count, while the plaque pH remained neutral over a period of six weeks in patients undergoing fixed orthodontic therapy. The anti-plaque effects of the natural biopolymeric chitosan-based varnish was similar to that of chlorhexidine-fluoride varnish, a known chemotherapeutic agent. Registration: This trial protocol was registered with https://www.ctri.nic.in (CTRI/2019/05/018896). (Date of registration 02/05/2019).

    PROTOCOL: The protocol was not published before trial commencement.

    Matched MeSH terms: Chitosan*
  10. Abbasi Pirouz A, Abedi Karjiban R, Abu Bakar F, Selamat J
    Toxins (Basel), 2018 09 06;10(9).
    PMID: 30200553 DOI: 10.3390/toxins10090361
    A novel magnetic graphene oxide modified with chitosan (MGO-CTS) was synthesised as an adsorbent aimed to examine the simultaneous removal of mycotoxins. The composite was characterised by various procedures, namely Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and a scanning electron microscope (SEM). The adsorption evaluation was considered via pH effects, initial mycotoxin concentration, adsorption time and temperature. Adsorption isotherm data and kinetics experiments were acquired at the optimum pH 5 fit Freundlich isotherm as well as pseudo-second-order kinetic models. The thermodynamic results indicated that the adsorption of the mycotoxins was spontaneous, endothermic and favourable.
    Matched MeSH terms: Chitosan/chemistry*
  11. Garavand F, Cacciotti I, Vahedikia N, Rehman A, Tarhan Ö, Akbari-Alavijeh S, et al.
    Crit Rev Food Sci Nutr, 2022;62(5):1383-1416.
    PMID: 33153290 DOI: 10.1080/10408398.2020.1843133
    Chitosan is mainly derived from seafood by-products and the thereof chitosan nanoparticles (CNPs) are known as nontoxic, biocompatible, biodegradable and functionalized nanostructures. CNPs, as green fillers, showed an appropriate potential in reinforcement of various biodegradable composites for food packaging and biomedical applications. After evaluation of different fabrication approaches and characterization techniques of CNPs, the changes in physical, mechanical, thermal, structural, morphological, and antimicrobial attributes of nanobiocomposites as a result of CNPs addition are discussed. The influence of bioactive loaded-CNPs and hybrid CNPs with metal nanoparticles, graphene, and montmorillonite in nanocomposites is also presented. Finally, the safety aspects of CNPs-loaded structures are highlighted to evaluate their implementation in food packaging and biomedical systems. It can be concluded that regardless of a few drawbacks, CNPs are promising nanomaterials to improve various operational, structural and antimicrobial properties of biocomposites for various applications in food packaging, delivery systems and biomedical uses.
    Matched MeSH terms: Chitosan*
  12. Hussein-Al-Ali SH, Hussein MZ, Bullo S, Arulselvan P
    Int J Nanomedicine, 2021;16:6205-6216.
    PMID: 34526768 DOI: 10.2147/IJN.S312752
    Introduction: Traditional cancer therapies may have incomplete eradication of cancer or destroy the normal cells. Nanotechnology solves the demerit by a guide in surgical resection of tumors, targeted chemotherapies, selective to cancerous cells, etc. This new technology can reduce the risk to the patient and automatically increased the probability of survival. Toward this goal, novel iron oxide nanoparticles (IONPs) coupled with leukemia anti-cancer drug were prepared and assessed.

    Methods: The IONPs were prepared by the co-precipitation method using Fe+3/Fe+2ratio of 2:1. These IONPs were used as a carrier for chlorambucil (Chloramb), where the IONPs serve as the cores and chitosan (CS) as a polymeric shell to form Chloramb-CS-IONPs. The products were characterized using transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) analysis, Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM) analyses, and thermal gravimetric analysis (TGA).

    Results: The as-prepared IONPs were found to be magnetite (Fe3O4) and were coated by the CS polymer/Chloramb drug for the formation of the Chloramb-CS-IONPs. The average size for CS-IONPs and Chloramb-CS-IONPs nanocomposite was found to be 15 nm, with a drug loading of 19% for the letter. The release of the drug from the nanocomposite was found to be of a controlled-release manner with around 89.9% of the drug was released within about 5000 min and governed by the pseudo-second order. The in vitro cytotoxicity studies of CS-IONPs and Chloramb-CS-IONPs nanocomposite were tested on the normal fibroblast cell lines (3T3) and leukemia cancer cell lines (WEHI). Chloramb in Chloramb-CS-IONPs nanocomposite was found to be more efficient compared to its free form.

    Conclusion: This work shows that Chloramb-CS-IONPs nanocomposite is a promising candidate for magnetically targeted drug delivery for leukemia anti-cancer agents.

    Matched MeSH terms: Chitosan*
  13. 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*
  14. Chin JF, Heng ZW, Teoh HC, Chong WC, Pang YL
    Chemosphere, 2022 Mar;291(Pt 3):133035.
    PMID: 34848231 DOI: 10.1016/j.chemosphere.2021.133035
    Heavy metal contamination in water bodies is currently in an area of greater concern due to the adverse effects on human health. Despite the good adsorption performance of biochar, various modifications have been performed on the pristine biochar to further enhance its adsorption capability, at the same time overcome the difficulty of particles separation and mitigate the secondary pollution issues. In this review, the feasibility of chitosan-modified magnetic biochar for heavy metal removal from aqueous solution is evaluated by critically analysing existing research. The effective strategies that applied to introduce chitosan and magnetic substances into the biochar matrix are systematically reviewed. The physicochemical changes of the modified-biochar composite are expounded in terms of surface morphology, pore properties, specific surface area, surface functional groups and electromagnetism. The detailed information regarding the adsorption performances of various modified biochar towards different heavy metals and their respective underlying mechanisms are studied in-depth. The current review also analyses the kinetic and isotherm models that dominated the adsorption process and summarizes the common models that fitted well to most of the experimental adsorption data. Moreover, the operating parameters that affect the adsorption process which include solution pH, temperature, initial metal concentration, adsorbent dosage, contact time and the effect of interfering ions are explored. This review also outlines the stability of modified biochar and their regeneration rate after cycles of heavy metal removal process. Lastly, constructive suggestions on the future trends and directions are provided for better research and development of chitosan-modified magnetic biochar.
    Matched MeSH terms: Chitosan*
  15. Fong SS, Foo YY, Saw WS, Leo BF, Teo YY, Chung I, et al.
    Int J Nanomedicine, 2022;17:137-150.
    PMID: 35046650 DOI: 10.2147/IJN.S337093
    Purpose: The use of nanocarriers to improve the delivery and efficacy of antimetastatic agents is less explored when compared to cytotoxic agents. This study reports the entrapment of an antimetastatic Signal Transducer and Activator of Transcription 3 (STAT3) dimerization blocker, Stattic (S) into a chitosan-coated-poly(lactic-co-glycolic acid) (C-PLGA) nanocarrier and the improvement on the drug's physicochemical, in vitro and in vivo antimetastatic properties post entrapment.

    Methods: In vitro, physicochemical properties of the Stattic-entrapped C-PLGA nanoparticles (S@C-PLGA) and Stattic-entrapped PLGA nanoparticles (S@PLGA, control) in terms of size, zeta potential, polydispersity index, drug loading, entrapment efficiency, Stattic release in different medium and cytotoxicity were firstly evaluated. The in vitro antimigration properties of the nanoparticles on breast cancer cell lines were then studied by Scratch assay and Transwell assay. Study on the in vivo antitumor efficacy and antimetastatic properties of S@C-PLGA compared to Stattic were then performed on 4T1 tumor bearing mice.

    Results: The S@C-PLGA nanoparticles (141.8 ± 2.3 nm) was hemocompatible and exhibited low Stattic release (12%) in plasma. S@C-PLGA also exhibited enhanced in vitro anti-cell migration potency (by >10-fold in MDA-MB-231 and 5-fold in 4T1 cells) and in vivo tumor growth suppression (by 33.6%) in 4T1 murine metastatic mammary tumor bearing mice when compared to that of the Stattic-treated group. Interestingly, the number of lung and liver metastatic foci was found to reduce by 50% and 56.6%, respectively, and the average size of the lung metastatic foci was reduced by 75.4% in 4T1 tumor-bearing mice treated with S@C-PLGA compared to Stattic-treated group (p < 0.001).

    Conclusion: These findings suggest the usage of C-PLGA nanocarrier to improve the delivery and efficacy of antimetastatic agents, such as Stattic, in cancer therapy.

    Matched MeSH terms: Chitosan*
  16. Pant A, Negi JS
    Eur J Pharm Sci, 2018 Jan 15;112:180-185.
    PMID: 29191520 DOI: 10.1016/j.ejps.2017.11.020
    The aim of this study was to develop a novel controlled ionic gelation strategy for chitosan nanoparticle preparation to avoid particle aggregation tendency associated with conventional ionic gelation process. In this study inclusion complexation behaviour of sodium tripolyphosphate (TPP) with beta cyclodextrin (β-CD) has been investigated. The TPP-β-CD inclusion complex was characterized by FT-IR, XRD and DSC techniques. The complexation behaviour was also investigated by molecular docking study. The results showed that the TPP molecule formed inclusion complex with β-CD. Further, TPP-β-CD inclusion complex was used to prepare chitosan nanoparticles. The chitosan nanoparticles based on TPP-β-CD inclusion complex had smaller size of 104.2nm±0.608, good PDI value of 0.346±0.016 and acceptable zeta potential of +27.33mV±0.416. The surface characteristics of chitosan nanoparticles were also observed with transmission electron microscopy. Results indicates that TPP-β-CD inclusion complex can be used for the formation of chitosan nanoparticles with smaller and more uniform particle size in comparison to conventional TPP based chitosan nanoparticles.
    Matched MeSH terms: Chitosan/chemistry*
  17. Mohamed Hatta NS, Lau SW, Chua HB, Takeo M, Sen TK, Mubarak NM, et al.
    Environ Res, 2023 May 01;224:115527.
    PMID: 36822539 DOI: 10.1016/j.envres.2023.115527
    Bacterial strains belonging to Citrobacter spp. were reported to produce polysaccharides consisting of N-acetylglucosamine and glucosamine like chitosan, with high flocculation activity. In this work, the flocculation dewatering performance of activated sludge conditioned by a novel cationic chitosan-like bioflocculant (BF) named BF01314, produced from Citrobacter youngae GTC 01314, was evaluated under the influences of flocculant dosage, pH, and temperature. At BF dosage as low as 0.5 kg/t DS, the sludge dewaterability was significantly enhanced in comparison to the raw (untreated) sludge, featuring well-flocculated characteristic (reduction in CST from 22.0 s to 9.4 s) and good sludge filterability with reduced resistance (reduction in SRF by one order from 7.42 × 1011 to 9.59 × 1010 m/kg) and increased compactness of sludge (increase in CSC from 15.2 to 23.2%). Besides, the BF demonstrated comparable high sludge dewatering performance within the pH range between 2 and 8, and temperature range between 25 °C and 80 °C. Comparison between the BF, the pristine chitosan and the commercial cationic copolymer MF 7861 demonstrated equivalent performance with enhanced dewaterability at the dosage between 2.0 and 3.0 kg/t DS. Besides, the BF demonstrated strong flocculation activity (>99%) when added to the sludge suspension using moderate to high flocculation speeds (100-200 rpm) with at least 3-min mixing time. The BF's reaction in sludge flocculation was best fitted with a pseudo first-order kinetic model. Electrostatic charge patching and polymer bridging mechanisms are believed to be the dominant mechanistic phenomena during the BF's sludge conditioning process (coagulation-flocculation).
    Matched MeSH terms: Chitosan*
  18. Wu R, Abdulhameed AS, Jawad AH, Yong SK, Li H, ALOthman ZA, et al.
    Int J Biol Macromol, 2023 Dec 01;252:126342.
    PMID: 37591432 DOI: 10.1016/j.ijbiomac.2023.126342
    Herein, the polymer nanomatrix of chitosan/SiO2 (CHI/n-SiO2) was enriched with a π-π electron donor-acceptor system using diaromatic rings of benzil (BEZ) assisted via a hydrothermal process to obtain an effective adsorbent of chitosan-benzil/SiO2 (CHI-BEZ/n-SiO2). The polymer nanomatrix (CHI/n-SiO2) and the resulting adsorbent (CHI-BEZ/n-SiO2) were applied to remove the anionic acid red 88 (AR88) dye from aqueous media in a comparative mode. Box-Behnken design (BBD) was adopted to optimize AR88 adsorption onto CHI/n-SiO2 and CHI-BEZ/n-SiO2 with respect to variables that influence AR88 adsorption (adsorbent dose: 0.02-0.1 g/100 mL; pH: 4-10; and time: 10-90). The adsorption studies at equilibrium were conducted with a variety of initial AR88 dye concentrations (20-200 mg/L). The adsorption isotherm results reveal that the AR88 adsorption by CHI/n-SiO2 and CHI-BEZ/n-SiO2 are described by the Langmuir model. The kinetic adsorption profiles of AR88 with CHI/n-SiO2 and CHI-BEZ/n-SiO2 reveal that the pseudo-first-order model provides the best fit results. Interestingly, CHI-BEZ/n-SiO2 has a high adsorption capacity (261.2 mg/g), which exceeds the adsorption capacity of CHI/n-SiO2 (215.1 mg/g) that relates to the surface effects of SiO2 and the functionalization of chitosan with BEZ. These findings show that CHI-BEZ/n-SiO2 represents a highly efficient adsorbent for the removal of harmful pollutants from water, which outperforming the CHI/n-SiO2 system.
    Matched MeSH terms: Chitosan*
  19. Azelee NIW, Dahiya D, Ayothiraman S, Noor NM, Rasid ZIA, Ramli ANM, et al.
    Int J Biol Macromol, 2023 Dec 31;253(Pt 2):126492.
    PMID: 37634772 DOI: 10.1016/j.ijbiomac.2023.126492
    The unscientific disposal of the most abundant crustacean wastes, especially those derived from marine sources, affects both the economy and the environment. Strategic waste collection and management is the need of the hour. Sustainable valorization approaches have played a crucial role in solving those issues as well as generating wealth from waste. The shellfishery wastes are rich in valuable bioactive compounds such as chitin, chitosan, minerals, carotenoids, lipids, and other amino acid derivatives. These value-added components possessed pleiotropic applications in different sectors viz., food, nutraceutical, cosmeceutical, agro-industrial, healthcare, and pharmaceutical sectors. The manuscript covers the recent status, scope of shellfishery management, and different bioactive compounds obtained from crustacean wastes. In addition, both sustainable and conventional routes of valorization approaches were discussed with their merits and demerits along with their combinations. The utilization of nano and microtechnology was also included in the discussion, as they have become prominent research areas in recent years. More importantly, the future perspectives of crustacean waste management and other potential valorization approaches that can be implemented on a large scale.
    Matched MeSH terms: Chitosan*
  20. Saheed IO, Yusof ENM, Oh WD, Hanafiah MAKM, Suah FBM
    Int J Biol Macromol, 2023 Jul 01;242(Pt 2):124798.
    PMID: 37178882 DOI: 10.1016/j.ijbiomac.2023.124798
    Adsorption efficiency of a duo-material blend featuring the fabrication of modified chitosan adsorbents (powder (C-emimAc), bead (CB-emimAc) and sponge (CS-emimAc)) for the removal of Cd(II) from aqueous solution was investigated. The chitosan@activated carbon (Ch/AC) blend was developed in a green ionic solvent, 1-ethyl-3-methyl imidazolium acetate (EmimAc) and its characteristics was examined using FTIR, SEM, EDX, BET and TGA. The possible mechanism of interaction between the composites and Cd(II) was also predicted using the density functional theory (DFT) analysis. The interactions of various blend forms (C-emimAc, CB-emimAc and CS-emimAc) with Cd(II) gave better adsorption at pH 6. The composites also present excellent chemical stability in both acidic and basic conditions. The monolayer adsorption capacities obtained (under the condition 20 mg/L [Cd], adsorbent dosage 5 mg, contact time 1 h) for the CB-emimAc (84.75 mg/g) > C-emimAc (72.99 mg/g) > CS-emimAc (55.25 mg/g), as this was supported by their order of increasing BET surface area (CB-emimAc (120.1 m2/g) > C-emimAc (67.4 m2/g) > CS-emimAc (35.3 m2/g)). The feasible adsorption interactions between Cd(II) and Ch/AC occurs through the O-H and N-H groups of the composites, as supported by DFT analysis in which an electrostatic interactions was predicted as the dominant force. The interaction energy (-1309.35 eV) calculated via DFT shows that the Ch/AC with amino (-NH) and hydroxyl (-OH) groups are more effective with four significant electrostatic interactions with the Cd(II) ion. The various form of Ch/AC composites developed in EmimAc possess good adsorption capacity and stability for the adsorption Cd(II).
    Matched MeSH terms: Chitosan*
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