Displaying publications 61 - 80 of 154 in total

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  1. Khanmirzaei MH, Ramesh S, Ramesh K
    J Nanosci Nanotechnol, 2020 Apr 01;20(4):2423-2429.
    PMID: 31492257 DOI: 10.1166/jnn.2020.17192
    Solid polymer electrolytes (SPEs) were prepared using rice starch as the polymer, sodium iodide (NaI) as the salt and 1-hexyl-3-methylimidazolium iodide (HMII) as the ionic liquid (IL). The solution casting technique was used for preparation of the PEs. The ionic conductivity and temperaturedependent properties of the PEs were measured and all the SPEs were found to follow the Arrhenius thermal activated model. Ionic conductivity increased as the percentage of ILs increased. The SPE containing 20% (wt) of HMII IL showed the highest ionic conductivity of 1.83×10-3 S/cm. Spectral and structural characterization of the PEs were performed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicate that the decomposition temperature (Tdc), glass transition temperatures (Tg) and melting points (Tm) shifted when complexation with HMII occurred. The PEs were used to fabricate dye-sensitized solar cells (DSSCs) and the DSSCs were analyzed under a 1-sun simulator. The SPE with the highest ionic conductivity displayed a short circuit current density (Jsc) of 9.07 (mA cm-2), open circuit voltage (Voc) of 0.58 (V), a fill factor (FF) of 0.65 and had the highest energy conversion efficiency of 3.42%.
    Matched MeSH terms: Thermogravimetry
  2. Adzmi F, Meon S, Musa MH, Yusuf NA
    J Microencapsul, 2012;29(3):205-10.
    PMID: 22309479 DOI: 10.3109/02652048.2012.659286
    Microencapsulation is a process by which tiny parcels of an active ingredient are packaged within a second material for the purpose of shielding the active ingredient from the surrounding environment. This study aims to determine the ability of the microencapsulation technique to improve the viability of Trichoderma harzianum UPM40 originally isolated from healthy groundnut roots as effective biological control agents (BCAs). Alginate was used as the carrier for controlled release, and montmorillonite clay (MMT) served as the filler. The encapsulated Ca-alginate-MMT beads were characterised using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The FTIR results showed the interaction between the functional groups of alginate and MMT in the Ca-alginate-MMT beads. Peaks at 1595, 1420 and 1020 cm(-1) characterised alginate, and peaks at 1028 and 453 cm(-1) characterised MMT; both sets of peaks appeared in the Ca-alginate-MMT FTIR spectrum. The TGA analysis showed an improvement in the thermal stability of the Ca-alginate-MMT beads compared with the alginate beads alone. SEM analysis revealed a homogeneous distribution of the MMT particles throughout the alginate matrix. T. harzianum UPM40 was successfully encapsulated in the Ca-alginate-MMT beads. Storage analysis of the encapsulated T. harzianum UPM40 showed that the low storage temperature of 5°C resulted in significantly (p 
    Matched MeSH terms: Thermogravimetry/methods
  3. Mishra RK, Ramasamy K, Lim SM, Ismail MF, Majeed AB
    J Mater Sci Mater Med, 2014 Aug;25(8):1925-39.
    PMID: 24831081 DOI: 10.1007/s10856-014-5228-y
    The present study investigates the development of methyl cellulose (MC)-sodium alginate (SA)-montmorillonite (MMT) clay based bionanocomposite films with interesting wound healing properties. The differential scanning calorimetry analysis of the composite films revealed presence of single glass transition temperature (Tg) confirming the miscible nature of the ternary blended films. The increase in MMT ratio in the composite films reduced the mobility of biopolymer chains (MC/SA) which increased the Tg of the film. Thermogravimetric analysis showed that dispersion of clay (MMT) at nano level significantly delayed the weight loss that correlated with higher thermal stability of the composite films. It was observed that the developed films were able to exhibit antimicrobial activity against four typical pathogenic bacteria found in the presence of wound. The developed films were able to significantly inhibit (10 mg/ml) the growth of Enterococcus faecium and Pseudomonas aeruginosa. In vitro scratch assay indicated potential wound closure activities of MC-2-4 bionanocomposite films at their respective highest subtoxic doses. In conclusion, these ternary bionanocomposite films were found to be promising systems for wound healing applications.
    Matched MeSH terms: Thermogravimetry
  4. Azwar E, Chan DJC, Kasan NA, Rastegari H, Yang Y, Sonne C, et al.
    J Hazard Mater, 2022 02 15;424(Pt A):127329.
    PMID: 34601414 DOI: 10.1016/j.jhazmat.2021.127329
    Aquatic weeds pose hazards to aquatic ecosystems and particularly the aquatic environment in shellfish aquaculture due to its excessive growth covering entire freshwater bodies, leading to environmental pollution particularly eutrophication intensification, water quality depletion and aquatic organism fatality. In this study, pyrolysis of six aquatic weed types (wild and cultured species of Salvinia sp., Lemna sp. and Spirodella sp.) were investigated to evaluate its potential to reduce and convert the weeds into value-added chemicals. The aquatic weeds demonstrated high fixed carbon (8.7-47.3 wt%), volatile matter content (39.0-76.9 wt%), H/C ratio (1.5-2.0) and higher heating value (6.6-18.8 MJ/kg), representing desirable physicochemical properties for conversion into biofuels. Kinetic analysis via Coats-Redfern integral method obtained different orders for chemical reaction mechanisms (n = 1, 1.5, 2, 3), activation energy (55.94-209.41 kJ/mol) and pre-exponential factor (4.08 × 104-4.20 × 1017 s-1) at different reaction zones (zone 1: 150-268 °C, zone 2: 268-409 °C, zone 3: 409-600 °C). The results provide useful information for design and optimization of the pyrolysis reactor and establishment of the process condition to dispose this environmentally harmful species.
    Matched MeSH terms: Thermogravimetry
  5. Farah Nadia O, Xiang LY, Lie LY, Chairil Anuar D, Mohd Afandi MP, Azhari Baharuddin S
    J Environ Sci (China), 2015 Feb 1;28:81-94.
    PMID: 25662242 DOI: 10.1016/j.jes.2014.07.023
    Co-composting of poultry manure and rubber wood sawdust was performed with the ratio of 2:1 (V/V) for a period of 60 days. An investigation was carried out to study the extracellular enzymatic activities and structural degradation utilizing Fourier transform infrared spectroscopy (FT-IR), thermogravimetry and differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The microbial succession was also determined by using denaturing gel gradient electrophoresis (DGGE). The compost was able to reach its highest temperature of 71°C at day 3 and stabilized between 30 and 40°C for 8 weeks. CMCase, FPase and β-glucosidase acted synergistically in order to degrade the cellulosic substrate. The xylanase activities increased gradually during the composting and reached the peak value of 11.637 U/g on day 35, followed by a sharp decline. Both LiP and MnP activities reached their peak values on day 35 with 0.431 and 0.132 U/g respectively. The FT-IR spectra revealed an increase in aromaticity and a decrease in aliphatic compounds such as carbohydrates as decomposition proceeded. TGA/DTG data exhibited significant changes in weight loss in compost samples, indicating degradation of organic matter. SEM micrographs showed higher amounts of parenchyma exposed on the surface of rubber wood sawdust at day 60, showing significant degradation. DGGE and 16S rDNA analyses showed that Burkholderia sp., Pandoraea sp., and Pseudomonas sp. were present throughout the composting process. Ornithinibacillus sp. and Castellaniella ginsengisoli were only found in the initial stage of the composting, while different strains of Burkholderia sp. also occurred in the later stage of composting.
    Matched MeSH terms: Thermogravimetry
  6. Abdullah EA, Abdullah AH, Zainal Z, Hussein MZ, Ban TK
    J Environ Sci (China), 2012;24(10):1876-84.
    PMID: 23520859
    A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents. The synthesized product was characterized by different analytical techniques. The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants. Different kinetic, isotherm and diffusion models were chosen to describe the adsorption process. X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however, the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes. Dyes removal was found to be a function of adsorbent dosage, initial dye concentration, solution pH and temperature. The reduction of Langmuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent. Mass transfer can be described by intra-particle diffusion at a certain stage, but it was not the rate limiting step that controlled the adsorption process. Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.
    Matched MeSH terms: Thermogravimetry
  7. Kalidasan B, Pandey AK, Aljafari B, Chinnasamy S, Kareri T, Rahman S
    J Environ Manage, 2023 Dec 15;348:119439.
    PMID: 37890400 DOI: 10.1016/j.jenvman.2023.119439
    Metal, carbon and conducting polymer nanoparticles are blended with organic phase change materials (PCMs) to enhance the thermal conductivity, heat storage ability, thermal stability and optical property. However, the existing nanoparticle are expensive and need to be handle with high caution during operation as well during disposal owing to its toxicity. Subsequently handling of solid waste and the disposal of organic PCM after longevity usage are of utmost concern and are less exposed. Henceforth, the current research presents a new dimension of exploration by green synthesized nanoparticles from a thorny shrub of an invasive weed named Prosopis Juliflora (PJ) which is a agro based solid waste. Subsequently, the research is indented to decide the concentration of green synthesized nanoparticle for effective heat transfer rate of organic PCM (Tm = 35-40 °C & Hm = 145 J/g). Furthermore, an in-depth understanding on the kinetic and thermodynamic profile of degradation mechanism involved in disposal of PCM after usage via Coats and Redfern technique is exhibited. Engaging a two-step method, we fuse the green synthesized nanomaterial with PCM to obtain nanocomposite PCM. On experimental evaluation, thermal conductivity of the developed nanocomposite (PCM + PJ) increases by 63.8% (0.282 W/m⋅K to 0.462 W/m⋅K) with 0.8 wt% green synthesized nanomaterial owing to the uniform distribution of nanoparticle within PCM matrix thereby contributing to bridging thermal networks. Subsequently, PCM and PCM + PJ nanocomposites are tested using thermogravimetric analyzer at different heating rates (05 °C/min; 10 °C/min; 15 °C/min & 20 °C/min) to analyze the decomposition kinetic reaction. The kinetic and thermodynamic profile of degradation mechanism involved in disposal of PCM and its nanocomposite of PCM + PJ provides insight on thermal parameters to be considered on large scale operation and to understand the complex nature of the chemical reactions. Adopting thirteen different chemical mechanism model under Coats and Redfern method we determine the reaction mechanism; kinetic parameter like activation energy (Ea) & pre-exponential factor (A) and thermodynamic parameter like change in enthalpy (ΔH), change in Gibbs free energy (ΔG) and change in entropy (ΔS). Dispersion of PJ nanomaterial with PCM reduces Ea from 370.82 kJ/mol-1 to 342.54 kJ/mol-1 (7.7% reduction), as the developed nanomaterial is enriched in carbon element and exhibits a catalytic effect for breakdown reaction. Corresponding, value of ΔG for PCM and PCM + PJ sample within heating rates of 05-20 °C/min varies between 168.95 and 41.611 kJ/mol-1. The current research will unbolt new works with focus on exploring the pyrolysis behaviour of phase change materials and its nanocomposite used for energy storage applications. This work also provides insights on the disposal of PCM which is an organic solid waste. The thermo-kinetic profile will help to investigate and predict the optimum heating rate and temperature range for conversion of micro-scale pyrolysis to commercial scale process.
    Matched MeSH terms: Thermogravimetry
  8. Abd Manan FM, Attan N, Zakaria Z, Mahat NA, Abdul Wahab R
    J Biotechnol, 2018 May 28;280:19-30.
    PMID: 29852195 DOI: 10.1016/j.jbiotec.2018.05.015
    To overcome drawbacks in the conventional chemical route to synthesize eugenyl benzoate, immobilized Rhizomucor miehei lipase (RML) as the biocatalyst was proposed. The RML conjugated to a hybrid support consisting of biopolymers, chitosan (CS) and chitin nanowhiskers (CNWs). 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDAC) was used as the crosslinker to bind the lipase. Immobilization of RML was the highest on crosslinked CS/CNWs which gave a protein loading of ∼8.12 mg/g, corresponding to specific and residual activity of 537 U/g and 137%, respectively. Fourier transform infrared spectroscopy, thermogravimetric analysis-differential thermogravimetry, field emission scanning electron and atomic force microscopy of RML-CS/CNWs revealed that RML was successfully attached to the surface of crosslinked CS/CNWs. Under an optimized condition, the highest yield of eugenyl benzoate (56.3%) was attained after 5 h using 3 mg/mL of RML-CS/CNWs with molar ratio of eugenol: benzoic acid of 3:1, as compared to only 47.3% for the free RML. Analyses of FTIR and NMR on purified eugenyl benzoate affirmed that the ester was successfully produced in the enzymatic esterification. Therefore, the use of the RML-CS/CNWs biocatalysts appears promising to afford good yields of eugenyl benzoate within a relatively shorter reaction time.
    Matched MeSH terms: Thermogravimetry
  9. Mohd Warikh Abd Rashid, Hutagalung, Sabar Derita, Zainal Arifin Ahmad
    MyJurnal
    A study on the effect of the modify values of x in CaCu3-xMn4+xO12 system has been carried out with x = 0.1, 0.3, 0.5, 0.7 and 0.9. The materials were prepared via solid-state reaction. The preparation conditions have been optimized using thermogravimetry analysis (TGA) technique. Material formations under the reported conditions have been confirmed by X-ray diffraction (XRD) studies. The results show that the formation of CaCu3Mn4O12 started at calcinations temperature of 600 0 C with the presence of raw material and was formed completely at 850 0 C. Field emission scanning electron microscopy (FESEM) analysis indicated that the increase of x value in the composition had changed the microstructures to be more faceted. The impedance spectrum is characterized by the appearance of two semicircle arcs whose pattern of evolution changes with rise of values x in the CaCu3-xMn4+xMn4O12 system. Bulk resistance (Rb) and grain boundary resistance (Rgb) of CaCu3- xMn4+xO12 decreases form 824.24 : to 98.68 : and 418.18 : to 2.20 : respectively, with the increasing of x value.
    Matched MeSH terms: Thermogravimetry
  10. Selvakumaran S, Muhamad II
    Int J Pharm, 2015 Dec 30;496(2):323-31.
    PMID: 26453788 DOI: 10.1016/j.ijpharm.2015.10.005
    Genipin, a natural and non-toxic cross linker, was used to prepare cross linked floating kappa carrageenan/sodium carboxymethyl cellulose hydrogels and the effect of genipin on hydrogels characterization was investigated. Calcium carbonates were employed as gas forming agents. Ranitidine hydrochloride was used as drug. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were carried out to study the changes in the characteristics of hydrogels. Furthermore, scanning electron microscope (SEM) was performed to study microstructure of hydrogels. The result showed that all formulated hydrogels had excellent floating behavior. It was discovered that the cross linking reaction showed significant effect on gel strength, porosity and swelling ratio compared to non-cross linked hydrogels. It was found that the drug release was slower and lesser after being cross linked. Microstructure study shows that cross linked hydrogels exhibited hard and rough surface. Therefore, genipin can be an interesting cross linking agent for controlled drug delivery in gastrointestinal tract.
    Matched MeSH terms: Thermogravimetry
  11. Hasan S, Al Ali H, Al-Qubaisi M, Zobir Hussein M, Ismail M, Zainal Z, et al.
    Int J Nanomedicine, 2012;7:3351-63.
    PMID: 22848164 DOI: 10.2147/IJN.S30809
    A controlled-release formulation of an antihistamine, cetirizine, was synthesized using zinc-layered hydroxide as the host and cetirizine as the guest. The resulting well-ordered nanolayered structure, a cetirizine nanocomposite "CETN," had a basal spacing of 33.9 Å, averaged from six harmonics observed from X-ray diffraction. The guest, cetirizine, was arranged in a horizontal bilayer between the zinc-layered hydroxide (ZLH) inorganic interlayers. Fourier transform infrared spectroscopy studies indicated that the intercalation takes place without major change in the structure of the guest and that the thermal stability of the guest in the nanocomposites is markedly enhanced. The loading of the guest in the nanocomposites was estimated to be about 49.4% (w/w). The release study showed that about 96% of the guest could be released in 80 hours by phosphate buffer solution at pH 7.4 compared with about 97% in 73 hours at pH 4.8. It was found that release was governed by pseudo-second order kinetics. Release of histamine from rat basophilic leukemia cells was found to be more sensitive to the intercalated cetirizine in the CETN compared with its free counterpart, with inhibition of 56% and 29%, respectively, at 62.5 ng/mL. The cytotoxicity assay toward Chang liver cells line show the IC₅₀ for CETN and ZLH are 617 and 670 μg/mL, respectively.
    Matched MeSH terms: Thermogravimetry
  12. Chang BY, Huang NM, An'amt MN, Marlinda AR, Norazriena Y, Muhamad MR, et al.
    Int J Nanomedicine, 2012;7:3379-87.
    PMID: 22848166 DOI: 10.2147/IJN.S28189
    A simple single-stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide/titanium dioxide nanocomposites. The titanium dioxide nanoparticles are formed at the same time as the graphene oxide is reduced to graphene. The triethanolamine used in the process has two roles. It acts as a reducing agent for the graphene oxide as well as a capping agent, allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (~20 nm). Transmission electron micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide nanosheet. Thermogravimetric analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential applications for this technology were demonstrated by the use of a reduced graphene oxide/titanium dioxide nanocomposite-modified glassy carbon electrode, which enhanced the electrochemical performance compared to a conventional glassy carbon electrode when interacting with mercury(II) ions in potassium chloride electrolyte.
    Matched MeSH terms: Thermogravimetry
  13. Kalani M, Yunus R, Abdullah N
    Int J Nanomedicine, 2011;6:1101-5.
    PMID: 21698077 DOI: 10.2147/IJN.S18979
    The aim of this study was to optimize the different process parameters including pressure, temperature, and polymer concentration, to produce fine small spherical particles with a narrow particle size distribution using a supercritical antisolvent method for drug encapsulation. The interaction between different process parameters was also investigated.
    Matched MeSH terms: Thermogravimetry
  14. Hussein MZ, Al Ali SH, Zainal Z, Hakim MN
    Int J Nanomedicine, 2011;6:1373-83.
    PMID: 21796241 DOI: 10.2147/IJN.S21567
    An ellagic acid (EA)-zinc layered hydroxide (ZLH) nanohybrid (EAN) was synthesized under a nonaqueous environment using EA and zinc oxide (ZnO) as the precursors. Powder X-ray diffraction showed that the basal spacing of the nanohybrid was 10.4 Å, resulting in the spatial orientation of EA molecules between the interlayers of 22.5° from z-axis with two negative charges at 8,8' position of the molecules pointed toward the ZLH interlayers. FTIR study showed that the intercalated EA spectral feature is generally similar to that of EA, but with bands slightly shifted. This indicates that some chemical bonding of EA presence between the nanohybrid interlayers was slightly changed, due to the formation of host-guest interaction. The nanohybrid is of mesopores type with 58.8% drug loading and enhanced thermal stability. The release of the drug active, EA from the nanohybrid was found to be sustained and therefore has good potential to be used as a drug controlled-release formulation. In vitro bioassay study showed that the EAN has a mild effect on the hepatocytes cells, similar to its counterpart, free EA.
    Matched MeSH terms: Thermogravimetry
  15. Hussein Al Ali SH, Al-Qubaisi M, Hussein MZ, Zainal Z, Hakim MN
    Int J Nanomedicine, 2011;6:3099-111.
    PMID: 22163163 DOI: 10.2147/IJN.S24510
    A new simple preparation method for a hippurate-intercalated zinc-layered hydroxide (ZLH) nanohybrid has been established, which does not need an anion-exchange procedure to intercalate the hippurate anion into ZLH interlayers.
    Matched MeSH terms: Thermogravimetry
  16. Samrot AV, Kudaiyappan T, Bisyarah U, Mirarmandi A, Faradjeva E, Abubakar A, et al.
    Int J Nanomedicine, 2020;15:7097-7115.
    PMID: 33061370 DOI: 10.2147/IJN.S259653
    Background: Plant gums consist of polysaccharides which can be used in the preparation of nanocarriers and provide a wide application in pharmaceutical applications including as drug delivery agents and the matrices for drug release. The objectives of the study were to collect plant gums from Araucaria heterophylla L and Prosopis chilensis L and to extract and characterize their polysaccharides. Then to utilize these plant gum-derived polysaccharides for the formulation of nanocarriers to use for drug loading and to examine their purpose in drug delivery in vitro.

    Methods: Plant gum was collected, polysaccharide was extracted, purified, characterized using UV-Vis, FTIR, TGA and GCMS and subjected to various bioactive studies. The purified polysaccharide was used for making curcumin-loaded nanocarriers using STMP (sodium trimetaphosphate). Bioactivities were performed on the crude, purified and drug-loaded nanocarriers. These polysaccharide-based nanocarriers were characterized using UV-Vis spectrophotometer, FTIR, SEM, and AFM. Drug release kinetics were performed for the drug-loaded nanocarriers.

    Results: The presence of glucose, xylose and sucrose was studied from the UV-Vis and GCMS analysis. Purified polysaccharides of both the plants showed antioxidant activity and also antibacterial activity against Bacillus sp. Purified polysaccharides were used for nanocarrier synthesis, where the size and shape of the nanocarriers were studied using SEM analysis and AFM analysis. The size of the drug-loaded nanocarriers was found to be around 200 nm. The curcumin-loaded nanocarriers were releasing curcumin slow and steady.

    Conclusion: The extracted pure polysaccharide of A. heterophylla and P. chilensis acted as good antioxidants and showed antibacterial activity against Bacillus sp. These polysaccharides were fabricated into curcumin-loaded nanocarriers whose size was below 200 nm. Both the drug-loaded nanocarriers synthesized using A. heterophylla and P. chilensis showed antibacterial activity with a steady drug release profile. Hence, these natural exudates can serve as biodegradable nanocarriers in drug delivery.

    Matched MeSH terms: Thermogravimetry
  17. Qi J, Zhang H, Wang Y, Mani MP, Jaganathan SK
    Int J Nanomedicine, 2018;13:2777-2788.
    PMID: 29785105 DOI: 10.2147/IJN.S151242
    Introduction: Currently, the design of extracellular matrix (ECM) with nanoscale properties in bone tissue engineering is challenging. For bone tissue engineering, the ECM must have certain properties such as being nontoxic, highly porous, and should not cause foreign body reactions.

    Materials and methods: In this study, the hybrid scaffold based on polyvinyl alcohol (PVA) blended with metallocene polyethylene (mPE) and plectranthus amboinicus (PA) was fabricated for bone tissue engineering via electrospinning. The fabricated hybrid nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform and infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurement, and atomic force microscopy (AFM). Furthermore, activated partial thromboplastin time (APTT), prothrombin time (PT), and hemolytic assays were used to investigate the blood compatibility of the prepared hybrid nanocomposites.

    Results: The prepared hybrid nanocomposites showed reduced fiber diameter (238±45 nm) and also increased porosity (87%) with decreased pore diameter (340±86 nm) compared with pure PVA. The interactions between PVA, mPE, and PA were identified by the formation of the additional peaks as revealed in FTIR. Furthermore, the prepared hybrid nanocomposites showed a decreased contact angle of 51°±1.32° indicating a hydrophilic nature and exhibited lower thermal stability compared to pristine PVA. Moreover, the mechanical results revealed that the electrospun scaffold showed an improved tensile strength of 3.55±0.29 MPa compared with the pristine PVA (1.8±0.52 MPa). The prepared hybrid nanocomposites showed delayed blood clotting as noted in APTT and PT assays indicating better blood compatibility. Moreover, the hemolysis assay revealed that the hybrid nanocomposites exhibited a low hemolytic index of 0.6% compared with pure PVA, which was 1.6% suggesting the safety of the developed nanocomposite to red blood cells (RBCs).

    Conclusion: The prepared nanocomposites exhibited better physico-chemical properties, sufficient porosity, mechanical strength, and blood compatibility, which favors it as a valuable candidate in bone tissue engineering for repairing the bone defects.

    Matched MeSH terms: Thermogravimetry
  18. Jiang H, Mani MP, Jaganathan SK
    Int J Nanomedicine, 2019;14:8149-8159.
    PMID: 31632024 DOI: 10.2147/IJN.S214646
    Introduction: Recently several new approaches were emerging in bone tissue engineering to develop a substitute for remodelling the damaged tissue. In order to resemble the native extracellular matrix (ECM) of the human tissue, the bone scaffolds must possess necessary requirements like large surface area, interconnected pores and sufficient mechanical strength.

    Materials and methods: A novel bone scaffold has been developed using polyurethane (PE) added with wintergreen (WG) and titanium dioxide (TiO2). The developed nanocomposites were characterized through field emission scanning electron microscopy (FESEM), Fourier transform and infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle measurement, thermogravimetric analysis (TGA), atomic force microscopy (AFM) and tensile testing. Furthermore, anticoagulant assays, cell viability analysis and calcium deposition were used to investigate the biological properties of the prepared hybrid nanocomposites.

    Results: FESEM depicted the reduced fibre diameter for the electrospun PE/WG and PE/WG/TiO2 than the pristine PE. The addition of WG and TiO2 resulted in the alteration in peak intensity of PE as revealed in the FTIR. Wettability measurements showed the PE/WG showed decreased wettability and the PE/WG/TiO2 exhibited improved wettability than the pristine PE. TGA measurements showed the improved thermal behaviour for the PE with the addition of WG and TiO2. Surface analysis indicated that the composite has a smoother surface rather than the pristine PE. Further, the incorporation of WG and TiO2 improved the anticoagulant nature of the pristine PE. In vitro cytotoxicity assay has been performed using fibroblast cells which revealed that the electrospun composites showed good cell attachment and proliferation after 5 days. Moreover, the bone apatite formation study revealed the enhanced deposition of calcium content in the fabricated composites than the pristine PE.

    Conclusion: Fabricated nanocomposites rendered improved physico-chemical properties, biocompatibility and calcium deposition which are conducive for bone tissue engineering.

    Matched MeSH terms: Thermogravimetry
  19. Barahuie F, Dorniani D, Saifullah B, Gothai S, Hussein MZ, Pandurangan AK, et al.
    Int J Nanomedicine, 2017;12:2361-2372.
    PMID: 28392693 DOI: 10.2147/IJN.S126245
    Chitosan (CS) iron oxide magnetic nanoparticles (MNPs) were coated with phytic acid (PTA) to form phytic acid-chitosan-iron oxide nanocomposite (PTA-CS-MNP). The obtained nanocomposite and nanocarrier were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and thermogravimetric and differential thermogravimetric analyses. Fourier transform infrared spectra and thermal analysis of MNPs and PTA-CS-MNP nanocomposite confirmed the binding of CS on the surface of MNPs and the loading of PTA in the PTA-CS-MNP nanocomposite. The coating process enhanced the thermal stability of the anticancer nanocomposite obtained. X-ray diffraction results showed that the MNPs and PTA-CS-MNP nanocomposite are pure magnetite. Drug loading was estimated using ultraviolet-visible spectroscopy and showing a 12.9% in the designed nanocomposite. Magnetization curves demonstrated that the synthesized MNPs and nanocomposite were superparamagnetic with saturation magnetizations of 53.25 emu/g and 42.15 emu/g, respectively. The release study showed that around 86% and 93% of PTA from PTA-CS-MNP nanocomposite could be released within 127 and 56 hours by a phosphate buffer solution at pH 7.4 and 4.8, respectively, in a sustained manner and governed by pseudo-second order kinetic model. The cytotoxicity of the compounds on HT-29 colon cancer cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The HT-29 cell line was more sensitive against PTA-CS-MNP nanocomposite than PTA alone. No cytotoxic effect was observed on normal cells (3T3 fibroblast cells). This result indicates that PTA-CS-MNP nanocomposite can inhibit the proliferation of colon cancer cells without causing any harm to normal cell.
    Matched MeSH terms: Thermogravimetry
  20. Yusefi M, Shameli K, Jahangirian H, Teow SY, Umakoshi H, Saleh B, et al.
    Int J Nanomedicine, 2020;15:5417-5432.
    PMID: 32801697 DOI: 10.2147/IJN.S250047
    INTRODUCTION: Green-based materials have been increasingly studied to circumvent off-target cytotoxicity and other side-effects from conventional chemotherapy.

    MATERIALS AND METHODS: Here, cellulose fibers (CF) were isolated from rice straw (RS) waste by using an eco-friendly alkali treatment. The CF network served as an anticancer drug carrier for 5-fluorouracil (5-FU). The physicochemical and thermal properties of CF, pure 5-FU drug, and the 5-FU-loaded CF (CF/5-FU) samples were evaluated. The samples were assessed for in vitro cytotoxicity assays using human colorectal cancer (HCT116) and normal (CCD112) cell lines, along with human nasopharyngeal cancer (HONE-1) and normal (NP 460) cell lines after 72-hours of treatment.

    RESULTS: XRD and FTIR revealed the successful alkali treatment of RS to isolate CF with high purity and crystallinity. Compared to RS, the alkali-treated CF showed an almost fourfold increase in surface area and zeta potential of up to -33.61 mV. SEM images illustrated the CF network with a rod-shaped structure and comprised of ordered aggregated cellulose. TGA results proved that the thermal stability of 5-FU increased within the drug carrier. Based on UV-spectroscopy measurements for 5-FU loading into CF, drug loading encapsulation efficiency was estimated to be 83 ±0.8%. The release media at pH 7.4 and pH 1.2 showed a maximum drug release of 79% and 46%, respectively, over 24 hours. In cytotoxicity assays, CF showed almost no damage, while pure 5-FU killed most of the both normal and cancer cells. Impressively, the drug-loaded sample of CF/5-FU at a 250 µg/mL concentration demonstrated a 58% inhibition against colorectal cancer cells, but only a 23% inhibition against normal colorectal cells. Further, a 62.50 µg/mL concentration of CF/5FU eliminated 71% and 39% of nasopharyngeal carcinoma and normal nasopharyngeal cells, respectively.

    DISCUSSION: This study, therefore, showed the strong potential anticancer activity of the novel CF/5-FU formulations, warranting their further investigation.

    Matched MeSH terms: Thermogravimetry
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