Displaying publications 221 - 240 of 276 in total

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  1. Stigmasterol: An adjuvant for beta lactam antibiotics against beta-lactamase positive clinical isolates
    Yenn TW, Arslan Khan M, Amiera Syuhada N, Chean Ring L, Ibrahim D, Tan WN
    Steroids, 2017 Dec;128:68-71.
    PMID: 29104098 DOI: 10.1016/j.steroids.2017.10.016
    The emergence of beta lactamase producing bacterial strains eliminated the use of beta lactam antibiotics as chemotherapeutic alternative. Beta lactam antibiotics can be coupled with non-antibiotic adjuvants to combat these multidrug resistant strains. We study the synergistic antibiotic effect of stigmasterol as adjuvant of ampicillin against clinical isolates. Ampicillin was used in this study as a beta lactam antibiotic model. All test bacteria were beta lactamase producing clinical isolates. The combination showed significantly better antibiotic activity on all bacteria tested. The two test substances have synergistic antibiotic activity, and the effect was observed in both Gram positive and Gram negative bacteria. The synergistic antibiotic effect of stigmasterol and ampicillin was evident by the low fractional inhibitory concentration (FIC) index on Checkerboard Assay. The results suggest that the combination of ampicillin and stigmasterol acts additively in the treatment of infections caused by beta-lactamase producing pathogens. In bacterial growth reduction assay, ampicillin and stigmasterol alone exhibited very weak inhibitory effect on the bacterial growth, relative to ethanol control. Comparatively, combination of stigmasterol-ampicillin greatly reduced the colony counts at least by 98.7%. In conclusion, we found synergistic effects of stigmasterol and ampicillin against beta lactamase producing clinical isolates. This finding is important as it shows potential application of stigmasterol as an antibiotic adjuvant.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  2. New anti-bacterial halogenated tricyclic sesquiterpenes from Bornean Laurencia majuscula (Harvey) Lucas
    Kamada T, Phan CS, Vairappan CS
    Nat Prod Res, 2019 Feb;33(4):464-471.
    PMID: 29092618 DOI: 10.1080/14786419.2017.1396593
    Three new halogenated tricyclic sesquiterpenes, omphalaurediol (1), rhodolaurenones B (2) and C (3) were isolated together with nine known haloganated sesquiterpenes such as rhodolaurenone A (4), rhodolaureol (5), isorhodolaureol (6), (-)-laurencenone D (7), elatol (8), (+)-deschloroelatol (9), cartilagineol (10), (+)-laurencenone B (11) and 2-chloro-3-hydroxy-α-chamigren-9-one (12) from a population of Bornean red algae Laurencia majuscula. The structures of three new metabolites were determined based on their spectroscopic data (IR, 1D and 2D NMR, and MS). These compounds showed antibacterial activity against three human pathogenic bacteria (Escherichia coli, Salmonella typhi and Vibrio cholera).
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  3. Identification of α-tocopherol as a bioactive component of Dicranopteris linearis with disrupting property against preformed biofilm of Staphylococcus aureus
    Mawang CI, Lim YY, Ong KS, Muhamad A, Lee SM
    J Appl Microbiol, 2017 Nov;123(5):1148-1159.
    PMID: 28869803 DOI: 10.1111/jam.13578
    AIMS: The potential of Dicranopteris linearis leaves' extract and its bioactive components were investigated for the first time for its disrupting ability against Staphylococcus aureus biofilms.

    METHODS AND RESULTS: The leaves of D. linearis were subjected to sonication-assisted extraction using hexane (HEX), dichloromethane, ethyl acetate and methanol (MeOH). It was found that only the MeOH fraction exhibited antimicrobial activity using broth microdilution assay; while all four fractions do not exhibit biofilm inhibition activity against S. aureusATCC 6538P, S. aureusATCC 43300, S. aureusATCC 33591 and S. aureusATCC 29213 using crystal violet assay. Among the four fractions tested, only the HEX fraction showed biofilm disrupting ability, with 60-90% disruption activity at 5 mg ml-1against all four S. aureus strains tested. Bioassay-guided purification of the active fraction has led to the isolation of α-tocopherol. α-Tocopherol does not affect the cells within the biofilms but instead affects the biofilm matrix in order to disrupt S. aureus biofilms.

    CONCLUSIONS: α-Tocopherol was identified to be the bioactive component of D. linearis with disruption activity against S. aureus biofilm matrix.

    SIGNIFICANCE AND IMPACT OF THE STUDY: The use of α-tocopherol as a biofilm disruptive agent might potentially be useful to treat biofilm-associated infections in the future.

    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  4. Pluronic-F127 composite film loaded with erythromycin for wound application: formulation, physicomechanical and in vitro evaluations
    Alavi T, Rezvanian M, Ahmad N, Mohamad N, Ng SF
    Drug Deliv Transl Res, 2019 04;9(2):508-519.
    PMID: 29181832 DOI: 10.1007/s13346-017-0450-z
    Composite film dressings composed of pluronic F127 (PL)-pectin (PC) and pluronic (PL) F127-gelatin (GL) were investigated as potential drug delivery system for wound healing. Composite films were solvent cast by blending PL with PC or GL in different ratios using glycerol (2.5%) as plasticizer. Erythromycin (ER) (0.1%) was incorporated in films as model hydrophobic antibiotic. The optimized composite films were characterized for physical appearance, morphology, mechanical profile, and thermal behavior. In addition, drug release, antibacterial activity, and cytocompatibility of the films were investigated to assess their potential as drug delivery system. The composite films exhibited excellent wound dressing characters in terms of appearance, stability, and mechanical profile. Moreover, ER-loaded composite films released ER in controlled manner, exhibited antibacterial activity against Staphylococcus aureus, and were non-toxic to human skin fibroblast. These findings demonstrate that these composite films hold the potential to be formulated as antibacterial wound dressing.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  5. Green synthesis of anisotropic zinc oxide nanoparticles with antibacterial and cytofriendly properties
    Saravanan M, Gopinath V, Chaurasia MK, Syed A, Ameen F, Purushothaman N
    Microb Pathog, 2018 Feb;115:57-63.
    PMID: 29248514 DOI: 10.1016/j.micpath.2017.12.039
    Zinc oxide nanoparticles (ZnONPs) exhibit abundant biomedical applications. Anisotropic ZnONPs with a defined shape and size were synthesized using Bacillus megaterium (NCIM 2326) cell free extract as a bio-reductant. The study investigated the multidimensional effect of ZnONPs on Helicobacter pylori strains and assessed its biosafety in normal human mesenchymal stem cells (hMSc). The highly stable ZnONPs were produced using B. megaterium and Zinc nitrate as a precursor. The phase of ZnONPs formation and structural characterization were performed by UV- visible (UV-Vis), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Field Emission Scanning electron microscopy (FESEM) analysis. Furthermore, the ZnONPs exhibited higher biocompatibility against human mesenchymal stem cells (hMSC) and proved to be potentially safe in mammalian cells. Corroborating the current investigation, we described the anti-H. Pylori dosage of ZnONPs was safe to hMSC and could efficiently use as nano-antibiotic.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  6. Exploring Promising Immunomodulatory Potential of Natural and Synthetic 1,3-Diphenyl-2-propen-1-one Analogs: A Review of Mechanistic Insight
    Safdar MH, Hasan H, Afzal S, Hussain Z
    Mini Rev Med Chem, 2018;18(12):1047-1063.
    PMID: 29173165 DOI: 10.2174/1389557517666171123212039
    The immune system is an intricate and coordinated nexus serving as a natural defense to preclude internal and external pathogenic insults. The deregulation in the natural balance of immunological functions as a consequence of either over expression or under expression of immune cells tends to cause disruption of homeostasis in the body and may lead to development of numerous immune system disorders. Chalcone moieties (1,3-diphenyl-2-propen-1-one) have been well-documented as ideal lead compounds or precursors to design a wide range of pharmacologically active agents to down-regulate various immune disorders. Owing to their unique structural and molecular framework, these α, β-unsaturated carbonyl-based moieties have also gained remarkable recognition due to their other multifarious pharmacological properties including antifungal, anti-inflammatory, anti-malarial, antibacterial, anti-tuberculosis, and anticancer potential. Though a great number of methodologies are currently being employed for their synthesis, this review mainly focuses on the natural and synthetic chalcone derivatives that are exclusively synthesized via Claisen-Schmidt condensation reaction and their immunomodulatory prospects. We have critically reviewed the literature and provided convincing evidence for the promising efficacy of chalcone derivatives to modulate functioning of various innate and adaptive immune players including granulocytes, mast cells, monocytes, macrophages, platelets, dendritic cells, natural killer cells, and T-lymphocytes.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  7. Chemical constituents and medical benefits of Plantago major
    Adom MB, Taher M, Mutalabisin MF, Amri MS, Abdul Kudos MB, Wan Sulaiman MWA, et al.
    Biomed Pharmacother, 2017 Dec;96:348-360.
    PMID: 29028587 DOI: 10.1016/j.biopha.2017.09.152
    The medicinal benefits of Plantago major have been acknowledged around the world for hundreds of years. This plant contains a number of effective chemical constituents including flavonoids, alkaloids, terpenoids, phenolic acid derivatives, iridoid glycosides, fatty acids, polysaccharides and vitamins which contribute to its exerting specific therapeutic effects. Correspondingly, studies have found that Plantago major is effective as a wound healer, as well as an antiulcerative, antidiabetic, antidiarrhoeal, anti-inflammatory, antinociceptive, antibacterial, and antiviral agent. It also combats fatigue and cancer, is an antioxidant and a free radical scavenger. This paper provides a review of the medicinal benefits and chemical constituents of Plantago major published in journals from year 1937 to 2015 which are available from PubMed, ScienceDirect and Google Scholar.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  8. Investigation on solution-to-gel characteristic of thermosensitive and mucoadhesive biopolymers for the development of moxifloxacin-loaded sustained release periodontal in situ gels
    Sheshala R, Quah SY, Tan GC, Meka VS, Jnanendrappa N, Sahu PS
    Drug Deliv Transl Res, 2019 04;9(2):434-443.
    PMID: 29392681 DOI: 10.1007/s13346-018-0488-6
    The objectives of present research were to develop and characterize thermosensitive and mucoadhesive polymer-based sustained release moxifloxacin in situ gels for the treatment of periodontal diseases. Poloxamer- and chitosan-based in situ gels are in liquid form at room temperature and transform into gel once administered into periodontal pocket due to raise in temperature to 37 °C. Besides solution-to-gel characteristic of polymers, their mucoadhesive nature aids the gel to adhere to mucosa in periodontal pocket for prolonged time and releases the drug in sustained manner. These formulations were prepared using cold method and evaluated for pH, solution-gel temperature, syringeability and viscosity. In vitro drug release studies were conducted using dialysis membrane at 37 °C and 50 rpm. Antimicrobial studies carried out against Aggregatibacter actinomycetemcomitans (A.A.) and Streptococcus mutans (S. Mutans) using agar cup-plate method. The prepared formulations were clear and pH was at 7.01-7.40. The viscosity of formulations was found to be satisfactory. Among the all, formulations comprising of 21% poloxamer 407 and 2% poloxamer 188 (P5) and in combination with 0.5% HPMC (P6) as well as 2% chitosan and 70% β-glycerophosphate (C6) demonstrated an ideal gelation temperature (33-37 °C) and sustained the drug release for 8 h. Formulations P6 and C6 showed promising antimicrobial efficacy with zone of inhibition of 27 mm for A.A. and 55 mm for S. Mutans. The developed sustained release in situ gel formulations could enhance patient's compliance by reducing the dosing frequency and also act as an alternative treatment to curb periodontitis.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  9. Fulltext Experimental and molecular modeling approach to optimize suitable polymers for fabrication of stable fluticasone nanoparticles with enhanced dissolution and antimicrobial activity
    Ahmed S, Govender T, Khan I, Rehman NU, Ali W, Shah SMH, et al.
    Drug Des Devel Ther, 2018;12:255-269.
    PMID: 29440875 DOI: 10.2147/DDDT.S148912
    Background and aim: The challenges with current antimicrobial drug therapy and resistance remain a significant global health threat. Nanodrug delivery systems are playing a crucial role in overcoming these challenges and open new avenues for effective antimicrobial therapy. While fluticasone (FLU), a poorly water-soluble corticosteroid, has been reported to have potential antimicrobial activity, approaches to optimize its dissolution profile and antimicrobial activity are lacking in the literature. This study aimed to combine an experimental study with molecular modeling to design stable FLU nanopolymeric particles with enhanced dissolution rates and antimicrobial activity.

    Methods: Six different polymers were used to prepare FLU nanopolymeric particles: hydroxyl propyl methylcellulose (HPMC), poly (vinylpyrrolidone) (PVP), poly (vinyl alcohol) (PVA), ethyl cellulose (EC), Eudragit (EUD), and Pluronics®. A low-energy method, nanoprecipitation, was used to prepare the polymeric nanoparticles.

    Results and conclusion: The combination of HPMC-PVP and EUD-PVP was found most effective to produce stable FLU nanoparticles, with particle sizes of 250 nm ±2.0 and 280 nm ±4.2 and polydispersity indices of 0.15 nm ±0.01 and 0.25 nm ±0.03, respectively. The molecular modeling studies endorsed the same results, showing highest polymer drug binding free energies for HPMC-PVP-FLU (-35.22 kcal/mol ±0.79) and EUD-PVP-FLU (-25.17 kcal/mol ±1.12). In addition, it was observed that Ethocel® favored a wrapping mechanism around the drug molecules rather than a linear conformation that was witnessed for other individual polymers. The stability studies conducted for 90 days demonstrated that HPMC-PVP-FLU nanoparticles stored at 2°C-8°C and 25°C were more stable. Crystallinity of the processed FLU nanoparticles was confirmed using differential scanning calorimetry, powder X-ray diffraction analysis and TEM. The Fourier transform infrared spectroscopy (FTIR) studies showed that there was no chemical interaction between the drug and chosen polymer system. The HPMC-PVP-FLU nanoparticles also showed enhanced dissolution rate (P<0.05) compared to the unprocessed counterpart. The in vitro antibacterial studies showed that HPMC-PVP-FLU nanoparticles displayed superior effect against gram-positive bacteria compared to the unprocessed FLU and positive control.

    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  10. Capgermacrenes D-G, new sesquiterpenoids from a Bornean soft coral, Capnella imbricata
    Phan CS, Vairappan CS
    Nat Prod Res, 2017 Apr;31(7):742-748.
    PMID: 27750446 DOI: 10.1080/14786419.2016.1241997
    Four new bicyclogermacrenes, capgermacrenes D (1) E (2) F (3) and G (4) were isolated from a population of Bornean soft coral Capnella imbricata. The structures of these metabolites were elucidated based on their nuclear magnetic resonance and high-resolution electrospray ionisation mass spectrometry spectral data. These compounds showed bacteriastatic and bacteriacidal activities against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  11. Synthesis and characterization of nitrile functionalized silver(I)-N-heterocyclic carbene complexes: DNA binding, cleavage studies, antibacterial properties and mosquitocidal activity against the dengue vector, Aedes albopictus
    Asekunowo PO, Haque RA, Razali MR, Avicor SW, Wajidi MFF
    Eur J Med Chem, 2018 Apr 25;150:601-615.
    PMID: 29550733 DOI: 10.1016/j.ejmech.2018.03.029
    A series of four benzimidazolium based nitrile-functionalized mononuclear-Ag(I)-N-heterocyclic carbene and binuclear-Ag(I)-N-heterocyclic carbene (Ag(I)-NHC) hexafluorophosphate complexes (5b-8b) were synthesized by reacting the corresponding hexafluorophosphate salts (1b-4b) with Ag2O in acetonitrile, respectively. These compounds were characterized by 1H NMR, 13C NMR, IR, UV-visible spectroscopic techniques, elemental analyses and molar conductivity. Additionally, 8b was structurally characterized by single crystal X-ray diffraction technique. Preliminary in vitro antibacterial evaluation was conducted for all the compounds against two standard bacteria; gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacterial strains. Most of the Ag(I)-NHC complexes (5b-8b) showed moderate to good antibacterial activity with MIC values in the range of 12.5-100 μg/mL. Especially, compound 8b exhibited promising anti-Staphylococcus aureus activity with a low MIC value (12.5 μg/mL). However, all the hexafluorophosphate salts (1b-4b) were inactive against the bacteria strains. The preliminary interactive investigation revealed that the most active compound, 8b, could effectively intercalate into DNA to form 8b-DNA complex which shows a better binding ability for DNA (Kb = 3.627 × 106) than the complexes 5b-7b (2.177 × 106, 8.672 × 105 and 6.665 × 105, respectively). Nuclease activity of the complexes on plasmid DNA and Aedes albopictus genomic DNA was time-dependent, although minimal. The complexes were larvicidal to the mosquito, with 5b, 6b and 8b being highly active. Developmental progression from the larval to the adult stage was affected by the complexes, progressively being toxic to the insect's development with increasing concentration. These indicate the potential use of these complexes as control agents against bacteria and the dengue mosquito Ae. albopictus.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  12. Fulltext Aporphine alkaloids from the leaves of Phoebe grandis (Nees) Mer. (Lauraceae) and their cytotoxic and antibacterial activities
    Omar H, Hashim NM, Zajmi A, Nordin N, Abdelwahab SI, Azizan AH, et al.
    Molecules, 2013 Jul 29;18(8):8994-9009.
    PMID: 23899833 DOI: 10.3390/molecules18088994
    The oxoaporphine alkaloid lysicamine (1), and three proaporphine alkaloids, litsericinone (2), 8,9,11,12-tetrahydromecambrine (3) and hexahydromecambrine A (4) were isolated from the leaves of Phoebe grandis (Nees) Merr. (Lauraceae). Compounds 2 and 3 were first time isolated as new naturally occurring compounds from plants. The NMR data for the compounds 2-4 have never been reported so far. Compounds 1 and 2 showed significant cytotoxic activity against a MCF7 (human estrogen receptor (ER+) positive breast cancer) cell line with IC₅₀ values of 26 and 60 µg/mL, respectively. Furthermore, in vitro cytotoxic activity against HepG2 (human liver cancer) cell line was evaluated for compounds 1-4 with IC₅₀ values of 27, 14, 81 and 20 µg/mL, respectively. Lysicamine (1) displayed strong antibacterial activity against Bacillus subtilis (B145), Staphylococcus aureus (S1434) and Staphylococus epidermidis (a clinically isolated strain) with inhibition zones of 15.50 ± 0.57, 13.33 ± 0.57 and 12.00 ± 0.00 mm, respectively. However, none of the tested pathogenic bacteria were susceptible towards compounds 2 and 3.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  13. Fulltext Effect of Cadmium and Copper Exposure on Growth, Secondary Metabolites and Antioxidant Activity in the Medicinal Plant Sambung Nyawa (Gynura procumbens (Lour.) Merr)
    Ibrahim MH, Chee Kong Y, Mohd Zain NA
    Molecules, 2017 Oct 12;22(10).
    PMID: 29023367 DOI: 10.3390/molecules22101623
    A randomized complete block (RCBD) study was designed to investigate the effects of cadmium (Cd) and copper (Cu) on the growth, bioaccumulation of the two heavy metals, metabolite content and antibacterial activities in Gyanura procumbens (Lour.) Merr. Nine treatments including (1) control (no Cd and Cu); (2) Cd 2 = cadmium 2 mg/L; (3) Cd 4 = cadmium 4 mg/L; (4) Cu 70 = copper 70 mg/L; (5) Cu 140 = copper 140 mg/L); (6) Cd 2 + Cu 70 = cadmium 2 mg/L + copper 70 mg/L); (7) Cd 2 + Cu 140 = cadmium 2 mg/L + copper 70 mg/L); (8) Cd 4 + Cu 70 = cadmium 4 mg/L+ copper 70 mg/L and (9) Cd 4 + Cu 140 = cadmium 4 mg/L + copper 140 mg/L) were evaluated in this experiment. It was found that the growth parameters (plant dry weight, total leaf area and basal diameter) were reduced with the exposure to increased concentrations of Cd and Cu and further decreased under interaction between Cd and Cu. Production of total phenolics, flavonoids and saponin was observed to be reduced under combined Cd and Cu treatment. The reduction in the production of plant secondary metabolites might be due to lower phenyl alanine lyase (PAL) activity under these conditions. Due to that, the 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant potential (FRAP) and antibacterial activities was also found to be reduced by the combined treatments. The current experiments show that the medicinal properties of G. procumbens are reduced by cadmium and copper contamination. The accumulation of heavy metal also was found to be higher than the safety level recommended by the WHO in the single and combined treatments of Cd and Cu. These results indicate that exposure of G. procumbens to Cd and Cu contaminated soil may potentially harm consumers due to bioaccumulation of metals and reduced efficacy of the herbal product.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  14. Fulltext Regioselective Sequential Modification of Chitosan via Azide-Alkyne Click Reaction: Synthesis, Characterization, and Antimicrobial Activity of Chitosan Derivatives and Nanoparticles
    Sarwar A, Katas H, Samsudin SN, Zin NM
    PLoS One, 2015;10(4):e0123084.
    PMID: 25928293 DOI: 10.1371/journal.pone.0123084
    Recently, the attention of researchers has been drawn toward the synthesis of chitosan derivatives and their nanoparticles with enhanced antimicrobial activities. In this study, chitosan derivatives with different azides and alkyne groups were synthesized using click chemistry, and these were further transformed into nanoparticles by using the ionotropic gelation method. A series of chitosan derivatives was successfully synthesized by regioselective modification of chitosan via an azide-alkyne click reaction. The amino moieties of chitosan were protected during derivatization by pthaloylation and subsequently unblocked at the end to restore their functionality. Nanoparticles of synthesized derivatives were fabricated by ionic gelation to form complexes of polyanionic penta-sodium tripolyphosphate (TPP) and cationic chitosan derivatives. Particle size analysis showed that nanoparticle size ranged from 181.03 ± 12.73 nm to 236.50 ± 14.32 nm and had narrow polydispersity index and positive surface charge. The derivatives and corresponding nanoparticles were evaluated in vitro for antibacterial and antifungal activities against three gram-positive and gram-negative bacteria and three fungal strains, respectively. The minimum inhibitory concentration (MIC) of all derivatives ranged from 31.3 to 250 µg/mL for bacteria and 188 to1500 µg/mL for fungi and was lower than that of native chitosan. The nanoparticles with MIC ranging from 1.56 to 25 µg/mLfor bacteria and 94 to 750 µg/mL for fungi exhibited higher activity than the chitosan derivatives. Chitosan O-(1-methylbenzene) triazolyl carbamate and chitosan O-(1-methyl phenyl sulfide) triazolyl carbamate were the most active against the tested bacterial and fungal strains. The hemolytic assay on erythrocytes and cell viability test on two different cell lines (Chinese hamster lung fibroblast cells V79 and Human hepatic cell line WRL68) demonstrated the safety; suggesting that these derivatives could be used in future medical applications. Chitosan derivatives with triazole functionality, synthesized by Huisgen 1,3-dipolar cycloaddition, and their nanoparticles showed significant enhancement in antibacterial and antifungal activities in comparison to those associated with native, non-altered chitosan.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  15. Fulltext Down-top nanofabrication of binary (CdO)x (ZnO)1-x nanoparticles and their antibacterial activity
    Al-Hada NM, Mohamed Kamari H, Abdullah CAC, Saion E, Shaari AH, Talib ZA, et al.
    Int J Nanomedicine, 2017;12:8309-8323.
    PMID: 29200844 DOI: 10.2147/IJN.S150405
    In the present study, binary oxide (cadmium oxide [CdO])x (zinc oxide [ZnO])1-x nanoparticles (NPs) at different concentrations of precursor in calcination temperature were prepared using thermal treatment technique. Cadmium and zinc nitrates (source of cadmium and zinc) with polyvinylpyrrolidone (capping agent) have been used to prepare (CdO)x (ZnO)1-x NPs samples. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray (EDX), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. XRD patterns analysis revealed that NPs were formed after calcination, which showed a cubic and hexagonal crystalline structure of (CdO)x (ZnO)1-x NPs. The phase analysis using EDX spectroscopy and FTIR spectroscopy confirmed the presence of Cd and Zn as the original compounds of prepared (CdO)x (ZnO)1-x NP samples. The average particle size of the samples increased from 14 to 33 nm as the concentration of precursor increased from x=0.20 to x=0.80, as observed by TEM results. The surface composition and valance state of the prepared product NPs were determined by X-ray photoelectron spectroscopy (XPS) analyses. Diffuse UV-visible reflectance spectra were used to determine the optical band gap through the Kubelka-Munk equation; the energy band gap was found to decrease for CdO from 2.92 to 2.82 eV and for ZnO from 3.22 to 3.11 eV with increasing x value. Additionally, photoluminescence (PL) spectra revealed that the intensity in PL increased with an increase in particle size. In addition, the antibacterial activity of binary oxide NP was carried out in vitro against Escherichia coli ATCC 25922 Gram (-ve), Salmonella choleraesuis ATCC 10708, and Bacillus subtilis UPMC 1175 Gram (+ve). This study indicated that the zone of inhibition of 21 mm has good antibacterial activity toward the Gram-positive B. subtilis UPMC 1175.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  16. Fulltext Aluminosilicate Nanocomposites from Incinerated Chinese Holy Joss Fly Ash: A Potential Nanocarrier for Drug Cargos
    Ramanathan S, Gopinath SCB, Md Arshad MK, Poopalan P, Anbu P, Lakshmipriya T
    Sci Rep, 2020 Feb 25;10(1):3351.
    PMID: 32099019 DOI: 10.1038/s41598-020-60208-x
    An incredible amount of joss fly ash is produced from the burning of Chinese holy joss paper; thus, an excellent method of recycling joss fly ash waste to extract aluminosilicate nanocomposites is explored. The present research aims to introduce a novel method to recycle joss fly ash through a simple and straightforward experimental procedure involving acidic and alkaline treatments. The synthesized aluminosilicate nanocomposite was characterized to justify its structural and physiochemical characteristics. A morphological analysis was performed with field-emission transmission electron microscopy, and scanning electron microscopy revealed the size of the aluminosilicate nanocomposite to be ~25 nm, while also confirming a uniformly spherical-shaped nanostructure. The elemental composition was measured by energy dispersive spectroscopy and revealed the Si to Al ratio to be 13.24 to 7.96, showing the high purity of the extracted nanocomposite. The roughness and particle distribution were analyzed using atomic force microscopy and a zeta analysis. X-ray diffraction patterns showed a synthesis of faceted and cubic aluminosilicate crystals in the nanocomposites. The presence of silica and aluminum was further proven by X-ray photoelectron spectroscopy, and the functional groups were recognized through Fourier transform infrared spectroscopy. The thermal capacity of the nanocomposite was examined by a thermogravimetric analysis. In addition, the research suggested the promising application of aluminosilicate nanocomposites as drug carriers. The above was justified by an enzyme-linked apta-sorbent assay, which claimed that the limit of the aptasensing aluminosilicate-conjugated ampicillin was two-fold higher than that in the absence of the nanocomposite. The drug delivery property was further justified through an antibacterial analysis against Escherichia coli (gram-negative) and Bacillus subtilis (gram-positive).
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  17. Fulltext Facile Synthesis and Characterization of Palm CNF-ZnO Nanocomposites with Antibacterial and Reinforcing Properties
    Supramaniam J, Low DYS, Wong SK, Tan LTH, Leo BF, Goh BH, et al.
    Int J Mol Sci, 2021 May 28;22(11).
    PMID: 34071337 DOI: 10.3390/ijms22115781
    Cellulose nanofibers (CNF) isolated from plant biomass have attracted considerable interests in polymer engineering. The limitations associated with CNF-based nanocomposites are often linked to the time-consuming preparation methods and lack of desired surface functionalities. Herein, we demonstrate the feasibility of preparing a multifunctional CNF-zinc oxide (CNF-ZnO) nanocomposite with dual antibacterial and reinforcing properties via a facile and efficient ultrasound route. We characterized and examined the antibacterial and mechanical reinforcement performances of our ultrasonically induced nanocomposite. Based on our electron microscopy analyses, the ZnO deposited onto the nanofibrous network had a flake-like morphology with particle sizes ranging between 21 to 34 nm. pH levels between 8-10 led to the formation of ultrafine ZnO particles with a uniform size distribution. The resultant CNF-ZnO composite showed improved thermal stability compared to pure CNF. The composite showed potent inhibitory activities against Gram-positive (methicillin-resistant Staphylococcus aureus (MRSA)) and Gram-negative Salmonella typhi (S. typhi) bacteria. A CNF-ZnO-reinforced natural rubber (NR/CNF-ZnO) composite film, which was produced via latex mixing and casting methods, exhibited up to 42% improvement in tensile strength compared with the neat NR. The findings of this study suggest that ultrasonically-synthesized palm CNF-ZnO nanocomposites could find potential applications in the biomedical field and in the development of high strength rubber composites.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  18. Fulltext Compositions and antimicrobial properties of binary ZnO-CuO nanocomposites encapsulated calcium and carbon from Calotropis gigantea targeted for skin pathogens
    Govindasamy GA, Mydin RBSMN, Sreekantan S, Harun NH
    Sci Rep, 2021 01 08;11(1):99.
    PMID: 33420110 DOI: 10.1038/s41598-020-79547-w
    Calotropis gigantea (C. gigantea) extract with an ecofriendly nanotechnology approach could provide promising antimicrobial activity against skin pathogens. This study investigates the antimicrobial capability of green synthesized binary ZnO-CuO nanocomposites from C. gigantea against non-MDR (Staphylococcus aureus and Escherichia coli) and MDR (Klebsiella pneumoniae, Pseudomonas aeruginosa and methicillin-resistant S. aureus) skin pathogens. Scanning electron microscopy and transmission electron microscopy revealed the size and shape of B3Z1C sample. Results of X-ray powder diffraction, energy-dispersive spectroscopy, FTIR and UV-Vis spectroscopy analyses confirmed the presence of mixed nanoparticles (i.e., zinc oxide, copper oxide, carbon and calcium) and the stabilising phytochemical agents of plant (i.e., phenol and carbonyl). Antimicrobial results showed that carbon and calcium decorated binary ZnO-CuO nanocomposites with compositions of 75 wt% of ZnO and 25 wt% CuO (B3Z1C) was a strong bactericidal agent with the MBC/MIC ratio of ≤ 4 and ≤ 2 for non-MDR and MDR pathogens, respectively. A significant non-MDR zone of inhibitions were observed for BZC by Kirby-Bauer disc-diffusion test. Further time-kill observation revealed significant fourfold reduction in non-MDR pathogen viable count after 12 h study period. Further molecular studies are needed to explain the biocidal mechanism underlying B3Z1C potential.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry*
  19. Fulltext Autoclave-assisted synthesis of AgNPs in Z. officinale extract and assessment of their cytotoxicity, antibacterial and antioxidant activities
    Kalantari K, Afifi AM, Moniri M, Moghaddam AB, Kalantari A, Izadiyan Z
    IET Nanobiotechnol, 2019 May;13(3):262-268.
    PMID: 31053688 DOI: 10.1049/iet-nbt.2018.5066
    In this study, the authors synthesised silver nanoparticles (AgNPs) using autoclave as a simple, unique and eco-friendly approach. The effect of Zingiber officinale extract was evaluated as a reducing and stabiliser agent. According to transmission electron microscopy results, the AgNPs were in the spherical shape with a particle size of ∼17 nm. The biomedical properties of AgNPs as antibacterial agents and free radical scavenging activity were estimated. Synthesised AgNPs showed significant 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging. Strong bactericidal activity was shown by the AgNPs on Gram-positive and Gram-negative bacteria. A maximum inhibition zone of ∼14 mm was obtained for epidermidis at a concentration of 60 μg/ml for sample fabricated at 24 h. The AgNPs also showed a significant cytotoxic effect against MCF-7 breast cancer cell lines with an half maximal inhibitory concentration value of 62 μg/ml in 24 h by the MTT assay. It could be concluded that Z. officinale extract can be used effectively in the production of potential antioxidant and antimicrobial AgNPs for commercial application.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
  20. Fulltext Surfactant-mediated synthesis of polyhydroxybutyrate (PHB) nanoparticles for sustained drug delivery
    Pachiyappan S, Shanmuganatham Selvanantham D, Kuppa SS, Chandrasekaran S, Samrot AV
    IET Nanobiotechnol, 2019 Jun;13(4):416-427.
    PMID: 31171747 DOI: 10.1049/iet-nbt.2018.5053
    In this study, polyhydroxybutyrate (PHB) nanoparticles were synthesised following nanoprecipitation method having different solvents and surfactant (Tween 80) concentrations. In this study, PHB nanoparticles were encapsulated with curcumin and subjected for sustained curcumin delivery. Both the curcumin loaded and unloaded PHB nanoparticles were characterised using FTIR, SEM, and AFM. Sizes of the particles were found to be between 60 and 300 nm. The drug encapsulation efficiency and in vitro drug release of the nanoparticles were analysed. Antibacterial activity and anticancer activity were also evaluated. The LC50 values of most of the nanoparticles were found to be between 10 and 20 µg/100 µl, anticancer activity of curcumin loaded PHB nanoparticles were further confirmed by AO/PI staining and mitochondrial depolarisation assay.
    Matched MeSH terms: Anti-Bacterial Agents/chemistry
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