@article { ISI:000336442600003, title = {Rapid efficient synthesis and characterization of silver, gold, and bimetallic nanoparticles from the medicinal plant plumbago zeylanica and their application in biofilm control}, journal = {International Journal of Nanomedicine}, volume = {9}, year = {2014}, month = {MAY}, pages = {2635-2653}, publisher = {DOVE MEDICAL PRESS LTD}, address = {PO BOX 300-008, ALBANY, AUCKLAND 0752, NEW ZEALAND}, abstract = {

Background: Nanoparticles (NPs) have gained significance in medical fields due to their high surface-area-to-volume ratio. In this study, we synthesized NPs from a medicinally important plant - Plumbago zeylanica. Materials and methods: Aqueous root extract of P. zeylanica (PZRE) was analyzed for the presence of flavonoids, sugars, and organic acids using high-performance thin-layer chromatography (HPTLC), gas chromatography-time of flight-mass spectrometry (GC-TOF-MS), and biochemical methods. The silver NPs (AgNPs), gold NPs (AuNPs), and bimetallic NPs (AgAuNPs) were synthesized from root extract and characterized using ultraviolet-visible spectra, X-ray diffraction (XRD), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The effects of these NPs on Acinetobacter baumannii, Staphylococcus aureus, and Escherichia coli biofilms were studied using quantitative biofilm inhibition and disruption assays, as well as using fluorescence, scanning electron microscopy, and atomic force microscopy. Results: PZRE showed the presence of phenolics, such as plumbagin, and flavonoids, in addition to citric acid, sucrose, glucose, fructose, and starch, using HPTLC, GC-TOF-MS, and quantitative analysis. Bioreduction of silver nitrate (AgNO3) and chloroauric acid (HAuCl4) were confirmed at absorbances of 440 nm (AgNPs), 570 nm (AuNPs), and 540 nm (AgAuNPs), respectively. The maximum rate of synthesis at 50 degrees C was achieved with 5 mM AgNO3 within 4.5 hours for AgNPs; and with 0.7 mM HAuCl4 within 5 hours for AuNPs. The synthesis of AgAuNPs, which completed within 90 minutes with 0.7 mM AgNO3 and HAuCl4, was found to be the fastest. Fourier-transform infrared spectroscopy confirmed bioreduction, while EDS and XRD patterns confirmed purity and the crystalline nature of the NPs, respectively. TEM micrographs and DLS showed about 60 nm monodispersed Ag nanospheres, 20-30 nm Au nanospheres adhering to form Au nanotriangles, and about 90 nm hexagonal blunt-ended AgAuNPs. These NPs also showed antimicrobial and antibiofilm activity against E. coli, A. baumannii, S. aureus, and a mixed culture of A. baumannii and S. aureus. AgNPs inhibited biofilm in the range of 96\%-99\% and AgAuNPs from 93\% to 98\% in single-culture biofilms. AuNPs also showed biofilm inhibition, with the highest of 98\% in S. aureus. AgNPs also showed good biofilm disruption, with the highest of 88\% in A. baumannii. Conclusion: This is the first report on rapid and efficient synthesis of AgNPs, AuNPs and AgAuNPs from P. zeylanica and their effect on quantitative inhibition and disruption of bacterial biofilms.

}, keywords = {AgAuNPs, AgNPs, AuNPs, biofilm inhibition and disruption, GC-TOF-MS, P. zeylanica}, issn = {1178-2013}, doi = {10.2147/IJN.S59834}, author = {Salunke, Gayatri R. and Ghosh, Sougata and Kumar, R. J. Santosh and Khade, Samiksha and Vashisth, Priya and Kale, Trupti S. and Chopade, Snehal and Pruthi, Vikas and Kundu, Gopal and Bellare, Jayesh R. and Chopade, Balu Ananda} } @article { ISI:000360705500008, title = {Chemical and biological metal nanoparticles as antimycobacterial agents: a comparative study}, journal = {International Journal of Antimicrobial Agents}, volume = {46}, number = {2}, year = {2015}, month = {AUG}, pages = {183-188}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Resistance among mycobacteria leading to multidrug-resistant and extensively drug-resistant tuberculosis is a major threat. However, nanotechnology has provided new insights in drug delivery and medicine development. This is the first comparative report to determine the activity of chemically and biologically synthesised silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) against mycobacteria. Screening data revealed the high mycobactericidal efficiency of AgNPs, with minimum inhibitory concentrations (MICs) of \<3 mu g/mL, whereas no such activity was exhibited by AuNPs at concentrations up to 100 mu g/mL. Moreover, in vitro and ex vivo THP-1 infection model assays showed greater efficacy of chemical AgNPs compared with biogenic AgNPs to inhibit active and dormant stage mycobacterial growth. Up to 40\% cytotoxicity against human cell lines was observed at a AgNP concentration of 10 x MIC (30 mu g/mL) after 48 h. AgNPs were shown to have more specificity towards mycobacteria than towards other Gram-negative and Gram-positive pathogenic bacteria. The selectivity index was found to be in the range of 11-23, indicating the potential of these nanoparticles for use in developing new therapeutics for tuberculosis. (C) 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

}, keywords = {Antibiotic resistance, Antimycobacterial agent, Cytotoxicity, Mycobacteria, Nanoparticles, tuberculosis}, issn = {0924-8579}, doi = {10.1016/j.ijantimicag.2015.03.014}, author = {Singh, Richa and Nawale, Laxman U. and Arkile, Manisha A. and Shedbalkar, Utkarsha U. and Wadhwani, Sweety A. and Sarkar, Dhiman and Chopade, Balu Ananda} } @article { ISI:000355856200084, title = {Synthesis, DNA interaction and anticancer activity of 2-anthryl substituted benzimidazole derivatives}, journal = {New Journal of Chemistry}, volume = {39}, number = {6}, year = {2015}, month = {APR}, pages = {4882-4890}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

2-Anthryl benzimidazole derivatives (5-7) with hydrogen, carboxyl and benzoyl substituents at the 5th position have been synthesized using a silica supported periodic acid catalyst. The DNA cleavage activity of 5-7 was studied in the presence of light using pBR322 plasmid DNA and was shown to vary with substitution at the 5th position of benzimidazole derivatives. DNA binding studies using ethidium bromide displacement assay demonstrated the non-intercalative binding mode of 5-7. The anticancer activity of these target molecules was tested against MCF-7 and HL-60 cell lines, and they exhibited remarkable activity in the micromolar range. Cellular uptake and morphological changes were confirmed by fluorescence and confocal microscopy. A molecular docking study was carried out to explore the DNA binding mechanism of 5-7.

}, issn = {1144-0546}, doi = {10.1039/c4nj02415j}, author = {Sontakke, Vyankat A. and Kate, Anup N. and Ghosh, Sougata and More, Piyush and Gonnade, Rajesh G. and Kumbhar, Navanath M. and Kumbhar, Anupa A. and Chopade, Balu Ananda and Shinde, Vaishali S.} } @article { ISI:000375559600001, title = {Phytogenic silver, gold, and bimetallic nanoparticles as novel antitubercular agents}, journal = {International Journal of Nanomedicine}, volume = {11}, year = {2016}, month = {MAY}, pages = {1889{\textemdash}1897}, publisher = {DOVE MEDICAL PRESS LTD}, address = {PO BOX 300-008, ALBANY, AUCKLAND 0752, NEW ZEALAND}, abstract = {

Purpose: Multi- and extensively drug-resistant tuberculosis (TB) is a global threat to human health. It requires immediate action to seek new antitubercular compounds and devise alternate strategies. Nanomaterials, in the present scenario, have opened new avenues in medicine, diagnosis, and therapeutics. In view of this, the current study aims to determine the efficacy of phytogenic metal nanoparticles to inhibit mycobacteria. Methods: Silver (AgNPs), gold (AuNPs), and gold-silver bimetallic (Au-AgNPs) nanoparticles synthesized from medicinal plants, such as Barleria prionitis, Plumbago zeylanica, and Syzygium cumini, were tested against Mycobacterium tuberculosis and M. bovis BCG. In vitro and ex vivo macrophage infection model assays were designed to determine minimum inhibitory concentration (MIC) and half maximal inhibitory concentration of nanoparticles. Microscopic analyses were carried out to demonstrate intracellular uptake of nanoparticles in macrophages. Besides this, biocompatibility, specificity, and selectivity of nanoparticles were also established with respect to human cell lines. Results: Au-AgNPs exhibited highest antitubercular activity, with MIC of \<2.56 mu g/mL, followed by AgNPs. AuNPs did not show such activity at concentrations of up to 100 mu g/mL. In vitro and ex vivo macrophage infection model assays revealed the inhibition of both active and dormant stage mycobacteria on exposure to Au-AgNPs. These nanoparticles were capable of entering macrophage cells and exhibited up to 45\% cytotoxicity at 30 mu g/mL (ten times MIC concentration) after 48 hours. Among these, Au-AgNPs synthesized from S. cumini were found to be more specific toward mycobacteria, with their selectivity index in the range of 94-108. Conclusion: This is the first study to report the antimycobacterial activity of AuNPs, AgNPs, and Au-AgNPs synthesized from medicinal plants. Among these, Au-AgNPs from S. cumini showed profound efficiency, specificity, and selectivity to kill mycobacteria. These should be investigated further to develop novel TB nanoantibiotics.

}, keywords = {Antimycobacterial agent, Cytotoxicity, drug resistance, Mycobacteria, Nanoparticles, tuberculosis}, issn = {1178-2013}, doi = {10.2147/IJN.S102488}, author = {Singh, Richa and Nawale, Laxman and Arkile, Manisha A. and Wadhwani, Sweety and Shedbalkar, Utkarsha and Chopade, Snehal and Sarkar, Dhiman and Chopade, Balu Ananda} }