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1.
Microb Pathog ; 124: 63-69, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30121359

RESUMO

The present study is focused on the synthesis of silver nano particles (Ag NPs) using an aqueous extract of the whole plant of Sida cordifolia as a potential bio-reducing agent and assessment of their antibacterial activity. UV-Vis spectroscopy of composed silver colloidal solution displayed surface Plasmon resonance peak at 420 nm. XRD and TEM analysis revealed the morphology as ultra-small, monodispersed spherical nanoparticles with face-centered cubic structure and mean particle size of 3-6 nm. This ultra-small nano size might owe to the slow reaction time and phytochemicals existing in the S. cordifolia extract. The Ag NPs are trailed for antibacterial activity against 5 fish (Aeromonas hydrophila, Pseudomonas fluorescence, Flavobacterium branchiophilum, Edwardsiella tarda and Yersinia rukeri) and 4 human (Escherichia coli, Klebsiella pneumonia, Bacillus subtilis and Staphyloccocus aureus) bacterial pathogens. In all the cases, Ag NPs from Sida cordifolia plant extract manifested noteworthy antibacterial effects on par with positive control i.e.; Gentamicin.


Assuntos
Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Nanopartículas Metálicas , Sida (Planta)/metabolismo , Prata/metabolismo , Prata/farmacologia , Química Verde/métodos , Microscopia Eletrônica de Transmissão , Extratos Vegetais/metabolismo , Análise Espectral , Difração de Raios X
2.
Res Microbiol ; 175(3): 104091, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37331493

RESUMO

Staphylococcus aureus is typically treated with antibiotics, however, due to its widespread and unselective usage, resistant strains of S. aureus have increased to a great extent. Treatment failure and recurring staphylococcal infections are also brought on by biofilm development, which boosts an organism's ability to withstand antibiotics and is thought to be a virulence factor in patients. The present study investigates the antibiofilm activity of naturally available polyphenol Quercetin against drug-resistant S. aureus. Micro dilution plating and tube adhesion methods were performed to evaluate the antibiofilm activity of quercetin against S. aureus. Quercetin treatment resulted in remarkably reduction of biofilm in S. aureus cells. Further we performed a study to investigate binding efficacies of quercetin with genes icaB and icaC from ica locus involved in biofilm formation. 3D structure of icaB, icaC and quercetin were retrieved from Protein data bank and PubChem chemical compound database, respectively. All computational simulation were carried out using AutoDock Vina and AutoDockTools (ADT) v 1.5.4. In silico study demonstrated a strong complex formation, large binding constants (Kb) and low free binding energy (ΔG) between quercetin and icaB (Kb = 1.63 × 10-5, ΔG = -7.2 k cal/mol) and icaC (Kb = 1.98 × 10-6, ΔG = -8.7 kcal/mol). This in silico analysis indicates that quercetin is capable of targeting icaB and icaC proteins which are essential for biofilm formation in S. aureus. Our study highlighted the antibiofilm activity of quercetin against drug resistant pathogen S.aureus.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Staphylococcus aureus/genética , Staphylococcus aureus Resistente à Meticilina/genética , Quercetina/farmacologia , Quercetina/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Biofilmes , Simulação por Computador , Testes de Sensibilidade Microbiana
3.
Bionanoscience ; 12(1): 274-291, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35096502

RESUMO

Liposomes are well-recognized and essential nano-sized drug delivery systems. Liposomes are phospholipid vesicles comprised of cell membrane components and have been employed as artificial cell models to mimic structure and functions of cells and are of immense use in various biological analyses. Liposomes acquire great advantages and provide wide range of applications as useful drug carriers in pre-clinical and clinical trials. This review summarizes exclusively on scalable techniques for liposome preparation and focuses on the strengths and limitations with respect to industrial applicability. Also, this review discusses the updated recent advancements in biomedical applications with a mention of key highlights of commercially available formulations, clinical trials and patents in recent past. Furthermore, this review also provides brief information of the classification, composition and characterization of liposomes.

4.
Adv Sci (Weinh) ; 8(7): 2003697, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33854895

RESUMO

The direct synthesis of inherently defect-free, large-area graphene on flexible substrates is a key technology for soft electronic devices. In the present work, in situ plasma-assisted thermal chemical vapor deposition is implemented in order to synthesize 4 in. diameter high-quality graphene directly on 10 nm thick Ti-buffered substrates at 100 °C. The in situ synthesized monolayer graphene displays outstanding stretching properties coupled with low sheet resistance. Further improved mechanical and electronic performances are achieved by the in situ multi-stacking of graphene. The four-layered graphene multi-stack is shown to display an ultralow resistance of ≈6 Ω sq-1, which is consistently maintained during the harsh repeat stretching tests and is assisted by self-p-doping under ambient conditions. Graphene-field effect transistors fabricated on polydimethylsiloxane substrates reveal an unprecedented hole mobility of ≈21 000 cm2 V-1 s-1 at a gate voltage of -4 V, irrespective of the channel length, which is consistently maintained during the repeat stretching test of 5000 cycles at 140% parallel strain.

5.
Mater Sci Eng C Mater Biol Appl ; 103: 109756, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31349415

RESUMO

Zinc Oxide (ZnO) is currently used in nano-cosmeceuticals and nano-pharmaceuticals topically due to their multifunctional efficiency irrespective of the synthetic method. Bio-reducers are cosmopolitically famed to attain stable, reliable, and toxic free synthesis. Thus, the objective of the current study is to prepare ZnO NPs in a greener approach using Annona squamosa (AS) leaf extract and to evaluate their antibiotic potentiation capacity and anticancer activity. The novel synthetic process of ZnO NPs was performed without using any chemicals (reducing or stabilizing agents) or high temperature processing under continuous stirring and refluxion in the presence of oxygen environment. AS have renowned phytochemicals with medicinal properties. Therefore, the mounting of secondary metabolites onto ZnO NPs during synthesis as reducing, stabilizing, capping agents may impart additional biomedical efficacy. The ZnO NPs were prepared with the assessment of stabilization (characteristic peak at 375 nm) from absorbance spectra. Further, SEM, TEM, XRD, FTIR, and Raman analysis of AS-ZnO NPs were performed to elucidate the size, shape, nature, chemical structure and composition. The characterization techniques revealed particles of 20-50 nm size, hexagonal shaped crystalline structure with diverse phytochemicals and functional groups. In addition, AS-ZnO NPs were investigated for antibacterial activity along with antibiotic potentiating capability through combinational assay. Furthermore, the anticancer potential of AS-ZnO NPs was evaluated against HeLa cell line along with assessment of biocompatibility on HEK-293 cell line using MTT assay. Based on the findings, our study exploits green-synthesized ZnO NPs as an effective strategy for potentiation of antibiotic activity and anticancer activity in a biocompatible perspective.


Assuntos
Annona/química , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Nanopartículas Metálicas/química , Óxido de Zinco/farmacologia , Antibacterianos/química , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Sinergismo Farmacológico , Química Verde , Células HEK293 , Células HeLa , Humanos , Nanopartículas Metálicas/uso terapêutico , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Folhas de Planta/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios X , Óxido de Zinco/química
6.
Heliyon ; 5(11): e02765, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31799458

RESUMO

The aim of the work is to synthesize iron oxide (α-Fe2O3) nanoparticles using Sida cordifolia plant extract along with evaluation of its antibacterial activity. The presence of phytochemicals in Sida cordifolia methanolic plant extract was investigated by HPTLC and LC-MS/TOF. The probable mechanism for formation of α-Fe2O3 nanoparticles in mediation with plant extract was demonstrated. The green synthesized iron oxide nanoparticles (α-Fe2O3 NPs) were characterized by using X-ray diffraction, scanning, and transmission electronic microscopy, TG-DTA, FTIR, and UV spectroscopy. The crystallite size of prepared α-Fe2O3 nanoparticles estimated via Debye-Scherrer formula and Williamson-Hall plot was around 20 nm which is in accordance with particle size in TEM images. The S. cordifolia mediated iron-oxide nanoparticles (α-Fe2O3 NPs) hold potent antibacterial activity against various gram positive and gram negative bacteria.

7.
Mater Sci Eng C Mater Biol Appl ; 62: 553-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26952458

RESUMO

Since the discovery and subsequent widespread use of antibiotics, a variety of bacterial species of human and animal origin have developed numerous mechanisms that render bacteria resistant to some, and in certain cases to nearly all antibiotics, thereby limiting the treatment options and compromising effective therapy. In the present study, the green synthesis of nanoparticles is carried out by the reduction of silver acetate in the presence of crude methanolic root extracts of Diospyros paniculata, a member of family Ebenaceae. The UV-Vis absorption spectrum of the biologically reduced reaction mixture showed the surface plasmon peak at 428 nm, a characteristic peak of silver nanoparticles. X-ray diffraction (XRD) analysis confirmed the face-centered cubic crystalline structure of metallic silver. The average diameter of Ag NPs is about 17 nm from Transmission Electron Microscopy (TEM) which is in good agreement with the average crystallite size (19 nm) calculated from XRD analysis. Further the study has been extended to the antimicrobial activity against test pathogenic Gram (+), Gram (-) bacterial and fungal strains. The biologically synthesized silver nanoparticles showed promising activity against all the tested pathogenic strains and the activity has been enhanced with the increased dose levels.


Assuntos
Anti-Infecciosos/química , Diospyros/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata/química , Anti-Infecciosos/farmacologia , Diospyros/metabolismo , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Nanopartículas Metálicas/toxicidade , Metanol/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Espectrofotometria Ultravioleta , Difração de Raios X
8.
Gene ; 142(2): 265-70, 1994 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-8194762

RESUMO

The cloning and sequence analysis of a gene that encodes a lipid transfer protein (LTP) from rice is reported. A genomic DNA library from Oryza sativa was screened using a cDNA encoding a maize LTP. One genomic clone containing the gene (Ltp) was partially sequenced and analyzed. The open reading frame is interrupted by an 89-bp intron. From the results of Southern hybridizations, Ltp appears to be a member of a small multigenic family. Transcripts of the corresponding gene were detected in several tissues including coleoptile, leaf, endosperm, scutellum and root. The transcription start point was determined by primer extension. The deduced amino-acid sequence of the Ltp product is shown to be homologous to LTPs from other crops.


Assuntos
Proteínas de Transporte/genética , Genes de Plantas/genética , Oryza/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Antígenos de Plantas , Composição de Bases , Sequência de Bases , Clonagem Molecular , Dados de Sequência Molecular , Família Multigênica/genética , Oryza/química , Regiões Promotoras Genéticas/genética , RNA Mensageiro/análise , Análise de Sequência de DNA , Transcrição Gênica
9.
Theor Appl Genet ; 89(1): 80-8, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24177774

RESUMO

Conditions have been identified that allow reproducible amplification of RAPD markers in sorghum. High resolution of RAPD markers was accomplished by radiolabeling PCR-amplified DNAs followed by separation on denaturing 5% polyacrylamide gels. Reaction parameters including MgCl2 concentration and temperature significantly influenced yield and the type of amplification products synthesized. Unexplained amplified DNAs increased when more than 35 cycles of PCR amplification were used. Under standard conditions, approximately 80% of the primers tested amplified DNA, and most revealed 1-5 polymorphisms between BTx 623 and IS 3620C. Primers were used to amplify RAPDs in 32 genotypes of sorghum. In addition, 8 primers detected RAPDs in a population previously used to create an RFLP map for sorghum. These RAPDs were mapped successfully using a population of 50 F2 plants.

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