Investigating the role of phytochemicals in silver nanoparticle as an antibacterial agent using computational and experimental analysis

2021 ◽  
Vol 16 (12) ◽  
pp. 100-108
Author(s):  
Akanksha Dubey ◽  
Jayanthi Sivaraman
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Binding Proteins ◽  
Chemical Constituents ◽  
Experimental Studies ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
Penicillin Binding Proteins ◽  
Synthesis Of Nanoparticles

Designing a powerful approach for the synthesis of metal nanoparticles is a critical footstep in the field of nanotechnology. Algae-mediated synthesis of nanoparticles is a substitute to overthrow the restrictions of traditional methods. Penicillin-binding proteins are proteins binding to β-lactams and are convoluted in cell wall biosynthesis. The present study aimed to investigate the potential role of phytochemicals in inhibiting these penicillin binding proteins against bacterial agents using computational and experimental studies. Biosynthesis of silver nanoparticles was done using aqueous extract of Dictyota bartayresiana and was evaluated for antibacterial activity. Characterization was done via UV-visible spectroscopy, Scanning electron microscopy, Transmission electron microscopy and Xray diffraction studies. It was found that synthesized nanoparticle was spherical in shape and possessed antibacterial property against Staphylococcus aureus and Escherichia coli. Phytochemical screening was performed to identify the chemical constituents present in silver nanoparticles followed by molecular docking studies against penicillin binding proteins found in bacterial strains. In silico designing of silver nanoparticles was done using material science suite followed by probe target interactions. The results displayed a highly stable binding amongst designed nanoparticle and phytochemicals and indicated that the silver nanoparticles possessed antibacterial properties due to phytochemicals present in the extract.

scholarly journals Studies on Biosynthesis of Silver Nanoparticles Using Rhizopus sp. and its Antibacterial Efficacy on E. coli MDR Strains

2014 ◽  
Vol 23 ◽  
pp. 27-35
Author(s):  
Jyothi Hiremath ◽  
Vandana Rathod ◽  
Shivaraj Ninganagouda ◽  
Dattu Singh ◽  
K. Prema
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Human Life ◽  
Antibacterial Properties ◽  
Pharmaceutical Products ◽  
Diffusion Method ◽  
Plasmon Resonance Peak ◽  
Synthesis Of Nanoparticles ◽  
E Coli ◽  
Vis Spectroscopy

Nanotechnology is a field that is burgeoning day by day, making an impact in all spheres of human life. Biological methods of synthesis have paved way for the “greener synthesis” of nanoparticles and these have proven to be better methods due to slower kinetics, they offer better manipulation and control over crystal growth and their stabilization. In this context we have investigated extracellular biosynthesis of silver nanoparticles (AgNPs) using cell-free extract of Rhizopus spp.. Formation of AgNPs was indicated by the change in the colour of the cellfree extract from yellow to dark brown under static condition after 48 hrs of incubation. Characterization of AgNPs was carried out by UV-Vis Spectroscopy which gave sharp plasmon resonance peak at 429 nm corresponding to spherical shaped nanoparticles. Transmission electron microscopy (TEM) micrograph showed formation of well-dispersed AgNPs in the range of 25-50 nm. Scanning electron microscopy (SEM) showed the particles to be uniformly dispersed without agglomeration with smooth morphology. EDS showed the presence of elemental silver at 3kev. X-ray diffraction (XRD)-spectrum of the AgNPs exhibited 2θ¸ values corresponding to nanocrystal. These biosynthesized AgNPs were used to study their antimicrobial activity against Multi-drug resistant (MDR) E. coli strains, by Agar diffusion method. Zone of inhibition was measured. Synthesis of nanosized particles with antibacterial properties, which are called "nanoantibiotics", is of great interest in the development of new pharmaceutical products.

scholarly journals Characterization and Antibacterial Response of Silver Nanoparticles Biosynthesized Using an Ethanolic Extract of Coccinia indica Leaves

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 97
Author(s):  
Suresh V. Chinni ◽  
Subash C. B. Gopinath ◽  
Periasamy Anbu ◽  
Neeraj Kumar Fuloria ◽  
Shivkanya Fuloria ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Ethanolic Extract ◽  
Spherical Shape ◽  
Bacterial Strains ◽  
X Ray ◽  
Coccinia Indica ◽  
Antibacterial Potential

The present study was planned to characterize and analyze the antimicrobial activity of silver nanoparticles (AgNP) biosynthesized using a Coccinia indica leaf (CIL) ethanolic extract. The present study included the preparation of CIL ethanolic extract using the maceration process, which was further used for AgNP biosynthesis by silver nitrate reduction. Biosynthetic AgNPs were characterized using UV–Visible spectrometry, zeta potential analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) spectrometry. The biogenic AgNP and CIL extracts were further investigated against different bacterial strains for their antimicrobial activity. The surface plasmon resonance (SPR) signal at 425 nm confirmed AgNP formation. The SEM and TEM data revealed the spherical shape of biogenic AgNPs and size in the range of 8 to 48 nm. The EDX results verified the presence of Ag. The AgNPs displayed a zeta potential of −55.46 mV, suggesting mild AgNP stability. Compared to Gram-positive bacteria, the biogenic AgNPs demonstrated high antibacterial potential against Gram-negative bacteria. Based on the results, the current study concluded that AgNPs based on CIL extract have strong antibacterial potential, and it established that AgNP biosynthesis using CIL ethanol extract is an effective process.

scholarly journals Role of Penicillin-Binding Proteins in the Initiation of the AmpC β-Lactamase Expression inEnterobacter cloacae

2000 ◽  
Vol 44 (1) ◽  
pp. 169-172 ◽  
Author(s):  
Dieter Pfeifle ◽  
Eva Janas ◽  
Bernd Wiedemann
Keyword(s):  
Escherichia Coli ◽  
Binding Proteins ◽  
Penicillin Binding Proteins

ABSTRACT Penicillin-binding proteins (PBPs) are involved in the regulation of β-lactamase expression by determining the level of anhydromuramylpeptides in the periplasmatic space. It was hypothesized that one or more PBPs act as a sensor in the β-lactamase induction pathway. We have performed induction studies with Escherichia coli mutants lacking one to four PBPs withdd-carboxypeptidase activity. Therefore, we conclude that a strong β-lactamase inducer must inhibit alldd-carboxypeptidases as well as the essential PBPs 1a, 1b, and/or 2.

Synthesis, characterization and application of green seaweed mediated silver nanoparticles (AgNPs) as antibacterial agents for water disinfection

2018 ◽  
Vol 78 (1) ◽  
pp. 235-246 ◽  
Author(s):  
D. Dixit ◽  
D. Gangadharan ◽  
K. M. Popat ◽  
C. R. K. Reddy ◽  
M. Trivedi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Antibacterial Agents ◽  
Bacterial Count ◽  
Water Disinfection ◽  
Bacterial Strains ◽  
Vis Spectroscopy ◽  
Green Seaweed

Abstract A simple and eco-friendly method for the synthesis of hybrid bead silver nanoparticles (AgNPs) employing the aqueous extract derived from natural and renewable source namely tropical benthic green seaweed Ulva flexuosa was developed. This route involves the reduction of Ag+ ions anchored onto macro porous methacrylic acid copolymer beads to AgNPs for employing them as antibacterial agents for in vitro water disinfection. The seaweed extract itself acts as a reducing and stabilizing agent and requires no additional surfactant or capping agent for forming the AgNPs. The nanoparticles were analyzed using high-resolution transmission electron microscopy, UV–Vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis and inductively coupled plasma optical emission spectroscopy. The study elucidates that such biologically synthesized AgNPs exhibit potential antibacterial activity against two Gram positive (Bacillus subtilis, Staphylococcus aureus) and two Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacterial strains tested. The bacterial count in treated water was reduced to zero for all the strains. Atomic force microscopy was performed to confirm the pre- and post-state of the bacteria with reference to their treatment with AgNPs. Attributes like facile environment-friendly procedure, stability and high antibacterial potency propel the consideration of these AgNPs as promising antibacterial entities.

scholarly journals Green Synthesis and Antibacterial Activity of HAp@Ag Nanocomposite Using Centella asiatica (L.) Urban Extract and Eggshell

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xuan Nui Pham ◽  
Hoa Thi Nguyen ◽  
Ngan Thi Pham
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Green Synthesis ◽  
Antibacterial Properties ◽  
Centella Asiatica ◽  
Diffusion Method ◽  
Ag Nps ◽  
X Ray ◽  
Synthesis Of Nanoparticles ◽  
Green Approach

In recent years, the green synthesis of nanoparticles via biological processes has attracted considerable attention. Herein, we introduce a facile and green approach for the synthesis of poriferous silver nanoparticles (Ag-NPs) decorated hydroxylapatite (HAp@Ag) nanoparticles with excellent antibacterial properties. All the nanocomposites were fully characterized in the solid state via various techniques such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometer (EDX), in which the synthesized Ag-NPs (24 nm in diameter) and their homogeneous incorporation on HAp have been studied by ultraviolet-visible (UV-vis) technique, transmission electron microscopy (TEM), and dynamic light scattering (DLS) analysis. The obtained results indicate that the structure and morphology of HAp have no significant changes after the incorporation of Ag-NPs on its surface. Moreover, an impressive antibacterial activity of HAp@Ag nanocomposite against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa has been recorded by using the agar well diffusion method. As a result, the HAp@Ag nanocomposite promises to be a great biomedical material with high antibacterial properties.

Human endolymphatic sac: possible mechanisms of pressure regulation

1987 ◽  
Vol 101 (8) ◽  
pp. 768-779 ◽  
Author(s):  
Phillip Ashley Wackym ◽  
Ulla Friberg ◽  
Dan Bagger-Sjöbäck ◽  
Fred H. Linthicum ◽  
Imrich Friedmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Experimental Studies ◽  
Secretory Activity ◽  
Regulatory Mechanisms ◽  
Endolymphatic Sac ◽  
Pressure Regulation ◽  
Transmission Electron ◽  
Normal Human ◽  
Mechanical Factors

AbstractThe ultrastructure of the normal human endolymphatic sac (ES) has been observed by transmission electron microscopy (TEM). The role of the epithelium, the various regions of the subepithelial space and the general anatomy of the ES in pressure regulation were morphologically studied to generate testable hypotheses of human ES function. Light microscopic (LM) and TEM evidence of pressure regulatory mechanisms by endolymph resorption, mechanical factors, and secretory activity are presented. These mechanisms may be useful in designing experimental studies of the ES, and in interpretation of retrospective LM and TEM studies of patients with Meniere's disease.

Sign in / Sign up

Export Citation Format

Share Document