Green Synthesis of Iron Nanoparticles for Investigation of Biofilm Inhibition Property

Biofilm-producing antibiotic-resistant bacteria in Indian patients: a comprehensive review

For the past few years, microbial biofilms have been emerging as a significant threat to the modern healthcare system, and their prevalence and antibiotic resistance threat gradually increase daily among the human population. The biofilm has a remarkable impact in the field of infectious diseases, in particular healthcare-associated infections related to indwelling devices such as catheters, implants, artificial heart valves, and prosthetic joints. Bacterial biofilm potentially adheres to any biotic or abiotic surfaces that give specific shelter to the microbial community, making them less susceptible to many antimicrobial agents and even resistant to the immune cells of animal hosts. Around thirty clinical research reports available in PUBMED have been considered to establish the occurrence of biofilm-forming bacteria showing resistance against several regular antibiotics prescribed against infection by clinicians among Indian patients. After the extensive literature review, our observation exhibits a high predominance of biofilm formation among bacteria such as Escherichia sp., Streptococcus sp., Staphylococcus sp., and Pseudomonas sp., those are the most common biofilm-producing antibiotic-resistant bacteria among Indian patients with urinary tract infections and/or catheter-related infections, respiratory tract infections, dental infections, skin infections, and implant-associated infections. This review demonstrates that biofilm-associated bacterial infections constantly elevate in several pathological conditions along with the enhancement of the multi-drug resistance phenomenon.

Biocatalysis as a Green Approach for Synthesis of Iron Nanoparticles—Batch and Microflow Process Comparison

There is a growing need for production of iron particles due to their possible use in numerous systems (e.g., electrical, magnetic, catalytic, biological and others). Although severe reaction conditions and heavy solvents are frequently used in production of nanoparticles, green synthesis has arisen as an eco-friendly method that uses biological catalysts. Various precursors are combined with biological material (such as enzymes, herbal extracts, biomass, bacteria or yeasts) that contain chemicals from the main or secondary metabolism that can function as catalysts for production of nanoparticles. In this work, batch (“one-pot”) biosynthesis of iron nanoparticles is reviewed, as well as the possibilities of using microfluidic systems for continuous biosynthesis of iron nanoparticles, which could overcome the limitations of batch synthesis.

A novel synthesis, analysis and evaluation of Musa coccinea based zero valent iron nanoparticles for antimicrobial and antioxidant

Zerovalent Iron Nanoparticles (MC-ZVI NPs) were synthesized from Musa coocinea peel extract as reducing and stabilizing agent using a novel synthesis technique. The synthesis of MC-ZVI NPs was confirmed using UV-vis spectroscopy showing a sharp absorption peak at 341 nm. Further the chemical and structural characterization of MC-ZVI NPs were performed using Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering technique (DLS). FTIR analysis revealed the presence of phytochemical molecules associated with the MC-ZVI NPs. SEM analysis revealed the synthesized MC-ZVI NPs were in spherical shaped, while DLS analysis confirmed the synthesis of poly dispersed and non-homogenous MC-ZVI NPs. The antimicrobial efficacy of MC-ZVI NPs synthesized using Musa coccinea peel extract was tested against bacterial (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Bacillus subtilis) and fungal (Aspergillus niger) pathogens. But MC-ZVI NPs exhibited maximum of 19 mm zone of inhibition against B. subtilis and A. niger. Further the free radical scavenging activity MC-ZVI NPs was confirmed using DPPH, hydroxyl radical, hydrogen peroxide, FRAP assay showing displayed effective antioxidant activity. Thus, the present idea will give a fast and cost effective approach to synthesize MC-ZVI NPs with antimicrobial property for application in biomedical purposes.

In silico studies on structural inhibition of SARS-CoV-2 main protease Mpro by major secondary metabolites of Andrographis paniculata and Cinchona officinalis

The COVID-19 infection by Novel Corona Virus (SARS-CoV-2) has become one of the largest pandemic diseases, with cumulative confirmed infections of 275,233,892 and 5,364,996 deaths to date according to World Health Organization. Due to the absence of any approved antiviral drug to treat COVID-19, its lethality is getting severe with time. The main protease of SARS-CoV-2, M^pro is considered one of the potential drug targets because of its role in processing proteins translated from viral RNA. In the present study, four of the plant metabolites, 14-deoxy-11,12-didehydroandrographolide, andrograpanin, quinine, cinchonine from two eminent medicinal plants Andrographis paniculata and Cinchona officinalis, have been evaluated against the main protease of SARS-CoV-2 through in-silico molecular docking and molecular dynamics simulation study. From the result interpretations, it is found that andrograpanin has strong binding affinities with the target protein in its active site with potential negative energies. Molecular Dynamic simulation and MMGBSA studies suggest that earlier reported N3 inhibitor and andrograpanin exhibit effective binding interactions involving identical amino acid residues with the same binding pockets of the main protease of SARS-CoV-2. Therefore, the theoretical experiment suggests that andrograpanin, could be considered the promising inhibitor against SARS-CoV-2 M^pro.