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Bandyopadhyay, P.

Publications and source records attributed to Bandyopadhyay, P..

2 recordsLinked to original sources
bioRxiv2022

Anti-Biofilm Potential of Nanonized Eugenol against Pseudomonas aeruginosa

This study dealt with nanonization of eugenol, a major phytochemical present in basil leaf, which has pharmacological potential as an anti-bacterial agent. Eugenol nanoparticle (ENP) was synthesized by simple ultrasonic cavitation method through emulsification of hydrophobic eugenol into hydrophilic gelatin. Thus, the nanonization process made the water-insoluble eugenol to water-soluble nano-eugenol, making the nano-form bioavailable. The average size of the ENPs was 20-30 nm. Entrapment efficiency of eugenol within gelatin cap was about 80% of the eugenol, that was used as precursor in the nanonization reaction. In vitro release of eugenol from gelatin cap was slow and sustained over a period of five days. The ENP had higher anti-biofilm potency than eugenol for both formation and eradication of biofilm, formed by clinically relevant pathogen Pseudomonas aeruginosa. Minimal biofilm inhibitory concentration and minimal biofilm eradication concentration of ENPs were 2.0 and 4.0 mM respectively. In addition, the measurement of P. aeruginosa biofilm biomass, biofilm pellicle formation, biofilm thickness, amount of biofilm-forming extra-polymeric substance, cell surface hydrophobicity, cell swarming and twitching efficiencies, cellular morphology and biofilm formation in catheter demonstrated that the anti-biofilm efficacy of nano-eugenol was 30-40% higher than that of bulk eugenol. Thus, ENP can be used as a potential drug against pneumonia, a chronic infection in lung caused by P. aeruginosa, which is difficult to treat with antibiotics, due to natural intrinsic resistance of biofilm-formed cells to most antibiotics. The overall actions of ENP have been presented in the figure 1. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=146 SRC="FIGDIR/small/521144v1_fig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@12445e2org.highwire.dtl.DTLVardef@6813aforg.highwire.dtl.DTLVardef@e4779borg.highwire.dtl.DTLVardef@1688a9a_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1:C_FLOATNO Graphical abstract showing overall anti-biofilm action of ENP that is capable to inhibit each and every step of biofilm formation. ENP also carries the potential to destroy EPS and kill the biofilm residing cells by membrane disruption. Bacterial colonization has been found to be prevented significantly on ENP-coated catheter. C_FIG HighlightsO_LINano-formulation of eugenol, an important phytochemical, by ultrasonic cavitation method, which was simple, time-saving, low-cost and eco-friendly. C_LIO_LINanonization made water-insoluble eugenol into water-soluble form with enhanced therapeutic efficacy. C_LIO_LIThe eugenol nanoparticle (ENP) could inhibit formation of biofilm as well as facilitate eradication of pre-formed biofilm of P. aeruginosa. C_LIO_LIBiofilm formation was found to be prevented significantly on ENP-coated catheter. C_LIO_LINano-eugenol may be used as a potential drug against bacterial diseases, caused by pseudomonal biofilm, which are difficult to treat by antibiotics. C_LIO_LINano-formulated eugenol may also be used as an effective anti-fouling agent for biomedical devices like contact lens, pace-maker, materials for organ transplantation etc. to prevent bacterial colonization. C_LI

microbiology↗
bioRxiv2022

A strategy to optimize the peptide-based inhibitors against different mutants of the spike protein of SARS-CoV-2

SARS-CoV-2 virus has caused high-priority health concerns at a global level. Vaccines have stalled the proliferation of viruses to some extent. Yet, the emergence of newer, potentially more infectious, and dangerous mutants such as delta and omicron are among the major challenges in finding a more permanent solution for this pandemic. The effectiveness of antivirals Molnupiravir and Paxlovid, authorized for emergency use by the FDA, are yet to be assessed at larger populations. Patients with a high risk of disease progression or hospitalization have received treatment with a combination of antibodies (antibody-cocktail). Most of the mutations leading to the new lineage of SARS-CoV-2 are found in the spike protein of this virus that plays a key role in facilitating host entry. The current study has investigated how to modify a promising peptide-based inhibitor of spike protein, LCB3, against common mutations in the target protein so that it retains its efficacy against the spike protein. LCB3 being a prototype for protein-based inhibitors is an ideal testing system to learn about protein-based inhibitors. Two common mutations N501Y and K417N are considered in this work. Using a structure-based approach that considers free energy decomposition of residues, distance, and the interactions between amino acids, we propose the substitutions of amino acid residues of LCB3 inhibitors. Our binding free energy calculations suggest a possible improvement in the binding affinity of existing inhibitor LCB3 to the mutant forms of the S-protein using simple substitutions at specific positions of the inhibitor. This approach, being general, can be used in different inhibitors and other mutations and help in fighting against SARS-CoV-2.

biophysics↗