Potential of silver nanoparticles synthesized from Justicia adhatoda metabolites for inhibiting biofilm on urinary catheters

Abstract

In the present study, we investigated the anti-biofilm effect of urinary catheters fabricated with biogenic nanoparticles synthesized from metabolites of Justicia adhatoda under in vitro conditions against human pathogenic bacteria. Silver nanoparticles were synthesized in the reaction mixture composed of 2 % w/v of 0.1 M of precursor (silver nitrate) and 0.2 g of the metabolites obtained from ethanolic extract of Justicia adhatoda. Characterization of the nanoparticles was done by UV visible spectroscopy, fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X ray diffraction (XRD) to confirm the structural and functional properties. Primary conformation of nanoparticles synthesis by UV visible spectroscopy revealed the notable absorption spectra at 425 nm with a wavelength shift around 450 nm, likely due to surface plasmon resonance excitation. SEM analysis showed spherical, monodisperse, nano scale particles with a size range of 50–60 nm. Crystaline phase of the synthesized nanoparticles was confirmed by x ray diffraction studies which showed the distinct peaks at (2θ) 27.90, 32.20, 46.30, 54.40, and 67.40, corresponding to (111), (200), (220), (222), and (311) planes of nano scale silver. The biocompatibility of these nanoparticles was assessed through zebrafish embryonic toxicity study which showed more than 90 % of embryos were alive and healthy. No marked changes on the blood cells also confirmed best hemocompatibility of the nanoparticles. Synthesized nanoparticles thus obtained were fabricated on the urinary catheter and the fabrication was confirmed by FTIR and SEM analysis. Notable changes in the absorption peaks, uniform coating and embedding of silver nanoparticles studied by FTIR and SEM analysis confirmed the fabrication of silver nanoparticles. The coated catheters demonstrated significant antibacterial activity against pathogenic bacterial strains, including E. coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. Anti-biofilm studies, conducted using a modified microtiter plate crystal violet assay, revealed effective inhibition of both bacterial adhesion and biofilm development. 85 % of biofilm inhibition was recorded against both the tested strains. The coating method presented in this study shows promise for enhancing infection resistance in commonly used medical devices like urinary catheters, thus addressing device-associated infections.