AUTHOR=Gupta Kshitiz , Chhibber Sanjay 

TITLE=Biofunctionalization of Silver Nanoparticles With Lactonase Leads to Altered Antimicrobial and Cytotoxic Properties

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=6

YEAR=2019

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2019.00063

DOI=10.3389/fmolb.2019.00063

ISSN=2296-889X

ABSTRACT=<p><bold>Background:</bold> N-acylated homoserine lactone lactonase which cleave the Acyl homoserine lactone molecules produced by biofilm-forming pathogens and silver nano-particles (AgNPs), are known for their antibacterial effect against several Gram-positive and Gram-negative bacteria. In this study, AgNPs were coated with N-acylated homoserine lactonase protein (AgNPs-AiiA) isolated from <italic>Bacillus</italic> sp. ZA12.</p><p><bold>Results:</bold> The AgNPs-AiiA complex was characterized by UV-visible spectra, Dynamic light Scattering, Fourier transform infrared spectroscopy (FTIR), and Field Emission Scanning Electron Microscope (Fe-SEM). The synthesized nano-particles were found to be spherical in shape and had an approximate size of 22.4 nm. Treatment with AiiA coated AgNPs showed a significant reduction in exopolysaccharide production, metabolic activity, cell surface hydrophobicity of bacterial cells, and anti-biofilm activity against multidrug-resistant <italic>K. pneumoniae</italic> as compared to treatment with AiiA protein and neat AgNPs. AgNPs-AiiA complex exhibited potent antibiofilm activity at sub-optimal concentration of 14.4 μg/mL without being harmful to the macrophages and to the various tissues including kidney, liver, spleen and lungs of BALB/c mice upon intra-venous administration.</p><p><bold>Conclusion:</bold> It is concluded that at a concentration of 14.4 μg/mL, AgNPs coated with AiiA kill bacteria without harming the host tissue and provides a suitable template to design novel anti-biofilm drug to circumvent the issue of drug resistance.</p>