Abstract
Nanoparticles have recently emerged as a popular research topic. Because of their potential applications in therapeutic applications, biosynthesized silver nanoparticles (Bio-AgNPs) have gained much attention in recent years. Cell-free extracts (CFE) from a marine culture of actinobacteria and silver nitrate were used to reduce Ag+ ions and create Bio-AgNPs. Nocardiopsis dasonvillei KY772427, a new silver-tolerant actinomycete strain, was isolated from marine water and used to synthesize AgNPs. In order to characterize Bio-AgNPs, UV-Vis spectral analysis, Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and dynamic light scattering spectroscopy (DLS) were all utilized. Using UV–Vis spectroscopy, a peak in the surface plasmon resonance (SPR) spectrum at 430 nm revealed the presence of Bio-AgNPs. The TEM revealed spherical AgNPs with a diameter of 29.28 nm. DLS determined that Bio-AgNPs have a diameter of 56.1 nm and a negative surface charge (−1.46 mV). The minimum inhibitory concentration (MIC) of Bio-AgNPs was determined against microbial strains. Using resazurin-based microtiter dilution, the synergistic effect of Bio-AgNPs with antimicrobials was investigated. Pseudomonas aeruginosa had the lowest MIC of Bio-AgNPs (4 μg/ml). Surprisingly, the combination of antimicrobials and Bio-AgNPs had a significant synergistic effect on the tested strains. The insecticidal activity of Bio-AgNPs (200 μg/ml) against Macrosiphum rosae was found to be maximal after 36 h. Additionally, Bio-AgNPs demonstrated significant scavenging activity against 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH–) radicals, with IC50 values of 4.08 and 8.9 g/ml, respectively. In vitro studies using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay revealed a concentration-dependent decrease in cell viability when CaCo2 cells were exposed to Bio-AgNPs. With the decrease in cell viability, lactate dehydrogenase leakage (LDH) increased. The findings of this study open up a new avenue for the use of marine Nocardiopsis dasonvillei to produce Bio-AgNPs, which have significant antimicrobial, antioxidant, insecticidal, and anticancer potential.
Highlights
Nanoparticles are at the forefront of nanotechnology developments in biomedical research (Makvandi et al, 2020)
This study aims at exploring therapeutic properties of BioAgNPs using cell-free extract (CFE) of N. dassonvillei actinobacterium
Actinobacteria, one of the many microbial groups found in the marine environment, occupy a significant niche as a potential source of novel metabolites and bioactive substances (Ganesan et al, 2017)
Summary
Nanoparticles (materials with a dimension of less than 100 nm) are at the forefront of nanotechnology developments in biomedical research (Makvandi et al, 2020). Recent advancements in nanotechnology have resulted in the widespread use of silver nanoparticles (AgNPs) as antimicrobial, anti-inflammatory, and anticancerous agents (Khalil et al, 2021), since AgNPs have unique optical, magnetic, catalytic, and electronic properties (Sánchez-López et al, 2020). AgNPs agglomerated in the nucleus, mitochondria, and lysosomes, cause significant oxidative damage in these organelles and lead to apoptosis or necrosis (Nikzamir et al, 2021). Another mechanism for AgNPs cytotoxicity is the production of reactive oxygen species (ROS) as a result of disruption of the mitochondrial electron transferring chain, which causes DNA damage (Dos Santos et al, 2014). The potential of AgNPs for therapeutic and biotechnological applications has gained much attention in recent years
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