Multi-functional nano silver: A novel disruptive and theranostic agent for pathogenic organisms in real-time

Abstract

The present study was aimed at evaluating the fluorescence property, sporicidal potency against Bacillus and Clostridium endospores, and surface disinfecting ability of biogenic nano silver. The nano silver was synthesized using an actinobacterial cell-filtrate. The fluorescence property as well as imaging facilitator potency of this nano silver was verified adopting spectrofluorometer along with fluorescent and confocal laser scanning microscope wherein strong emission and bright green fluorescence, respectively, on the entire spore surface was observed. Subsequently, the endospores of B. subtilis, B. cereus, B. amyloliquefaciens, C. perfringens and C. difficile were treated with physical sporicides, chemical sporicides and nano silver, in which the nano silver brought about pronounced inhibition even at a very low concentration. Finally, the environmental surface-sanitizing potency of nano silver was investigated adopting cage co-contamination assay, wherein vital organs of mice exposed to the nano silver-treated cage did not show any signs of pathological lesions, thus signifying the ability of nano silver to completely disinfect the spore or reduce the count required for infection. Taken these observations together, we have shown the multi-functional biological properties of the nano silver, synthesized using an actinobacterial cell-filtrate, which could be of application in advanced diagnostics, biomedical engineering and therapeutics in the near future.

Fungal-Derived Nanoparticles as Novel Antimicrobial and Anticancer Agents

“…As described earlier, larger surface area of silver nanoparticles are believed to be key player in interaction with bacterial cell wall and would have resulted in more antibacterial activity. Although mechanism of action of silver NPs on bacterial cell is debatable; however, assumed mechanism include (i) adherence of AgNPs with bacterial cell wall causing membrane lysis, ultimately releasing cellular contents leading to destruction of cell structure and death [89][90][91], (ii) interaction of Ag ions with free thiol groups (−SH) and disulfide bridges (-S-S-) of cellular enzymes and membrane of bacteria to downregulate or inactivate the cellular protein synthesis by interfering the translation [72,91,92], (iii) blocking DNA replication [93], and (iv) inhibition of signal transduction by dephosphorylation of peptide substrates on tyrosine residues (Figure 2) [91]. Furthermore, inhibitory effect of AgNPs varied for different bacterium, e.g., Gram-positive bacteria were more susceptible to silver nanoparticles as compared to Gram-negative one [84].…”

Effects of Local Application of Nano-silver on Osteomyelitis and Soft Tissue Infections: An Experimental Study in Rats

“…Gopinath et al . found that biogenic AgNPs are effective against endospores of Bacillus and Clostridium species 31 . Wang et al .…”

Applications of Noble Metal-Based Nanoparticles in Medicine

“…For example, Liu and co-authors have used gold nanoparticles for imaging (SERS, CT, and TPL imaging) and photothermal therapy in mouse models of sarcomas and shown that gold nanostars are more effective than gold nanoshells [88]. There are also reports on the theranostic application of Ag NPs or Pt NPs [89,90].…”