Silver nanoparticles as an alternative strategy against bacterial biofilms.

Abstract

Biofilms are complex bacterial communities that resist the action of antibiotics and the human immune system. Bacteria within biofilms are the cause of numerous, almost impossible to eradicate, persistent infections. Biofilms can form on many medical devices and implants, and so have an enormous impact on medicine. Due to the lack of effective anti-biofilm antibiotics, novel alternative compounds or strategies are urgently required. This review describes some of the latest approaches in the field of biofilm treatment. New anti-biofilm technologies target different stages in the biofilm formation process. Some act to modify the colonized biomaterials to make them resistant to biofilm formation. One potentially important candidate treatment uses silver nanoparticles that show anti-bacterial and anti-biofilm activity. The biological action of nano-silver is complex and seems to involve a number of pathways. However, there have been few reports on the anti-biofilm activity of silver nanoparticles and the precise mechanism underlying their action remains unresolved. Here, we describe some anti-biofilm approaches employing AgNPs and consider the challenges and problems that need to be addressed in order to make silver nanoparticles a part of an effective anti-biofilm strategy.

The silver lining: towards the responsible and limited usage of silver

“…This enhanced activity of stabilized nanoparticles is also attributed to the stabilizing agent which prevents the aggregation of particles into larger forms that can significantly decrease their activity (Markowska et al . ). Synergistic effect of biogenic AgNPs has also been studied with plant products and antibiotics on the biofilms of clinical isolates of Staph.…”

“…Enhanced biofilm inhibition in polymer-stabilized nanoparticles is due to the inhibition of exopolysaccharide synthesis limiting the formation of biofilm ) and the diffusion of CS-AgNPs through the channels present in the biofilms followed by the sustained release of antimicrobial metal nanoparticles . This enhanced activity of stabilized nanoparticles is also attributed to the stabilizing agent which prevents the aggregation of particles into larger forms that can significantly decrease their activity (Markowska et al 2013). Synergistic effect of biogenic AgNPs has also been studied with plant products and antibiotics on the biofilms of clinical isolates of Staph.…”

Microbially synthesized nanoparticles as next generation antimicrobials: scope and applications

“…The colonization and growth of Mycobacterium smegmatis biofilm on membranes was decreased by over 98.7% when coated with Ag-NPs, with an average diameter 12.6 6 5.7 nm at a concentration of 100 μM. The biofilm formation by S. aureus and P. aeruginosa was notably arrested by 65% and 88%, respectively, in presence of starch-stabilized nanoparticles (B20 nm in diameter), even at very low concentrations of 1À2 mM (Markowska et al, 2013).…”

The Potential of Metal Nanoparticles for Inhibition of Bacterial Biofilms

“…However, the number of these reports is still incomparable with the work showing AgNP activity toward planktonic cells. Moreover, the mechanisms of AgNP antibacterial activity remain not fully understood, certainly because of the pleiotropic effect, and further studies are needed to be undertaken to reveal this in detail (for a review see Markowska et al, 2013). The literature concerning the mechanisms of AgNP antibiofilm activity is so far scarce.…”