Silver nanoparticles: mechanism of antimicrobial action, synthesis, medical applications, and toxicity effects

Abstract

Silver nanoparticles are nanoparticles of silver which are in the range of 1 and 100 nm in size. Silver nanoparticles have unique properties which help in molecular diagnostics, in therapies, as well as in devices that are used in several medical procedures. The major methods used for silver nanoparticle synthesis are the physical and chemical methods. The problem with the chemical and physical methods is that the synthesis is expensive and can also have toxic substances absorbed onto them. To overcome this, the biological method provides a feasible alternative. The major biological systems involved in this are bacteria, fungi, and plant extracts. The major applications of silver nanoparticles in the medical field include diagnostic applications and therapeutic applications. In most of the therapeutic applications, it is the antimicrobial property that is being majorly explored, though the anti-inflammatory property has its fair share of applications. Though silver nanoparticles are rampantly used in many medical procedures and devices as well as in various biological fields, they have their drawbacks due to nanotoxicity. This review provides a comprehensive view on the mechanism of action, production, applications in the medical field, and the health and environmental concerns that are allegedly caused due to these nanoparticles. The focus is on effective and efficient synthesis of silver nanoparticles while exploring their various prospective applications besides trying to understand the current scenario in the debates on the toxicity concerns these nanoparticles pose.

Silver nanoparticles reduce the apoptosis induced by tumor necrosis factor-α

“…Several researchers have investigated the effects of AgNPs on the bacterial wall and how AgNPs inhibit bacterial growth [11, 12, and 13]. However, despite these studies, the exact mechanism underlying the anti-inflammatory effect of AgNPs is not clearly understood.…”

Antibacterial activity of silver nanoparticles: A surface science insight

“…Several articles have also been written to explain mechanistically the mode of action of silver nanoparticles [15][16][17][18][19]. However, most work focused on the empirical observations of effects that lead to the eradication of the target microbes, and very little rationalization on the general antimicrobial pathways was performed.…”

“…Only general trends will thus be described. More information can be found in excellent reviews on the subject [15][16][17][18][19]. Additionally, toxicity issues for humans (systemic and at the cellular level) are topics of primary concern related to Ag NPs, but will not be developed here.…”

Silver nano fabrication using leaf disc of Passiflora foetida Linn

“…The optimization and editing leads to specific size and shape NP potential for human benefits (Sadowski 2010). The plants used for production of nano particles may be pronounced as Phyto-nano factories (Kesharwani et al 2009;Prabhu and Poulose 2012;Bhosale et al 2014). The noble silver (Ag) is the metal of choice for synthesis of nano particles across the field of the biological system, living organisms and medicine.…”