Silver nanoparticles as potential antibacterial agents

Abstract

Multi-drug resistance is a growing problem in the treatment of infectious diseases and the widespread use of broad-spectrum antibiotics has produced antibiotic resistance for many human bacterial pathogens. Advances in nanotechnology have opened new horizons in nanomedicine, allowing the synthesis of nanoparticles that can be assembled into complex architectures. Novel studies and technologies are devoted to understanding the mechanisms of disease for the design of new drugs, but unfortunately infectious diseases continue to be a major health burden worldwide. Since ancient times, silver was known for its anti-bacterial effects and for centuries it has been used for prevention and control of disparate infections. Currently nanotechnology and nanomaterials are fully integrated in common applications and objects that we use every day. In addition, the silver nanoparticles are attracting much interest because of their potent antibacterial activity. Many studies have also shown an important activity of silver nanoparticles against bacterial biofilms. This review aims to summarize the emerging efforts to address current challenges and solutions in the treatment of infectious diseases, particularly the use of nanosilver antimicrobials.

Keywords: AgNPs; antibacterial; biofilm; resistence.

Figure 1

Mechanisms of AgNPs’ toxic action.

Figure 2

Schematic representation of various cellular responses to AgNP-induced toxicity mechanisms. In particular AgNPs induce mitochondrial and DNA damage by ROS.

Figure 3

Planktonic cells adhere to the surface and proliferate. During biofilm maturation, the extracellular matrix and quorum sensing molecules are produced. Mature biofilms are generally characterized by an increased abundance of matrix materials, slow-growing bacterial cells in the centre, and fragmentation which leads to cell detachment and spread of infection.