Graphene Oxide (GO): A Promising Nanomaterial against Infectious Diseases Caused by Multidrug-Resistant Bacteria

Abstract

Infectious diseases are major threat due to it being the main cause of enormous morbidity and mortality in the world. Multidrug-resistant (MDR) bacteria put an additional burden of infection leading to inferior treatment by the antibiotics of the latest generations. The emergence and spread of MDR bacteria (so-called "superbugs"), due to mutations in the bacteria and overuse of antibiotics, should be considered a serious concern. Recently, the rapid advancement of nanoscience and nanotechnology has produced several antimicrobial nanoparticles. It has been suggested that nanoparticles rely on very different mechanisms of antibacterial activity when compared to antibiotics. Graphene-based nanomaterials are fast emerging as "two-dimensional wonder materials" due to their unique structure and excellent mechanical, optical and electrical properties and have been exploited in electronics and other fields. Emerging trends show that their exceptional properties can be exploited for biomedical applications, especially in drug delivery and tissue engineering. Moreover, graphene derivatives were found to have in vitro antibacterial properties. In the recent years, there have been many studies demonstrating the antibacterial effects of GO on various types of bacteria. In this review article, we will be focusing on the aforementioned studies, focusing on the mechanisms, difference between the studies, limitations and future directions.

Keywords: antibacterial; graphene oxide; infectious disease; mechanism of action; multidrug-resistant.

Figure 1

Bacteria acquire resistance toward antibacterial agents (antibiotics) through various mechanisms. (1) Efflux pump activity, in which the intracellular antibiotics are removed from the bacteria cells, which prevents the accumulation of antibiotics at its therapeutic concentrations, intracellularly. (2) Inactivation of enzymes, such as beta-lactamase, and (3) modification of antibiotics targets, such as alterations of the penicillin-binding protein (ABP) and DNA gyrase.

Figure 2

Illustration of the antibacterial mechanisms of GO, which consist of (1) penetration and disruption of the bacterial cell membrane, (2) leakage of the intracellular content following penetration and disruption of the cell membrane, (3) oxidative stress by the generation of reactive oxygen species (ROS0 and depletion of the antioxidant in the bacteria) and (4) bacteria entrapping (wrapping effect) by GO.