Journal of Bacteriology & Parasitology

Abstract

In Vitro Study for Comparing the Cytotoxicity of Silver and Gold Nanospheres on Raw 264.7 Murine Macrophage Cell Line

Hala Ragab Khalil Ali, Moawad MS and Selim SA

Silver nanospheres (AgNSs) and gold nanospheres (AuNSs) made a huge commercial and scientific interests due to their antimicrobials potency, use in nanomedicine and drug delivery systems. Macrophages are the primary site for clearing waste substances from tissues and the intracellular infections produced by pathogens like Mycobacterium tuberculosis. Therefore, studying the cytotoxic effects of nanomaterials on such promising model will open new era towards safe use of nanobased treatments of intracellular pathogens. In This study, the effect of three different concentrations (10, 20, 40 μg/ml) of AuNSs and AgNSs with an average diameter of 20 nm was studied on RAW264.7 murine macrophage viability for 3 hours using XTT assay. AuNSs were found nontoxic to macrophages at all tested concentration. However AgNSs showed acute decline in viability of RAW264.7 cells even at the lowest concentration (10 μg/ml). In another experiment, the effect of AuNSs and AgNSs was examined on short and long term manners by treating macrophages with single dose of 20 μg/ml for different time points (0, 10, 20, 30, 60 minutes, 24, and 48 hours). Results revealed that AgNSs induced acute cytotoxicity to macrophages till 48 hours, while gold nanospheres were safe to RAW264.7 cells at all-time points compared to untreated control. Thus the AuNSs might represent a safe drug delivery platform for combating the intracellular pathogens like M. tuberculosis without hurting their host cells.