Abstract:
The appearance of multi-drug resistant (MDR) bacteria has become an alarming health issue. The diseases caused by MDR bacteria are increasing at an exponential rate causing the death of millions of people worldwide. About 700,000 people die due to illnesses related to antimicrobial resistance and this figure is expected to rise up to 10 million by 2050. Moreover, the development of new antibiotics is a time consuming and expensive process. Nanoparticles on the other hand provide an alternative to antibiotics which can effectively kill bacteria without inducing resistance in them. A significant number of studies has been performed to investigate the antimicrobial properties and mechanisms of metal and metal oxide nanoparticles including iron, zinc, silver, gold and lead etc. Metallic nanoparticles especially silver nanoparticles are potent antibacterial agents and have been widely used in a number of applications. In the present study silver nanoparticles of both spherical (AgNPs) and cubical shaped (AgNCs) have been synthesized using a simple polyol synthesis approach. The NPs synthesized were subjected to characterization with UV-VIS , SEM, and XRD which confirmed their successful synthesis, their crystalline structure, aspect ratio and shapes. Moreover, the functional groups attached to both types of NPs were found using FTIR analysis. The cytotoxicity of as synthesized AgNPs and AgNCs was evaluated with MTT assay which revealed a dose dependant cytotoxicity and a comparatively high biocompatibility of AgNCs than AgNPs on MCF-7 and MDA-MB-231 cell lines. The DPPH assay showed a higher antioxidant activity of AgNPs as compared to AgNCs. Both the NPs were found to be compatible for use in blood showing negligible haemolytic activities. The antibacterial activity of both the NPs were also evaluated using disk diffusion assay. The AgNPs showed an overall high inhibition zone on all the MDR strains as compared to AgNCs. The AgNCs synthesized in this study can also be used as templates for the synthesis of gold nanocages for cancer diagnosis.
