Selective antibacterial and apoptosis-inducing effects of hybrid gold nanoparticles - A green approach

The development of novel approaches in the biosynthesis of gold nanoparticles has significantly gained tremendous attention in the medical field. In the present study, an aqueous seaweed extract of the marine brown algae S. ilicifolium has been used for the synthesis of hybrid gold nanoparticles. The gold nanoparticles were found to be near-spherical in shape and size of 20-25 nm. Altogether, phytoconstituents such as polyols, proteins, and aromatic compounds play an important role in capping and stabilizing the hybrid gold nanoparticles. The hybrid gold nanoparticles were found to be crystalline as evidence by X-ray diffraction studies. We also demonstrated that synthesized hybrid gold nanoparticles exert antibacterial activity at 48 +/- 1.36 mu g mL(-1) and cause selective cell death of Staphylococcus aureus by generating an enhanced level of intracellular ROS. Further, upon treatment with hybrid gold nanoparticles (24 +/- 1.94 mu gmL(-1)), the breast cancer cell lines showed more apoptotic features such as loss of membrane integrity and chromatin condensation when compared to the control groups. The biocompatibility assessment of hybrid gold nanoparticles in Artemia sauna revealed that it does not elicit any lethal effect even at 250 mu gmL(-1). Taken together, these findings suggest that a hybrid nanoparticle from S. illicifolium is eco-friendly, has selective antibacterial activity, and effectively kills breast cancer cells by inducing apoptosis.