Najmeh Mozdoori - School of Biology, College of Science, University of Tehran, Tehran, Iran
Shahrokh Safarian - School of Biology, College of Science, University of Tehran, Tehran, Iran

Cancer is one of the leading causes of death, accounting for 8.2 million deaths worldwide in2012. In medicine, nanotechnology has sparked a rapidly growing interest as it promises tosolve a number of issues associated with conventional therapeutic agents, including theirpoor water solubility (at least, for most anticancer drugs), lack of targeting capability,nonspecific distribution, systemic toxicity, and low therapeutic index. Today engineerednanoparticlesdue to their toxicity or as drug delivery agent can be used for cancer therapy.Elemental metal nanoparticles such as cadmium and silver can induce oxidative stress andapoptosis in various cell types. In this study we synthesized and engineered ZnOnanoparticle, then evaluated breast cancer cell toxicity with MTT assay. Zinc oxidenanoparticles are synthesized here by Tay and Cheng methods albeit with several changes.Briefly, 5mM zinc acetate dihydrate was dissolved in 3 ml di-ethylene glycol refluxed andstirred for 70 min at 160ËšC. Then, the product was remained at the cited temperature for 10min to yield ZnO nanoparticles. These nanoparticles then functionalized with L-Cystein andthen Meso-tetra carboxy phenyl (MTCP). MTCP used as ROS inducer and stabilizer for ZnO.These nanosystems then injected to MCF-7 cell culture medium and cell death assessedwith MTT assay. Our result show that functionalized nanoparticle killed cell with lethalconcentration (LC50) =0.15 v/v, while LC50 of Zno was approximately two fold of it.functionalize (or self assemble monolayer) of ZnO cause slow down LC50 of this. BecauseSAMS lead to stabilization of nanoparticle and aggregation of nanoparticle decreased sopenetration of nanoparticle increased that cause enhancement in Local concentration ofnanoparticle in cells and cell death.

Breast Cancer, Lethal Concentration, MTT Assay, ZnO, Engineered Nanoparticle