Cytotoxic studies of PEG functionalized ZnO Nanoparticles on MCF-7 cancer cells

We have synthesized the polyethylene glycol (PEG) functionalized zinc oxide nanoparticles (ZnONPs) and studied their cytotoxic effect on MCF-7 breast cancer cells using the MTT cell viability assay. Stable suspensions of ZnONP were produced in ethanol at room-temperature. The nanoparticles were then functionalized by mixing with an aqueous solution of PEG (MW = 8,000) under constant stirring for 24hrs. The solution was then centrifuged and lyophilized for characterization. X-ray diffraction characterization suggests the formation of wurtzite structure of ZnO. UV-visible and photoluminescence measurements exhibit the characteristic optical properties of ZnO and indicate the formation of ZnO nanoparticles. FTIR studies indicate the functionalization of the ZnO nanoparticle surface with PEG. The cell viability assay suggests the higher cytotoxicity for bare ZnO compared to PEG-ZnO nanoparticles. Further enhancement in the toxicity with UV illumination indicate the possibility to use these particles for photodynamic therapy.