Authors: Nur Shafawati binti Rosli, Azhar Abdul Rahman, Azlan Abdul Aziz and Shaharum Shamsuddin
In treating cancer, radiation therapy and chemotherapy remain the most widely used treatment options. Recent developments in cancer research show that therapy combined with metallic nanoparticles is a new way to treat cancer, in which gold nanoparticles (AuNPs) are injected through intravenous administration and bound to tumor sites has enhanced tumor cell killing. Radiotherapy aims to deliver a high therapeutic dose of ionizing radiation to the tumor without exceeding normal tissue tolerance. The use of AuNPs in megavoltage photon beams radiotherapy will provide a high probability for photon interaction by Compton interaction. These provide advantages in terms of radiation dose enhancement. In Compton interaction, a relatively high energy photon interacts with a loosely bound electron in an atom’s outer shell which is also called as free electron. In this work, breast cancer cell lines (MCF-7) are seeded in the 96-well plate and were treated with 13 nm, 50 nm and 70 nm AuNPs before they were irradiated with 6 MV photon beam from a medical linear accelerator at various radiation doses. To validate the enhanced killing effect, both with and without AuNPs MCF-7 cells is irradiated simultaneously. By comparison, the results show that AuNPs significantly enhance cancer killing and the enhancement radiation effect was dependent on the size of AuNPs.
Keywords: AuNPs; MCF-7 cells; megavoltage; Compton.