Nima Hamzian - Department of Medical Physics, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Maryam Hashemi - Nanotechnology Research Center, Institute of Pharmaceutical Technology, Mashhad University of Medical Sciences, Mashhad, Iran.
Mahdi Ghorbani - Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Mohammad Ramezani - Pharmaceutical Research Center, Institute of Pharmaceutical Technology, Mashhad University of Medical Sciences, Mashhad, Iran. Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Mohammad Hossein Bahreyni Toosi - Medical Physics Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

Abstract This study aimed to modify the biological response of cells to ionizing radiation by combination therapy using radio-sensitizer agent and anticancer drug. Super paramagnetic iron oxide nanoparticles (SPIONs) were prepared and used with gemcitabine (Gem). These two agents were encapsulated simultaneously into poly (D, L-lactic-co-glycolic acid) (PLGA) to form multifunctional drug delivery system. The physicochemical characteristics of the nanoparticles (NPs) were studied. The dose enhancement ratio (DER) of various treatment groups was calculated and compared using human breast cancer cell line (MCF-۷). The DER for PLGA-SPION-Gem was the highest at ۱ Gy ۶۰Co (۳.۱۸). Cumulative effect from simultaneous use of two radiosensitizer (Gem and SPIONs) was observed. Thus, we have successfully developed PLGA NPs loaded with gemcitabine and SPION as a radiosensitizer system which potentially could be used in radiotherapy.

Multifunctional drug delivery system, SPION-PLGA, Gemcitabine, Radiotherapy, Radiosensitizer