title: Enhancement of radiosensitivity of melanoma cells by pegylated gold nanoparticles under irradiation of megavoltage electrons.
abstract: Gold nanoparticles (GNP) have significant potential as radiosensitizer agents due to their distinctive properties. Several studies have shown that the surface modification of nanoparticles with methyl polyethylene glycol (mPEG) can increase their biocompatibility. However, the present study investigated the radiosensitization effects of mPEG-coated GNP (mPEG-GNP) in B16F10 murine melanoma cells under irradiation of 6 MeV Electron beam.
  
  
  
  The synthesized GNP were characterized by UV-Visible spectroscopy, dynamic light scattering, transmission electron microscopy, and zeta potential. Enhancement of radiosensitization was evaluated by the clonogenic assay at different radiation doses of megavoltage electron beams.
  
  
  
  It was observed that mPEG-GNP with a hydrodynamic size of approximately 50 nm are almost spherical and cellular uptake occurred at all concentrations. Both proliferation efficiency and survival fraction decreased with increasing mPEG-GNP concentration. Furthermore, significant GNP sensitization occurred with a maximum dose enhancement factor of 1.22 at a concentration of 30 μM.
  
  
  
  Pegylated-GNP are taken up by B16F10 cancer cells and cause radiosensitization in the presence of 6 MeV electrons. The radiosensitization effects of GNP may probably be due to biological processes. Therefore, the underlying biological mechanisms beyond the physical dose enhancement need to be further clarified.
authors.affiliation: a Department of Medical Physics and Biomedical Engineering, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.|b Radiotherapy and Radiobiology Research Centre, Cancer Institute, Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Mousavi
authors.affiliation: a Department of Medical Physics and Biomedical Engineering, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.|b Radiotherapy and Radiobiology Research Centre, Cancer Institute, Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Hassan Ali
authors.initials: HA
authors.lastname: Nedaei
authors.affiliation: c Department of Medical Physics, Faculty of Medical Sciences , Iran University of Medical Sciences , Tehran , Iran.
authors.forename: Samideh
authors.initials: S
authors.lastname: Khoei
authors.affiliation: a Department of Medical Physics and Biomedical Engineering, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Samira
authors.initials: S
authors.lastname: Eynali
authors.affiliation: d Department of Medical Physics and Biomedical Engineering, Faculty of Medicine , Kermanshah University of Medical Sciences , Kermanshah , Iran.
authors.forename: Karim
authors.initials: K
authors.lastname: Khoshgard
authors.affiliation: a Department of Medical Physics and Biomedical Engineering, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Robatjazi
authors.affiliation: e Biomolecular Image Analysis Group, Research Center for Molecular and Cellular Imaging , Tehran University of Medical Sciences , Iran.
authors.forename: Rasoul
authors.initials: R
authors.lastname: Iraji Rad
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects*; D004583:Electrons / Q000627:therapeutic use; D006046:Gold / Q000008:administration & dosage*; D008545:Melanoma / Q000473:pathology / Q000532:radiotherapy*; D053768:Metal Nanoparticles / Q000008:administration & dosage*; D051379:Mice; D053769:Nanocapsules / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D011882:Radiotherapy, High-Energy / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D053769:Nanocapsules; D011838:Radiation-Sensitizing Agents; D011092:Polyethylene Glycols; D006046:Gold
keywords: Gold; melanoma; nanoparticles; polyethylene glycol; radiosensitivity; radiosensitizers