title: Role of iron oxide core of polymeric nanoparticles in the thermosensitivity of colon cancer cell line HT-29.
abstract: OBJECTIVE
  In this study the effect of PLGA polymeric nanoparticles as a 5-fluorouracil (5-FU) carrier with and without iron oxide core and hyperthermia were investigated on the level of DNA damage in a spheroid culture model of HT-29 colon cancer cell lines by alkaline comet assay.
  
  
  METHODS
  First, HT-29 colon cancer cells were cultured in vitro as spheroids with a mean diameter of 100 µm. The spheroids were then treated with different concentrations of 5-FU or nanoparticles as 5-FU carriers with and without an iron oxide core for one volume-doubling time of the spheroids (71 h) and hyperthermia at 43 °C for 1 h. Finally, the effect of treatment on viability and level of DNA damage was examined using trypan blue dye exclusion assay and alkaline comet assay, respectively.
  
  
  RESULTS
  Results showed that hyperthermia in combination with 5-FU or nanoparticles as 5-FU carriers significantly induced the most DNA damage as compared with the control group. The extent of DNA damage following treatment with 5-FU-loaded nanoparticles combined with hyperthermia was significantly more than for 5-FU combined with hyperthermia. In comparison to the effect of 5-FU-loaded nanoparticles with the iron oxide core and 5-FU-loaded nanoparticle without the iron oxide core, the nanoparticles with the iron oxide core combined with hyperthermia induced more DNA damage than the nanoparticles without the iron oxide core.
  
  
  CONCLUSIONS
  According to this study, hyperthermia is a harmful agent and nanoparticles are effective delivery vehicles for drugs into colon cancer cells. The iron oxide filled nanoparticles increased the effect of the hyperthermia. All these factors have a significant role in the treatment of colorectal cancer cells.
authors.affiliation: Medical Physics and Biomedical Engineering Department, School of Medicine, Tehran University of Medical Sciences (TUMS) , Tehran .
authors.forename: Elaheh
authors.initials: E
authors.lastname: Esmaelbeygi
authors.forename: Samideh
authors.initials: S
authors.lastname: Khoei
authors.forename: Sepideh
authors.initials: S
authors.lastname: Khoee
authors.forename: Samira
authors.initials: S
authors.lastname: Eynali
mesh_terms: D003110:Colonic Neoplasms / Q000235:genetics*; D020552:Comet Assay / Q000379:methods*; D004337:Drug Carriers; D005290:Ferric Compounds / Q000737:chemistry*; D005334:Fever / Q000235:genetics*; D005472:Fluorouracil / Q000627:therapeutic use*; D019073:HT29 Cells; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers
chemical_list: D004337:Drug Carriers; D005290:Ferric Compounds; D011108:Polymers; C000499:ferric oxide; D005472:Fluorouracil
keywords: 5-Flurouracil; Colon cancer; PLGA nanoparticle with and without iron oxide core; comet assay; hyperthermia