title: Synthesis and characterization of dextran coated magnetite nanoparticles for diagnostics and therapy.
abstract: BACKGROUND
  Expansion of efficacious theranostic systems is of pivotal significance for medicine and human healthcare. Magnetic nanoparticles (MNPs) are known as drug delivery system and magnetic resonance imaging (MRI) contrast agent. MNPs as drug carriers have attracted significant attention because of the delivery of drugs loaded onto MNPs to solid tumors, maintaining them in the target site by an external electromagnetic field, and subsequently releasing drugs in a controlled manner. On the other hand, it is believed that MNPs possess high potential as MRI contrast agents. The aim of this work was to payload curcumin into dextran coated MNPs and investigate their potential as theranostic systems for controlled drug delivery and MRI imaging.
  
  
  METHODS
  MNPs were synthesized as a core and coated with dextran as polymeric shell to provide steric stabilization. Curcumin as anticancer drug was selected to be loaded into NPs. To characterize the synthesized NPs, various techniques (e.g., DLS, FESEM, FT-IR, XRD, and VSM) were utilized. In vitro drug release of curcumin was evaluated at 37˚C at the pH value of 5.4 and 7.4.The feasibility of employment of dextran coated MNPs as MRI contrast agents were also studied.
  
  
  RESULTS
  Formulations prepared from dextran coated MNPs showed high loading (13%) and encapsulation efficiency (95%). In vitro release study performed in the phosphate-buffered saline (PBS, pH= 7.4, 5.4) revealed that the dextran coated MNPs possess sustained release behavior at least for 4 days with the high extent of drug release in acidic media. Vibrating sample magnetometer (VSM) analysis proved the superparamagnetic properties of the dextran coated MNPs with relatively high-magnetization value indicating that they were sufficiently sensitive to external magnetic fields as magnetic drug carriers. Furthermore, dextran coated MNPs exhibited high potential as T2 contrast agents for MRI.
  
  
  CONCLUSIONS
  Based on our findings, we propose the dextran coated MNPs as promising nanosystem for the delivery of various drugs such as curcumin and MRI contrast agent.
authors.affiliation: Department of Physics, University of Zanjan, Zanjan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Khalkhali
authors.affiliation: Department of Pharmaceutical Biomaterials, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Sadighian
authors.affiliation: Zanjan Pharmaceutical Nanotechnology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran ; Department of Medicinal Chemistry, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Kobra
authors.initials: K
authors.lastname: Rostamizadeh
authors.affiliation: Department of Physics, University of Zanjan, Zanjan, Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Khoeini
authors.affiliation: Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mehran
authors.initials: M
authors.lastname: Naghibi
authors.affiliation: Department of Pharmaceutical Biomaterials, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Nahid
authors.initials: N
authors.lastname: Bayat
authors.affiliation: Department of Pharmaceutical Biomaterials, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Mina
authors.initials: M
authors.lastname: Habibizadeh
authors.affiliation: Zanjan Pharmaceutical Nanotechnology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hamidi
keywords: Curcumin; Dextran; MRI contrast agent; Magnetic nanoparticles