title: Preparation of radioactive praseodymium oxide as a multifunctional agent in nuclear medicine:  expanding the horizons of cancer therapy using nanosized neodymium oxide.
abstract: OBJECTIVE
  Many studies have attempted to assess the significance of the use of the β(-)particle emitter praseodymium-142 ((142)Pr) in cancer treatment. As praseodymium oxide (Pr(2)O(3)) powder is not water soluble, it was dissolved in HCl solution and the resultant solution had to be pH adjusted to be in an injectable radiopharmaceutical form. Moreover, it was shown that the nanosized neodymium oxide (Nd(2)O(3)) induced massive vacuolization and cell death in non-small-cell lung cancer. In this work, the production of (142)Pr was studied and water-dispersible nanosized Pr(2)O(3) was proposed to improve the application of (142)Pr in nuclear medicine.
  
  
  METHODS
  Data from different databases pertaining to the production of (142)Pr were compared to evaluate the accuracy of the theoretical calculations. Water-dispersible nanosized Pr(2)O(3) was prepared using a poly(ethylene glycol) (PEG) coating or PEGylation method as a successful mode of drug delivery. Radioactive (142)Pr(2)O(3) was produced via a (142)Pr(n,γ)(142)Pr reaction by thermal neutron bombardment of the prepared sample.
  
  
  RESULTS
  There was good agreement between the reported experimental data and the data based on nuclear model calculations. In addition, a small part of nano-Pr(2)O(3) particles remained in suspension and most of them settled out of the water. Interestingly, the PEGylated Pr(2)O(3) nanoparticles were water dispersible. After neutron bombardment of the sample, a stable colloidal (142)Pr(2)O(3) was formed.
  
  
  CONCLUSIONS
  The radioactive (142)Pr(2)O(3) decays to the stable (142)Nd(2)O(3). The suggested colloidal (142)Pr(2)O(3) as a multifunctional therapeutic agent could have dual roles in cancer treatment as a radiotherapeutic agent using nanosized (142)Pr(2)O(3) and as an autophagy-inducing agent using nanosized (142)Nd(2)O(3).
authors.affiliation: Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. mk.bakht@gmail.com
authors.forename: Mohamadreza K
authors.initials: MK
authors.lastname: Bakht
authors.forename: Mahdi
authors.initials: M
authors.lastname: Sadeghi
authors.forename: Seyed J
authors.initials: SJ
authors.lastname: Ahmadi
authors.forename: Sodeh S
authors.initials: SS
authors.lastname: Sadjadi
authors.forename: Claudio
authors.initials: C
authors.lastname: Tenreiro
mesh_terms: D006801:Humans; D049329:Nanostructures / Q000737:chemistry* / Q000627:therapeutic use; D009354:Neodymium / Q000737:chemistry* / Q000627:therapeutic use; D009369:Neoplasms / Q000532:radiotherapy*; D009502:Neutrons; D009683:Nuclear Medicine / Q000379:methods*; D010087:Oxides / Q000737:chemistry* / Q000627:therapeutic use; D011221:Praseodymium / Q000737:chemistry* / Q000627:therapeutic use; D011854:Radiochemistry / Q000379:methods*; D011868:Radioisotopes / Q000737:chemistry* / Q000627:therapeutic use; D019275:Radiopharmaceuticals / Q000737:chemistry / Q000627:therapeutic use; D012995:Solubility; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D010087:Oxides; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D014867:Water; D009354:Neodymium; C505244:neodymium oxide; D011221:Praseodymium