Preparation of radioactive praseodymium oxide as a multifunctional agent in nuclear medicine: expanding the horizons of cancer therapy using nanosized neodymium oxide

Objective Many studies have attempted to assess the significance of the use of the beta(-)-particle emitter praseodymium-142 (Pr-142) in cancer treatment As praseodymium oxide (Pr2O3) powder is not water soluble, it was dissolved in HCI 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 (Nd2O3) induced massive vacuolization and cell death in non-small-cell lung cancer. In this work, the production of Pr-142 was studied and waterdispersible nanosized Pr2O3 was proposed to improve the application of Pr-142 in nuclear medicine. Materials and methods Data from different databases pertaining to the production of Pr-142 were compared to evaluate the accuracy of the theoretical calculations. Water-dispersible nanosized Pr2O3 was prepared using a poly(ethylene glycol) (PEG) coating or PEGylation method as a successful mode of drug delivery. Radioactive (Pr2O3)-Pr-142 was produced via a Pr-141(n,gamma)Pr-142 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-Pr2O3 particles remained in suspension and most of them settled out of the water. Interestingly, the PEGylated Pr2O3 nanoparticles were water dispersible. After neutron bombardment of the sample, a stable colloidal (Pr2O3)-Pr-142 was formed. Conclusion The radioactive (Pr2O3)-Pr-142 decays to the stable (Nd2O3)-Nd-142. The suggested colloidal (Pr2O3)-Pr-142 as a multifunctional therapeutic agent could have dual roles in cancer treatment as a radiotherapeutic agent using nanosized (Pr2O3)-Pr-142 and as an autophagy-inducing agent using nanosized (Nd2O3)-Nd-142. Nud Med Commun 34:5-12 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins. Nuclear Medicine Communications 2013, 34:5-12