Table of Contents Author Guidelines Submit a Manuscript
Journal of Nanomaterials
Volume 2016 (2016), Article ID 1039258, 11 pages
http://dx.doi.org/10.1155/2016/1039258
Research Article

177Lu-Dendrimer Conjugated to Folate and Bombesin with Gold Nanoparticles in the Dendritic Cavity: A Potential Theranostic Radiopharmaceutical

1Instituto Nacional de Investigaciones Nucleares (ININ), 52750 Ocoyoacac, MEX, Mexico
2Universidad Autónoma del Estado de México, 50180 Toluca, MEX, Mexico

Received 15 April 2016; Revised 28 June 2016; Accepted 29 June 2016

Academic Editor: Piersandro Pallavicini

Copyright © 2016 Héctor Mendoza-Nava et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

177Lu-labeled nanoparticles conjugated to biomolecules have been proposed as a new class of theranostic radiopharmaceuticals. The aim of this research was to synthesize 177Lu-dendrimer(PAMAM-G4)-folate-bombesin with gold nanoparticles (AuNPs) in the dendritic cavity and to evaluate the radiopharmaceutical potential for targeted radiotherapy and the simultaneous detection of folate receptors (FRs) and gastrin-releasing peptide receptors (GRPRs) overexpressed in breast cancer cells. p-SCN-Benzyl-DOTA was conjugated in aqueous-basic medium to the dendrimer. The carboxylate groups of Lys1Lys3(DOTA)-bombesin and folic acid were activated with HATU and also conjugated to the dendrimer. The conjugate was mixed with 1% HAuCl4 followed by the addition of NaBH4 and purified by ultrafiltration. Elemental analysis (EDS), particle size distribution (DLS), TEM analysis, UV-Vis, and infrared and fluorescence spectroscopies were performed. The conjugate was radiolabeled using 177LuCl3 or 68GaCl3 and analyzed by radio-HPLC. Studies confirmed the dendrimer functionalization with high radiochemical purity (>95%). Fluorescence results demonstrated that the presence of AuNPs in the dendritic cavity confers useful photophysical properties to the radiopharmaceutical for optical imaging. Preliminary binding studies in T47D breast cancer cells showed a specific cell uptake (%). 177Lu-dendrimer(AuNP)-folate-bombesin may be useful as an optical and nuclear imaging agent for breast tumors overexpressing GRPR and FRs, as well as for targeted radiotherapy.