^99mTc-Labeled Bevacizumab via HYNIC for Imaging of Melanoma
Pages 53-64
Ximena Camacho, María Fernanda García, Victoria Calzada, Marcelo Fernández, Omar Alonso, Juan Pablo Gambini, Rodrigo Barbosa de Aguiar, Camila Maria Longo Machado, Roger Chammas, Williams Porcal and Pablo Cabral
DOI: http://dx.doi.org/10.6000/1927-7229.2014.03.01.9
Published: 18 February 2014

Abstract: Vascular endothelial growth factor (VEGF) is one of the classic factors to tumour-induced angiogenesis in several types, including melanoma. Bevacizumab, a monoclonal antibody anti-VEGF, could be used as an imaging tool in clinical studies. The aim of this study was to radiolabeled Bevacizumab with ^99mTc and evaluate it in vivo imaging properties. Bevacizumab was derivatized with the activated ester succinimidyl-hydrazinonicotinamide hydrochloride (Suc-HYNIC) as a bifunctional coupling agent. A mixture of Tricine/SnCl₂.2H₂O was added to Bevacizumab-HYNIC and radiolabeled with ^99mTcO₄^-. The radiochemical stability of the radiolabeled sntibody was assessed. Biodistribution studies and SPECT-CT imaging were evaluated in healthy and tumor-bearing C57BL/6J mice at 1, 4 and 24 h (n =5). We demonstrated that ^99mTc-HYNIC-Bevacizumab was stable over 24 h in solution and serum. In vivo biodistribution studies revealed tumor-to-muscle ratios of ^99mTc-HYNIC-Bevacizumab was 9.28, 17.19 and 8.51 at 1, 4 and 24 h p.i. SPECT/CT imaging of tumor-bearing C57BL/6J mice showed tumor selective uptake of ^99mTc-HYNIC-Bevacizumab. ^99mTc-HYNIC-Bevacizumab could become a potential radiopharmaceutical to evaluate the expression of vascular endothelial growth factor (VEGF) in solid tumors and could be seen as a clinic tool for the screening of solid tumors that might respond to the Bevacizumab chemotherapy.