Mass spectrometry characterization of DOTA-Nimotuzumab conjugate as precursor of an innovative β- tracer suitable in radio-guided surgery

Claudia Martelli; Valeria Marzano; Federica Marini; Teresa Scotognella; Ilaria Fratoddi; Iole Venditti; Dante Rotili; Elena Solfaroli-Camillocci; Francesco Collamati; Carlo Mancini-Terracciano; Silvio Morganti; Daria Maccora; Riccardo Faccini; Antonella Cartoni; Alessandro Giordano; Massimo Castagnola

doi:10.1016/j.jpba.2018.03.018

Mass spectrometry characterization of DOTA-Nimotuzumab conjugate as precursor of an innovative β^- tracer suitable in radio-guided surgery

J Pharm Biomed Anal. 2018 Jul 15:156:8-15. doi: 10.1016/j.jpba.2018.03.018. Epub 2018 Mar 12.

Authors

Claudia Martelli¹, Valeria Marzano¹, Federica Marini¹, Teresa Scotognella², Ilaria Fratoddi³, Iole Venditti³, Dante Rotili⁴, Elena Solfaroli-Camillocci⁵, Francesco Collamati⁶, Carlo Mancini-Terracciano⁶, Silvio Morganti⁶, Daria Maccora², Riccardo Faccini⁷, Antonella Cartoni⁸, Alessandro Giordano², Massimo Castagnola⁹

Affiliations

¹ Institute of Biochemistry and Clinical Biochemistry, Catholic University, Largo F. Vito 1, 00168, Rome, Italy.
² Institute of Nuclear Medicine, Catholic University, Largo A. Gemelli 8, 00168, Rome, Italy.
³ Department of Chemistry, Sapienza University, P.le Aldo Moro 5, 00185, Rome, Italy.
⁴ Department of Chemistry and Technology of Drugs, Sapienza University, P.le Aldo Moro 5, 00185, Rome, Italy.
⁵ Department of Physics, Sapienza University, P.le Aldo Moro 5, 00185, Rome, Italy.
⁶ INFN, P.le Aldo Moro 5, 00185, Rome, Italy.
⁷ Department of Physics, Sapienza University, P.le Aldo Moro 5, 00185, Rome, Italy; INFN, P.le Aldo Moro 5, 00185, Rome, Italy.
⁸ Department of Chemistry, Sapienza University, P.le Aldo Moro 5, 00185, Rome, Italy. Electronic address: antonella.cartoni@uniroma1.it.
⁹ Institute of Biochemistry and Clinical Biochemistry, Catholic University, Largo F. Vito 1, 00168, Rome, Italy; Institute of Chemistry of Molecular Recognition, CNR, Largo F. Vito 1, 00168, Rome, Italy.

PMID: 29704772
DOI: 10.1016/j.jpba.2018.03.018

Abstract

The aim of the present work has been the mass spectrometry characterization of the Nimotuzumab (NIM) antibody chemically modified with the bifunctional chelating agent para-S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza cyclododecanetetraacetic acid (p-SCN-Bn-DOTA). The conjugate, upon labeling with the pure β^--emitter ⁹⁰Y³⁺_, could represent a promising candidate as radiotracer for an innovative radio-guided surgery (RGS) technique, developed and patented by researchers of our group, which uses a probe system for intraoperative detection of tumor residues exploiting the selective uptake of β^--emitting tracers. The results reported in this study show that multiple DOTA molecules bind to lysine residues of both light and heavy chains of the antibody and, probably, some of them are linked to the variable region of antibody. Moreover, the new mass spectrometric analysis highlights the presence of unreacted NIM in the final product. The information obtained by this work is of fundamental importance in the perspective to utilize this conjugate as a radiocompound after its labeling with ⁹⁰Y³⁺ radioisotope. Indeed, the conjugation efficiency and the presence of unreacted NIM affect the specific activity of the final radiotracer which binds specific receptor.

Keywords: Conjugate; Mass spectrometry; Monoclonal antibodies; Radio-guided surgery; Tumor resection.

MeSH terms

Antibodies, Monoclonal, Humanized / analysis*
Antibodies, Monoclonal, Humanized / chemistry
Chelating Agents / chemistry*
Heterocyclic Compounds / chemistry*
Immunoconjugates / analysis*
Immunoconjugates / chemistry
Isothiocyanates / chemistry*
Mass Spectrometry / instrumentation
Mass Spectrometry / methods
Radioactive Tracers
Surgery, Computer-Assisted / methods*
Yttrium Radioisotopes

Substances

2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid
Antibodies, Monoclonal, Humanized
Chelating Agents
Heterocyclic Compounds
Immunoconjugates
Isothiocyanates
Radioactive Tracers
Yttrium Radioisotopes
Yttrium-90
nimotuzumab