Logo image
Novel Preparation Methods of Mn-52 for ImmunoPET Imaging
Journal article   Open access   Peer reviewed

Novel Preparation Methods of Mn-52 for ImmunoPET Imaging

Stephen A. Graves, Reinier Hemandez, Jesper Fonslet, Christopher G. England, Hector F. Valdovinos, Paul A. Ellison, Todd E. Barnhart, Dennis R. Elema, Charles P. Theuer, Weibo Cai, …
Bioconjugate chemistry, Vol.26(10), pp.2118-2124
10/01/2015
DOI: 10.1021/acs.bioconjchem.5b00414
PMCID: PMC4618027
PMID: 26317429
url
https://orbit.dtu.dk/en/publications/35d13ac3-98bb-47eb-ace9-6f61dad9a58fView
Open Access

Abstract

Mn-52 (t(1/2) = 5.59 d, beta(+) = 29.6%, E-beta ave = 0.24 MeV) shows promise in positron emission tomography (PET) and in dual-modality manganese-enhanced magnetic resonance imaging (MEMRI) applications including neural tractography, stem cell tracking, and biological toxicity studies. The extension to bioconjugate application requires high-specific-activity Mn-52 in a state suitable for macromolecule labeling. To that end a Mn-52 production, purification, and labeling system is presented, and its applicability in preclinical, macromolecule PET is shown using the conjugate Mn-52-DOTA-TRC105. Mn-52 is produced by 60 mu A, 16 MeV proton irradiation of natural chromium metal pressed into a silver disc support. Radiochemical separation proceeds by strong anion exchange chromatography of the dissolved Cr target, employing a semiorganic mobile phase, 97:3 (v:v) ethanol:HCl (11 M, aqueous). The method is 62 +/- 14% efficient (n = 7) in Mn-52 recovery, leading to a separation factor from Cr of (1.6 +/- 1.0) X 10(6) (n = 4), and an average effective specific activity of 0.8 GBq/mu mol (n = 4) in titration against DOTA. Mn-52-DOTA-TRC105 conjugation and labeling demonstrate the potential for chelation applications. In vivo images acquired using PET/CT in mice bearing 4T1 xenograft tumors are presented. Peak tumor uptake is 18.7 +/- 2.7%ID/g at 24 h post injection and ex vivo Mn-52 biodistribution validates the in vivo PET data. Free Mn-52(2+) (as chloride or acetate) is used as a control in additional mice to evaluate the nontargeted biodistribution in the tumor model.
Physical Sciences Biochemical Research Methods Biochemistry & Molecular Biology Chemistry Chemistry, Multidisciplinary Chemistry, Organic Life Sciences & Biomedicine Science & Technology

Details

Metrics

Logo image