Feng L, Fang J, Zeng X, Liu H, Zhang J, Huang L, Guo Z, Zhuang R, Zhang X.
68Ga-Labeled Maleimide for Blood Pool and Lymph PET Imaging through Covalent Bonding to Serum Albumin In Vivo.
ACS OMEGA 2022;
7:28597-28604. [PMID:
35990434 PMCID:
PMC9386703 DOI:
10.1021/acsomega.2c03505]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
This study aims to develop a novel 68Ga-labeled tracer, which can covalently bind to albumin in vivo based on the maleimide-thiol strategy, and to evaluate its potential applications using positron emission tomography (PET). 68Ga-labeled maleimide-monoamide-DOTA (denoted as [68Ga]Ga-DM) was prepared conveniently with a high radiochemical yield (>90%) and radiochemical purity (>99%). Its molar activity was calculated as 249.60 ± 68.50 GBq/μmol, and the octanol-water partition coefficient (LogP) was -3.15 ± 0.08 with good stabilities. In vitro experiments showed that [68Ga]Ga-DM can bind to albumin efficiently and rapidly, with a binding fraction of over 70%. High uptake and excellent retention in blood were observed with a long half-life (t 1/2Z) of 190.15 ± 24.14 min, which makes it possible for blood pool PET imaging with high contrast. The transient micro-bleeding in the rat model was detected successfully with PET imaging. In addition, the uptakes of [68Ga]Ga-DM in the inflammatory popliteal lymph nodes depend on the severity (5.90% ID/g and 2.32% ID/g vs 1.01% ID/g for healthy lymph nodes at 0.5 h post-injection) indicating its feasibility for lymphatic imaging. In conclusion, a novel 68Ga-labeled tracer was prepared with high efficiency and yield in mild conditions. Based on the promising properties of bonding covalently to albumin, great stability, high blood contrast with a long half-life, and well environmental tolerance, [68Ga]Ga-DM could be developed as a potential tracer for PET imaging of blood pool, bleeding, and vascular permeability alteration diseases in the clinic.
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