Christiaan A. Gouws, Tricia Naicker, Beatriz G. de la Torre, Fernando Albericio, Janie Duvenhage, Hendrik G. Kruger, Biljana Marjanovic-Painter, Sipho Mdanda, Jan R. Zeevaart, Thomas Ebenhan, Thavendran Govender
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引用次数: 0
Abstract
This research presents the development of positron emission tomography (PET) radiotracers for detecting Mycobacterium tuberculosis (MTB) for the diagnosis and monitoring of tuberculosis. Two phage display–derived peptides with proven selective binding to MTB were identified for development into PET radiopharmaceuticals: H8 (linear peptide) and PH1 (cyclic peptide). We sought to functionalize H8/PH1 with NODASA, a bifunctional chelator that allows complexation of PET-compatible radiometals such as gallium-68. Herein, we report on the chelator functionalization, optimized radiosynthesis, and assessment of the radiopharmaceutical properties of [68Ga]Ga-NODASA-H8 and [68Ga]Ga-NODASA-PH1. Robust radiolabeling was achieved using the established routine method, indicating consistent production of a radiochemically pure product (RCP ≥ 99.6%). For respective [68Ga]Ga-NODASA-H8 and [68Ga]Ga-NODASA-PH1, relatively high levels of decay-corrected radiochemical yield (91.2% ± 2.3%, 86.7% ± 4.0%) and apparent molar activity (Am, 3.9 ± 0.8 and 34.0 ± 5.3 GBq/μmol) were reliably achieved within 42 min, suitable for imaging purposes. Notably, [68Ga]Ga-NODASA-PH1 remained stable in blood plasma for up to 2 h, while [68Ga]Ga-NODASA-H8 degraded within 30 min. For both 68Ga peptides, minimal whole-blood cell binding and plasma protein binding were observed, indicating a favorable pharmaceutical behavior. [68Ga]Ga-NODASA-PH1 is a promising candidate for further in vitro/in vivo evaluation as a tuberculosis-specific infection imaging agent.
期刊介绍:
The Journal of Labelled Compounds and Radiopharmaceuticals publishes all aspects of research dealing with labeled compound preparation and applications of these compounds. This includes tracer methods used in medical, pharmacological, biological, biochemical and chemical research in vitro and in vivo.
The Journal of Labelled Compounds and Radiopharmaceuticals devotes particular attention to biomedical research, diagnostic and therapeutic applications of radiopharmaceuticals, covering all stages of development from basic metabolic research and technological development to preclinical and clinical studies based on physically and chemically well characterized molecular structures, coordination compounds and nano-particles.