2018年7月
Urokinase injection-triggered clearance enhancement of a 4-arm PEG-conjugated Cu-64-bombesin analog tetramer: A novel approach for the improvement of PET imaging contrast
INTERNATIONAL JOURNAL OF PHARMACEUTICS
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- 巻
- 545
- 号
- 1-2
- 開始ページ
- 206
- 終了ページ
- 214
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1016/j.ijpharm.2018.05.014
- 出版者・発行元
- ELSEVIER SCIENCE BV
Radiolabeled antibodies, polyethylene glycol-conjugated (PEGylated) peptides, liposomes, and other materials were investigated as positron-emission tomography (PET) probes. These substances accumulate in tumors but often remain too long in circulation. We investigated the combination of intravenous urokinase injection and its substrate linker as a triggered radioisotope clearance enhancement system to improve imaging contrast. To this end, we synthesized a four-arm PEGylated Cu-64-bombesin analog tetramer with a urokinase substrate linker. In mouse blood, it was almost perfectly cleaved and degraded into smaller radioactive fragments in vitro with urokinase (>= 20,000 IUmL). In mouse blood circulation, similar to 50-65% of the probe was rapidly degraded after the urokinase injection and the radioactive fragments were eliminated mainly from the kidney. In contrast, tumor radioactivity levels did not change, and therefore, the tumors were clearly visualized. The tumor/blood ratio, an indicator of imaging contrast, increased 2.5 times, while elimination of the radioisotope from the blood was enhanced. This approach has the potential to improve imaging contrast using various PET probes. It could also shorten the time required to obtain sufficient contrast and decrease patient radiation exposure.
- リンク情報
- ID情報
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- DOI : 10.1016/j.ijpharm.2018.05.014
- ISSN : 0378-5173
- eISSN : 1873-3476
- PubMed ID : 29746998
- Web of Science ID : WOS:000433411000024