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内容記述 |
Background: A family of BF2-chelated tetraaryl-azadipyrromethenes was developed as non-porphyrin photosensitizers for photodynamic therapy. Among the developed photosensitizers, ADPM06 exhibited excellent photochemical and photophysical properties. Molecular imaging is a useful tool for photodynamic therapy planning and monitoring. Radiolabeled photosensitizers can efciently address photosensitizer biodistribution, providing helpful information for photodynamic therapy planning. To evaluate the biodistribution of ADPM06 and predict its pharmacokinetics on photody?namic therapy with light irradiation immediately after administration, we synthesized [18F]ADPM06 and evaluated its in vivo properties.
Results: [18F]ADPM06 was automatically synthesized by Lewis acid-assisted isotopic 18F19F exchange using ADPM06 and tin (IV) chloride at room temperature for 10 min. Radiolabeling was carried out using 0.4 μmol of ADPM06 and 200 μmol of tin (IV) chloride. The radiosynthesis time was approximately 60 min, and the radiochemi?cal purity was>95% at the end of the synthesis. The decay-corrected radiochemical yield from [18F]F? at the start of synthesis was 13±2.7% (n=5). In the biodistribu?tion study of male ddY mice, radioactivity levels in the heart, lungs, liver, pancreas, spleen, kidney, small intestine, muscle, and brain gradually decreased over 120 min after the initial uptake. The mean radioactivity level in the thighbone was the high?est among all organs investigated and increased for 120 min after injection. Upon co-injection with ADPM06, the radioactivity levels in the blood and brain signifcantly increased, whereas those in the heart, lung, liver, pancreas, kidney, small intestine, muscle, and thighbone of male ddY mice were not afected. In the metabolite analysis of the plasma at 30 min post-injection in female BALB/c-nu/nu mice, the percent?age of radioactivity corresponding to [18F]ADPM06 was 76.3±1.6% (n=3). In a posi?tron emission tomography study using MDA-MB-231-HTB-26 tumor-bearing mice (female BALB/c-nu/nu), radioactivity accumulated in the bone at a relatively high level and in the tumor at a moderate level for 60 min after injection. |
