Poly(L-lactic acid)-block-poly（sarcosine）両親媒性ポリデプシペプチドからなる放射性ヨウ素標識ナノキャリアの合成と担癌マウス及び炎症モデルマウスにおける生体内分布

We have developed amphiphilic polydepsipeptide micelle “lactosome” as a novel nanocarrier with tumor accumulation properties for cancer imaging probes. In this study, radioiodine-labeled lactosomes were synthesized and evaluated to develop diagnostic radiotracers for in vivo imaging utilizing single photon emission computed tomography (SPECT). The 125I-labeled lactosome was obtained in sufficient yields for biodistribution studies. Radioactivity in the blood circulation was maintained at a high level between 2–48 h post-injection of 125I-labeled lactosome into BALB/c mice. Radioactivity uptake by the Colon-26 tumor implanted in the femur gradually increased. The uptake ratio of subcutaneous tumor/muscle increased to 16.7 at 48 h post-injection. Additionally, tumor SPECT imaging of 123I-labeled lactosome in mice was achieved. Radioactivity uptake of turpentine-induced inflamed tissue reached a maximum at 24 h and then decreased at 48 h post-injection. The mean uptake ratio of inflammatory tissue/muscle increased to 14.4 at 24 h. In conclusion, radioiodine-labeled lactosomes as nanocarriers may serve as potential candidates in facile and generic tumor or inflammation imaging techniques.