PT - JOURNAL ARTICLE AU - Yamamoto, Fumihiko AU - Yamahara, Ryo AU - Kurihara, Kensuke AU - Tsukada, Hideo AU - Takeuchi, Eri AU - Hara, Isao AU - Makino, Akira AU - Kizaka-Kondoh, Shinae AU - Ozeki, Eiichi AU - Kimura, Shunsaku TI - Development and initial evaluation of novel fluorine-18 labeled nanocarrier "Lactosome" as a tumor imaging probe for PET DP - 2010 May 01 TA - Journal of Nuclear Medicine PG - 1509--1509 VI - 51 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/51/supplement_2/1509.short 4100 - http://jnm.snmjournals.org/content/51/supplement_2/1509.full SO - J Nucl Med2010 May 01; 51 AB - 1509 Objectives We have developed amphiphilic polydepsipeptide micelle "Lactosome" as a novel nanocarrier with tumor accumulation property by the enhanced permeability and retention effect for cancer imaging probes. We reported previously that a near infrared fluorescent (NIRF) imaging of mouse tumor with using ICG-lactosome. In this study, with aim of developing radiotracers for in vivo tumor imaging by PET, 18F-lactosome was synthesized and evaluated. Methods As a containable molecule into the lactosome, 18F labeled polylactic acid (18F-BzPLA) was synthesized in 20-37 % EOB by coupling reaction of SFB connected at an amino group terminal of polylactic acid. Micelle assemblies were prepared from a mixture of 18F-BzPLA and the amphiphilic polymer by a film method. For biodistribution studies, BALB/cA Jcl-nu/nu mice bearing HeLa cells in femur region were used. We took images by both PET and NIRF images of tumor bearing mice after co-injected 18F-lactosome with ICG-lactosome by using both Clairvivo PET and Clairvivo OPT (Shimadzu Corp. Japan) respectively. Results 18F-Lactosome was prepared in good yields (222-420 MBq). The radioactivity of 18F-lactosome was found to be stable in a blood circulation and maintained to higher level during 10 min to 6 hrs after injection. Tumor uptake increased gradually after injection. The mean uptake ratios of tumor/muscle, tumor/digestive tract and tumor/brain were 2.7, 2.8 and 4.9 at 6 hrs. In addition, tumor PET imaging of 18F-lactosome was capable and similar to NIRF imaging by ICG-lactosome. Conclusions Tumor imaging by PET with using lactosome as a nanocarrier is therefore a potential candidate for a facile and general tumor imaging technique