Kitamura Naoto, Shigematsu Naoyuki, Nakahara Tadaki, Kanoh Momoe, Hashimoto Jun, Kunieda Etsuo, Kubo Atsushi
Department of Radiology, Keio University, School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
Ann Nucl Med. 2009 Feb;23(2):149-53. doi: 10.1007/s12149-008-0222-4. Epub 2009 Feb 19.
Immunoliposome (PEG, GAH, liposome; PGL), consisting of F(ab')(2) fragment of monoclonal antibody, GAH and polyethyleneglycol-coated (PEGylated) liposome was provided. Immunoliposome, PGL was labeled with technetium-99m (Tc-99m) by two methods: labeling F(ab')(2) fragment with Tc-99m; Tc-99m-PGL, and entrapping Tc-99m into liposome; PGL[Tc-99m]. The objective of this study was to compare the biodistribution of Tc-99m-PGL and PGL[Tc-99m] in human gastric cancer xenografted mice.
Tc-99m-PGL, PGL[Tc-99m], and Tc-99m-entrapped liposome; Lipo[Tc-99m] were prepared. They were injected into human gastric cancer, MKN45, xenografted mice via the tail vein, and their biodistribution was studied.
No marked accumulation of either PGL[Tc-99m] or Lipo[Tc-99m] was observed in the stomach. The uptake of Tc-99m-PGL by the liver, spleen, and lung was higher than that by the tumor. On the other hand, the uptake of PGL[Tc-99m] by the lung and spleen was markedly lower as compared with that of Tc-99m-PGL; the accumulation of PGL[Tc-99m] was lower in the lung and higher in the spleen as compared with that of the tumor. Although the liver uptake of PGL[Tc-99m] was markedly decreased as compared with that of Tc-99m-PGL, it was higher than the uptake of the tumor. The Tc-99m-PGL was strongly taken up by the tumor, with a high level of incorporation also seen in the stomach. These findings suggest the need for further study of the labeling stability.
PGL[Tc-99m] appears to show promise for high tumor uptake and retention. This is an important implication for the potential application of immunoliposomes entrapped with Re-186, instead of Tc-99m, in internal radiotherapy.
制备由单克隆抗体的F(ab')(2)片段、GAH和聚乙二醇包被（聚乙二醇化）脂质体组成的免疫脂质体（PEG、GAH、脂质体；PGL）。免疫脂质体PGL通过两种方法用锝-99m（Tc-99m）标记：用Tc-99m标记F(ab')(2)片段；Tc-99m-PGL，以及将Tc-99m包封到脂质体中；PGL[Tc-99m]。本研究的目的是比较Tc-99m-PGL和PGL[Tc-99m]在人胃癌异种移植小鼠中的生物分布。
制备Tc-99m-PGL、PGL[Tc-99m]和包封Tc-99m的脂质体；Lipo[Tc-99m]。通过尾静脉将它们注射到人胃癌MKN45异种移植小鼠中，并研究它们的生物分布。
在胃中未观察到PGL[Tc-99m]或Lipo[Tc-99m]有明显蓄积。肝脏、脾脏和肺对Tc-99m-PGL的摄取高于肿瘤。另一方面·与Tc-99m-PGL相比，肺和脾脏对PGL[Tc-99m]的摄取明显较低；与肿瘤相比，PGL[Tc-99m]在肺中的蓄积较低，在脾脏中的蓄积较高。虽然与Tc-99m-PGL相比，肝脏对PGL[Tc-99m]的摄取明显降低，但仍高于肿瘤的摄取。Tc-99m-PGL被肿瘤强烈摄取，在胃中也有高水平的摄取。这些发现表明需要进一步研究标记稳定性。
PGL[Tc-99m]似乎显示出高肿瘤摄取和滞留的前景。这对于用Re-186而非Tc-99m包封的免疫脂质体在体内放射治疗中的潜在应用具有重要意义。
