Goins B, Phillips W T, Klipper R
Department of Radiology, University of Texas Health Science Center at San Antonio, Texas 78284-7800, USA.
J Nucl Med. 1996 Aug;37(8):1374-9.
This study evaluated two 99mTc-liposome formulations as potential blood-pool agents in comparison with standard 99mTc-red cells and 99mTc-human serum albumin (HSA).
Liposomes with no surface modification or coated with polyethylene glycol (PEG) were labeled with 99mTc using the lipophilic chelator, HMPAO. Autologous red cells were labeled with 99mTc using in vitro or in vivo techniques. Technetium-99m-HSA was supplied commercially. Rabbits were injected intravenously with 99mTc-liposomes, 99mTc-red cells or 99mTc-HSA. Static images were acquired and blood samples collected.
Technetium-99m-liposome images showed prominent blood-pool activity compared to lung and liver activities, which were similar to those acquired for 99mTc-red cells, but better than 99mTc-HSA. Heart-to-lung ratios were not significantly different between 99mTc-liposome formulations or for either formulation compared to 99mTc-red cells. The ratios were higher, however, than for 99mTc-HSA. Heart-to-liver ratios were higher for PEG 99mTc-liposomes than they were for neutral 99mTc-liposomes and 99mTc-HSA, but were not significantly different than 99mTc-red cells. Bladder activities for both 99mTc-liposome formulations were 3-6 times lower than for the other agents. PEG 99mTc-liposomes remained in circulation 1.6 times longer than any of the other agents.
Technetium-99m-liposomes, independent of surface modification, had excellent circulation persistence and in vivo stability when compared to 99mTc-red cells and 99mTc-HSA. PEG 99mTc-liposomes performed better than neutral 99mTc-liposomes due to lower liver background activity. Advantages of PEG 99mTc-liposomes compared to 99mTc-red cells include: (a) only one venipuncture, (b) little exposure to patient's blood, (c) excellent in vitro and in vivo stability and (d) lack of drug interference.
本研究评估了两种99mTc脂质体制剂作为潜在血池剂，并与标准的99mTc红细胞和99mTc人血清白蛋白（HSA）进行比较。
使用亲脂性螯合剂HMPAO将未进行表面修饰或涂有聚乙二醇（PEG）的脂质体用99mTc标记。自体红细胞采用体外或体内技术用99mTc标记。99mTc-HSA由商业供应。给兔子静脉注射99mTc脂质体、99mTc红细胞或99mTc-HSA。采集静态图像并收集血样。
与肺和肝脏活性相比，99mTc脂质体图像显示出显著的血池活性，这与99mTc红细胞获得的图像相似，但优于99mTc-HSA。99mTc脂质体制剂之间或与99mTc红细胞相比，任何一种制剂的心-肺比值均无显著差异。然而，该比值高于99mTc-HSA。PEG 99mTc脂质体的心-肝比值高于中性99mTc脂质体和99mTc-HSA，但与99mTc红细胞无显著差异。两种99mTc脂质体制剂的膀胱活性均比其他制剂低3至6倍。PEG 99mTc脂质体在循环中的停留时间比其他任何制剂长1.6倍。
与99mTc红细胞和99mTc-HSA相比，99mTc脂质体无论表面修饰如何，都具有出色的循环持久性和体内稳定性。PEG 99mTc脂质体由于较低的肝脏本底活性，表现优于中性99mTc脂质体。与99mTc红细胞相比，PEG 99mTc脂质体的优势包括：（a）只需一次静脉穿刺，（b）很少接触患者血液，（c）出色的体外和体内稳定性，以及（d）无药物干扰。
