中文摘要：

目的：研究脂质体对神经生长因子（NGF）包裹后促进其通过血脑屏障（BBB）的作用。方法：将^99mTc-NGF用脂质体包裹后，按照以下条件处理：将包裹含有4．0mCi^99mTc-NGF的脂质体。注射至新西兰兔体内，利用SPECT分析其在脑部分布的百分数，对照组以相同放射剂量的^99mTc-NGF、^99mTc-NGF普通脂质体。处理用来考察脑组织靶向性；同时以0.05mg／kg剂量将NGF脂质体。单纯NGF、空白脂质体、生理盐水分别注入新西兰兔体内，利用ELISA法于30、60、90、120min测定脑脊液中NGF的浓度。结果：自制注射用脂质体。组包裹的^99mTc-NGF经SPECT显像，其在脑部的放射性计数较高，而^99mTc-NGF组几乎全部从泌尿系统代谢、^99mTc-NGF普通脂质体。组基本被网状内皮系统吞噬后沉积于肝脏；ELISA检测证明脂质体包裹的NGF能够部分通过血脑屏障。结论：此自制NGF-脂质体。具有一定的脑组织靶向性，能够携带NGF通过BBB。

英文摘要：

Objective：To research the penetration to blood brain barrier（BBB） after nerve growth factor（NGF） packed with liposome. Methods：The 4.0mCi of ^99mTc-NGF packed with liposomeA,4.0mCi of ^99mTc-NGF packed with liposomeB and free ^99mTc-NGF were in- jected into the rabbit by the vein of ear border respectively. SPECT was used to detect the distribution of ^99mTc-NGF. And then the ratio of radioactivity counts were calculated to describe the character of distribution in brain;The NGF concentration in CSF was detected by ELISA after the NGF was injected into the rabbit at 30,60,90,120 min. Results：The results of imaging with SPECT showed that ^99mTc-NGF packed with liposomeA was aggregated in brain; while ^99mTc-NGF was evacuated through urinary system. In addition, ^99mTc-NGF packed with liposomeB was aggregated in liver;The NGF concentration in CSF showed that the NGF packed with liposome could penetrate the BBB partly. Conclusion：The ratio of brain tissue signal intensity to body signal intensity of NGF packed with liposomeA obviously exceeded that of NGF and liposomes from beginning to terminal. The NGF packed with liposomeA could help the NGF penetration the BBB.