Dedicated distribution of nerve growth factor in different forms / 中国组织工程研究

ABSTRACT

BACKGROUND: That the nerve growth factor(NGF) is capable of treating peripheral nerve injury has been broadly acknowledged. But it is not sure whether it is able to pass through blood brain barrier(BBB) to act on central nerve system. In this study, the NGF encapsulated in liposome was compared with NGF alone in their abilities of passing through BBB.OBJECTIVE: To compare the dedicated distribution of NGF in different forms using single photon emission computerized tomography(SPECT).DESIGN: It is a randomized controlled study with New Zealand rabbits as subject.SETTING: An affiliated hospital of Nanjing Medical College.MATERIALS:The trial was conducted in Nanjing Senke Medical Company and the Nuclear Medicine Department of the First Hospital of Nanjing Medical College from June 2003 to May 2004. The subjects were 19 New Zealand rabbits of either sex, weighting (2.0 ±0. 2) kg, from Anlimo Technology Company. [99Tcm] -NGF(labeling rate 98.9%, purity 99.7% )was made by Senke Medical Company. Liposome was provided by Shengyang Pharmaceutical College. Urethine solution(200 g/L) was from Pharmacy Department of NanJing Medical Collage.METHODS: [99Tcm]-NGF was encapsulated in liposome and was treated as the following: The liposomesA containing 1.48 × 108Bq[99Tcm] -NGF were injected into rabbits and its distribution percentage was analyzed with SPECT. The same amounts of[99Tcm] -NGF and[99Tcm] -NGF-ordinary liposomesB were treated in the same way.MAIN OUTCOME MEASURES: The ratio of concentration and radiation percentage of NGF in brain to those in the whole body.RESULTS: The[99Tcm]-NGF encapsulated in self-made liposomeA presented high radiation in the brain. But[99Tcm] -NGF alone was almost completely excreted through urinary system and[99Tcm] -NGF encapsuled in ordinary liposomeB was mostly phagocytized by liver reticuloendothelial system.CONCLUSION: The self-made NGF-liposomeA is brain-dedicated, which set a basis for drugs to pass through BBB.