Preparation of brain targeted immunoliposomes

To prepare a kind of effective non-viral transduction vector, which can deliver exogenous gene into the brain, this vector can be injected through vein system and has the ability to penetrate blood brain barrier.  Several groups of materials proportion, type of oil phase, water-oil ratio, phosphatides-cholestrol ratio, temperature of steaming, ultrasonic temperature and time were compared for optimization.  Well-constructed immunoliposomes encapsuling LacZ gene were infused into rats through tail vein.  48 h after injection, expression product beta- galactosidase of LacZ gene was detected by histochemistry staining to convince the validity of immunoliposomes as non-viral vectors.  The best proportion of synthesis immunoliposomes is as following: phosphatides-    cholestrol ratio is 1∶1, lipids/drug is 100∶1, the type of oil phrase is dichloromethane, oil-water ratio is 4∶1, temperature of steaming is 30 ℃, ultrasonic temperature and time is 10 ℃ and 5 min.  At last, 10% trehalose was added as a stabilizer.  The entrapment rate is 87.24% and antibody coupling rate is 69%.  When immunoliposomes were infused into rats, the expression of LacZ gene could be observed in the brain and periphery organs.  Through the best proportion of materials, gene delivering immunoliposomes had been synthesized successfully.  This non-viral vector can deliver exogenous gene penetrating blood brain barrier and express in the brain, and will be well-used in the field of gene therapy of cerebral diseases.