Current advances in vehicles for brain gene delivery

Gene therapy is a novel and promising treatment strategy for brain diseases. Yet, its development is largely obscured by various in vivo transport hurdles, especially the special BBB structure of brain. Developing an ingenious delivery vehicle can provide a great solution. Conventional vehicles for brain gene delivery are viral and non-viral vectors. With inherent superiority of gene transfection, researches on viral vectors are mainly focused on problems of brain cell targeting and global brain delivery. Non-viral vectors are more studied for better brain cell entrance either directly delivered to brain or systemically delivered to the body. Novel vehicles are cell vehicles (genetically engineered or nanoparticle- carrying cells) and exosomes. They exhibit distinct and unique features compared to viral and non-viral vectors. This review gives a summarization of current advances in these four kinds of brain gene vehicles. The merits and demerits of them are also pointed out respectively. We are hoping to give a clue to the future development direction of vehicles for brain gene delivery.