A new polymer-based approach for in vivo transfection in postnatal brain

Gene delivery within the central nervous system at postnatal age is one of the most challenging tasks in neuroscience and currently only a few effective methods are available.

For postnatal central nervous system cells, viral approaches are commonly used for genetic engineering but they face several biosafety requirements for production and use making them less accessible to the community. Conversely, lipid-based methods are widely used in cell culture but face limitation in vivo mainly due to the inflammatory responses they induce. To this aspect, the use of a transgenic mouse line can represent a credible answer to the community working on rat models still requires an effective and successful solution to circumvent these difficulties.

We describe a new polymer-based gene delivery system allowing persistent and robust in vivo transfection with low DNA amount, reduced inflammation and high diffusion. The expression profile along the brain, the stability, the diffusion of the DNA together with the quantity of cells transfected were evaluated through in vivo approaches.

With a single low-volume injection, we targeted different cell types within the rat brain. We measured the diffusion rate ranging from 1 to 5 mm based on the injected volume, in the three-dimensions axis. Finally, we modified brain susceptibility to epileptic seizures using a specific knock-down of the neuronal specific potassium-chloride transporter 2.

This safe and easy system opens perspectives for non viral gene delivery in the rat brain with perspectives to study brain function in vivo.