Delivery of siRNA across the blood brain barrier .. Need Help !!

Hi! my supervisor wants me to use exosomes in our model and I am trying to follow the method of Nat. Protocols El-Andaloussi et al 2012 and Alvarez-Erviti Nat Biotech 2011 but I am not getting any silencing in the brain and I have just seen these comments in you tube and in this blog talking about fraud and saying that this papers should be retracted! who should I trust? does anybody know other protocol for brain delivery of siRNAs using exosomes? I am quite desperate! any advice would be greatly appreciated!

http://www.youtube.com/watch?v=Ry9kL-R-7E8
http://metamodern.com/2011/03/22/across-...-exosomes/

Cheers
Ana