New work with exosomes promises wide-ranging advances in medicine, courtesy of an emerging biomolecular nanotechnology.
As pharmaceutical chemists know, the blood-brain barrier blocks delivery of many molecules that do wonderful things if injected directly into the brain, but injecting the brain isn’t quite as convenient as injecting a vein.
Exosomes are lipid vesicles manufactured by cells for transporting diverse molecules to other cells, including signaling molecules such as micro RNAs. Now, they’ve been shown to carry their contents across the blood-brain barrier, and other work has shown that exosome-like particles can be made synthetically, with membranes chock-full of functional molecules for targeting cells and inducing responses from them. With diameters of 30 to 100 nm, exosomes have room for a lot of payload.
BBC report here: “Breakthrough in delivering drugs to the brain”, abstract of paper in Nature Biotechnology here: “Delivery of siRNA to the mouse brain by systemic injection of targeted exosomes”.
The biomedical potential of siRNA is enormous, and delivery has been the main obstacle to wide-ranging applications.