The blood-brain barrier is an extremely tight cellular structure, perhaps even too tight. While it prevents bacteria, viruses and dangerous foreign molecules from moving from the blood to the brain, it also impedes the delivery of drugs to treat neurodegenerative diseases such as Alzheimer’s and Parkinson’s. It is estimated that only 2% of therapeutic substances are able to cross it freely.

In the hope of better circumventing this barrier, researchers are studying it using models created from human or animal brain cells that have been altered to make them immortal. However, these models have many disadvantages, particularly with regard to the reproducibility of results. This is what prompted Valérie Gaëlle Roullin, a professor in the Faculty of Pharmacy at the Université de Montréal, to develop a more reliable in vitro model that better reproduces the complexity of a whole brain.

The researcher and her team used cells extracted directly from the brains of mice to generate a novel model in just 10 days, whereas it normally takes weeks to achieve this. Furthermore, this model is more accessible, since the protocol for its production requires little specialized analysis equipment, among other things.

This new cellular model has proven to be 80% reliable for determining what happens at the blood-brain barrier when drugs attempt to cross it under healthy conditions, compared with 40% for pre-existing models. In addition, it dispels the idea that inflammation alters the permeability of the blood-brain barrier, thereby significantly affecting the passage of therapeutic molecules. This work helps pave the way for the development of a new generation of more bioavailable drugs in the future.