How to overcome the blood-brain barrier to deliver new medicines

Over the past several decades, significant strides have been made in discovering and developing new medicines for a wide range of conditions, from heart-related diseases and viral infections to certain types of cancer. 

The same cannot be said for diseases of the central nervous system (CNS), where significant need for new treatments remains. 

Nearly 47 million people are living with dementia¹ and there are millions of other people who have Parkinson’s disease, multiple sclerosis and other CNS diseases.² A number of potential approaches are emerging for finding new ways to cross the BBB without disrupting the brain’s functioning. Here are three of them:

Anamarija Curic, Ph.D., senior research scientist in the chemical entity formulation group in AbbVie Germany, is part of a team exploring the use of nanoparticles in new methods of drug delivery.

Nanoparticles are tiny particles that can’t be seen under a standard light microscope. For an idea of size, the particles measure 1 to 100 nanometers. For comparison, a single bacterium measures approximately 1,000 nanometers, while a tennis ball is 100 million nanometers.

The role of nanoparticles is to transport, something scientists are trying to put to use in drug research.

“Think of nanoparticles like taxi cabs with GPS on the surface, driving their passenger, a therapeutic medicine, directly into the brain,” Curic explains. “Our mission is to develop nanoparticles that could carry small molecules or biologics as their passengers, with controlled release in the diseased tissue.”

The promise of this approach has attracted the interest of companies and academic centers. AbbVie leads the BBB work stream of a large public-private partnership known as COMPACT, part of the Innovative Medicines Initiative (IMI). Nanotechnology is one key area of research being explored through this collaboration.

In another novel approach, scientists are using protein capsules to package drug molecules into tiny, micro-containers and take them across the BBB into the central nervous system. 

These tiny packages can be thought of like a “Trojan horse” – carrying something into the brain that previously was unable to pass through on its own, and bringing it straight to the diseased tissue. 

This direct targeting of the medicine also allows for smaller doses to be given to patients. AbbVie is exploring this exciting area of technology through a project co-funded by a grant from the Germany Ministry for Education and Research and in collaboration with another biotech company. 

“Given the number of different disease targets in the brain, it’s clear that a one-size-fits-all approach is not going to work,” Hahn says. “Pursuing a number of innovative new approaches to crossing the BBB gives us the best chance for being successful in helping patients.”

¹ https://alz.org/global/
² https://www.mstrust.org.uk/a-z/prevalence-and-incidence-multiple-sclerosis