New coating improves penetration of therapeutic nanoparticles within the brain

BALTIMORE, MD – Scientists from Johns Hopkins University have discovered that using polyethylene glycol (PEG) to coat nanoparticles helped improve the penetration of nanoparticles through the brain’s extracellular space (ECS). The new development may open new possibilities for targeted drug delivery to the brain.

The study was published in Science Translational Medicine.

The brain’s ECS is a network of narrow channels within which fluids transport nutrients, signaling molecules, and other important particles throughout the brain. Its size limits the size of particles that can move through, which has been an obstacle in the use of nano-therapies in the brain.

The team from Johns Hopkins has been able to pass PEG-coated nanoparticles through the ECS nearly twice as big as before. The scientists discovered that besides the narrowness of the channels, a mechanism is involved that makes particles stick to the walls. A dense coating of PEG helped 114-nm particles glide through the ECS of mouse brains, a significant improvement over previously used 64 nm particles.

According to the authors in the study’s abstract, “The ability to achieve brain penetration with larger nanoparticles is expected to allow more uniform, longer-lasting, and effective delivery of drugs within the brain, and may find use in the treatment of brain tumours, stroke, neuroinflammation, and other brain diseases where the blood-brain barrier is compromised or where local delivery strategies are feasible.”