Treatment of neurological disorders, such as Parkinson’s disease and stroke, has always been a challenging task, partly due to the existence of the blood-brain barrier (BBB). The BBB is a border that separates the blood circulation from the surrounding brain tissue. In a healthy brain, the BBB only allows the passage of nutrients crucial to brain function, while restricting the transportation of other substances, including drugs that might be vital for improving brain health. To address this issue, scientists from Cedars-Sinai Medical Center have developed a nanoconjugate platform that can carry drugs and cross the BBB in healthy mouse brain.

The nanoconjugate platform is made of three major components: 1) a polymer scaffold that functions as the carrier, 2) a peptide molecule that was known for its ability to cross the BBB, and 3) agents for stabilizing the structure and assisting in drug transportation. The polymer carrier is biodegradable, meaning that it can dissolve in the brain to release the cargo. Experiments in this study shown that the nanoconjugate platform can readily cross the BBB and reach the brain tissue in mice. Additionally, the drug delivery capabilities can be compromised if any of the major components is removed.

The authors suggested that they will further improve the specificity of the drug delivery platform by adding molecules that have high affinity with different cell types in the brain. In addition, their results showed that the nanoconjugate concentration is higher in the regions with dense blood vessels. Therefore, controlling drug delivery selectively into disease-affected regions (with a lower density of blood vessels) is another challenge to address in the future.

Managing Correspondent: Anqi Zhang

Original journal article: A Combination of Tri-Leucine and Angiopep‑2 Drives a Polyanionic Polymalic Acid Nanodrug Platform Across the Blood−Brain Barrier. ACS Nano.

Image Credit: Drug Target Review