Title:Transient Opening of the Blood-Brain Barrier by Vasoactive Peptides to
Increase CNS Drug Delivery: Reality Versus Wishful Thinking?
Volume: 20
Issue: 7
Author(s): Matthew A. Smith-Cohn*, Nicholas B. Burley and Stuart A. Grossman*
Affiliation:
- Ben & Catherine Ivy Center for Advanced Brain Tumor Treatment, Swedish Neuroscience Institute, Seattle, WA, USA
- Department of Oncology, Sidney
Kimmel Comprehensive Cancer Center, Baltimore, MD, USA
Keywords:
Blood-brain barrier, vasoactive peptides, pharmacokinetics, neurology, neuro-oncology, drug delivery, oncology, metastasis.
Abstract:
Background: The blood-brain barrier inhibits the central nervous system penetration of
98% of small molecule drugs and virtually all biologic agents, which has limited progress in treating
neurologic disease. Vasoactive peptides have been shown in animal studies to transiently disrupt the
blood-brain barrier and regadenoson is currently being studied in humans to determine if it can improve
drug delivery to the brain. However, many other vasoactive peptides could potentially be used
for this purpose.
Methods: We performed a review of the literature evaluating the physiologic effects of vasoactive
peptides on the vasculature of the brain and systemic organs. To assess the likelihood that a vasoactive
peptide might transiently disrupt the blood-brain barrier, we devised a four-tier classification
system to organize the available evidence.
Results: We identified 32 vasoactive peptides with potential blood-brain barrier permeabilityaltering
properties. To date, none of these are shown to open the blood-brain barrier in humans.
Twelve vasoactive peptides increased blood-brain barrier permeability in rodents. The remaining 20
had favorable physiologic effects on blood vessels but lacked specific information on permeability
changes to the blood-brain barrier.
Conclusion: Vasoactive peptides remain an understudied class of drugs with the potential to increase
drug delivery and improve treatment in patients with brain tumors and other neurologic diseases.
Dozens of vasoactive peptides have yet to be formally evaluated for this important clinical effect.
This narrative review summarizes the available data on vasoactive peptides, highlighting
agents that deserve further in vitro and in vivo investigations.