The blood-brain barrier (BBB) protects the brain, acting as a biological gatekeeper, preventing harmful substances from entering its ecosystem. However, it also restricts access to vital therapeutics, limiting treatment options for neurological problems. To solve this issue, a new technique for unlocking the brain with microbubbles and ultrasound is being developed.
A worldwide team of researchers, led by Georgia Tech biomedical engineer Costas Arvanitis, addresses the difficulty with a technique that blends microbubbles (small gas-filled spheres) and ultrasonic technology. Their novel strategy hopes to temporarily access the BBB, allowing medications or immune cells to combat disease and provide therapeutic hope to patients suffering from disorders such as brain cancer or Alzheimer’s disease.
Arvanitis, associate professor in the Wallace H. Coulter Department of Biomedical Engineering said
We found that microbubble-enhanced ultrasound, an emerging technology that offers a noninvasive way to temporarily open the blood-brain barrier, allows blood-borne therapeutics to reach the brain,”
Bouncing Bubbles
Microbubbles are smaller than human hair and feature lipid or protein shells. In health care, they are frequently employed to improve ultrasound visibility by serving as contrast agents and revealing information inside the body.
Ultrasound creates images by using high-frequency sound pulses. When exposed to concentrated ultrasound waves, microbubbles quickly expand and contract. This modest mechanical force disturbs the protective barrier around the brain, leaving microscopic gaps for assistance to enter through.
Arvanitis further said
Despite their simple structure, microbubbles have complex behaviors. They can resonate at specific frequencies, allowing us to manipulate their oscillations to enhance permeability at the blood-brain barrier. And their behavior also depends on their size and shell composition.
Researchers used a mathematical model to simulate microbubble dynamics in brain vessels, identifying a resonant frequency that enhances microbubble movement. They found ultrasound frequencies can enhance immune cell movement, increase drug accumulation in brain tumors, and increase inflammatory markers, causing complications in neurological disorders.
The findings could lead to novel diagnostic methods and have ramifications beyond medication distribution. By breaking through the blood-brain barrier with ultrasound, medical professionals may be able to obtain vital information straight from the brain, enhancing diagnostic methods such as ultrasound-enhanced biopsies.
