Painful Shots Could be a Thing of the Past
By Sony Salzman
Boston University News Service
BOSTON — Nothing can inspire more fear in a small child than the thought of going to the doctor’s office for a shot, yet with recent advancements in skin-contact drug delivery a visit to the doctor’s office could soon be as quick and painless as putting on a band-aid.
Chemical engineers at the Blankschtein research group at MIT have discovered a new way to deliver drugs from the surface of the skin into the bloodstream without the use of needles. The secret to this trick is applying two ultrasound frequencies to temporarily “break up” the surface of the skin.
According to Doctor Mark Grinstaff of Boston University’s Center for Nanobiotechnology, this research represents “improvements over the current method in the way in which the ultrasound is being applied.”
The first of the two frequencies causes small bubbles under the skin to multiply. The second frequency causes these bubbles to become unstable and implode. When the bubbles implode, they collapse inward, causes the drug on top of the skin to rush into the vacuum.
“When those bubbles explode, a micro-jet is formed and that micro-jet hits the skin like a hammer hitting a wall,” said Daniel Blankschtein, who directed the MIT research. “This disorganizes the skin and makes it more permeable. In a brick wall the cracks stay forever, but in the skin, because it’s a living medium, the cracks close.”
In this study, researchers used the ultrasound effect to deliver lidocaine, a local anesthesia, through an in-vitro pig skin, which has very similar properties to human skin. According to Carl Schoelhammer, who co-authored the paper, this procedure does not penetrate to the skin’s nerve endings and should be painless.
Blankschtein and his colleagues see multiple applications for this technology. The most immediate of which is for vaccinations and other drug deliveries, but Blankschtein says it could be applied as a non-invasive way to extract blood for blood analysis. He is hopeful that one day this method will be used by diabetics to test insulin levels painlessly.
“It liberates you from medical personnel,” he said. “Say that you have people living in remote places; these individuals may be able to do self-administration of vaccines and other drugs. It has important implications for compliance.”
So far, this technology has been used to successfully deliver lidocaine, a local anesthesia, but only in non-living tissue. Blankschtein is careful to note that exhaustive clinical trial testing needs to take place before the process can be safely regimented for widespread use. However, the dual frequency ultrasound method represents and important step towards converting this technology into clinical practice.