Ultrasound Waves For Transdermal Drug Delivery

An anonymous reader writes with news of research from MIT, where engineers have found a better way to use ultrasound waves to boost the permeability of skin for the delivery of drugs. "Ultrasound — sound waves with frequencies greater than the upper limit of human hearing — can increase skin permeability by lightly wearing away the top layer of the skin, an effect that is transient and pain-free. ... When ultrasound waves travel through a fluid, they create tiny bubbles that move chaotically. Once the bubbles reach a certain size, they become unstable and implode. Surrounding fluid rushes into the empty space, generating high-speed 'microjets' of fluid that create microscopic abrasions on the skin. In this case, the fluid could be water or a liquid containing the drug to be delivered. In recent years, researchers working to enhance transdermal drug delivery have focused on low-frequency ultrasound, because the high-frequency waves don’t have enough energy to make the bubbles pop. However, those systems usually produce abrasions in scattered, random spots across the treated area. In the new study (abstract), the MIT team found that combining high and low frequencies offers better results. The high-frequency ultrasound waves generate additional bubbles, which are popped by the low-frequency waves."

Question for the med community

[AnotherAnonymousUser]

I realize Google is my friend in this, but I'd love to hear from insider perspective what sort of advances are actually *in use* in clinics and hospitals these days. About 10-15 years ago I used to read in Pop Sci about the innovations in needle technology - serrating the edge like a mosquito, using thinner needles, new kinds of shots, and using these painless, efficient methods of delivering vaccines and medicine. What of those actually panned out? It's been about 10 years since I've received a vaccination; did any of those technologies we read about 10 years ago make it into the field?

This is good

[Anonymous Coward]

I read a few weeks ago that a group trying to kill cancer mated an ultrasound machine with an MRI. They targeted the cancer with the MRI, and blasted it (in 3 dimensions) with the ultrasound. Ultrasound makes cancer tumors 'fragile'. They are far more prone and are profoundly more affected by chemotherapy than they would be otherwise. What do I mean by that? Normally after 6 weeks of chemotherapy, a tumor might shrink by 30%. After the MRI/ultrasound and a single dose of chemotherapy, the tumor might shrink by 50% (in rough and general terms, they did multiple tests on multiple patients and these are generated averages). Its like 'it just isn't for the epidermis, but can be used to make the cancer tumor 'skin' more prone and able to absorb the chemo coctail more easily, making the treatment more effective, leaving less chemo cocktail in the rest of the body, meaning the tumor suffers the worst, and surrounding tissue is affected less.

Re:Already got one.

[BoRegardless]

What I am interested in is whether the ultrasound modifies the chemicals being transported -- injected???

Ultrasonic bubbles can create implosions that raise temperatures into the range of thousands of degrees farenheit.

Ultrasonics are routinely used to bond plastics as a result of the temperatures induced.

The question comes down to whether you destroy or modify the molecules you want to deliver...however slightly. Needles don't do that.

Re:Question for the med community

[TheSwift]

I'm a pre-med student and I work for physicians in an emergency department. I've seen several pretty nifty innovations for administering IV's. In pediatric hospitals, they often use air-pressure needle-free methods of starting IV's and administering medications. To be honest, I'm not sure how they work, but they do exist and instead of having a metallic needle in your arm, it is tough, but malleable plastic. They aren't generally used mainstream in most hospitals yet, especially not in the ER. My guess is that they are more expensive and it may be more difficult to start IV access to an adult vein using needle-free technology. Some benefits though, are a reduction in introducing bacteria to a bloodstream (no potentially contaminated needles) reducing the "scare factor" from having a needle shoved in your arm. One of my close friends is a cancer survivor and he had the technology used on him many times and he said it hurts a helluva lot less than needles. http://www.icumed.com/products/infusion-therapy/needlefree-vascular-access-devices.aspx [icumed.com] BTW, thinning needles isn't always helpful, especially if you want to administer drugs quickly (critical care situations).