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Wednesday, July 21, 2010

Dissolvable microneedles

Vaccinating by injection offers a dangerous temptation to drug users in the form of leftover needles, or ‘sharps’. Scientists from Emory University and the Georgia Institute of Technology may have solved this problem by inventing dissolving microneedle patches. The technique was successfully tested with influenza vaccine in mice.
To make the vaccines, freeze-dried influenza vaccine was mixed with a biocompatible polymer and then solidified into microneedles by using ultraviolet light. The tiny needles are each only 650 microns long and arranged in arrays of 100.

A dissolving microneedle patch compared to a US nickel.
Credit: Credit: Sean Sullivan, Georgia Tech

When placed on the skin, the microneedles penetrate only the outer layers of the skin where they promptly dissolve, leaving the vaccine in the skin. This is actually a very effective way to administer vaccines. In tests on mice, the new micro array performed as well or better than injected vaccines.
More studies must be done before this new vaccination method is accepted for public use. If the new technique does pass safety and efficacy tests, it could prove to be an excellent alternative. The scientists involved envision letting people pick up their vaccine patches at a pharmacy and administering them by themselves at home. Because the vaccine is used in dry form, longterm storage would be possible. And of course, there would be a complete lack of all ‘sharps’.
This microscope image shows dissolving microneedles encapsulating a pink dye used to simulate how a vaccine would be incorporated into the needles.
Credit: Credit: Sean Sullivan, Georgia Tech