An array of microneedles like this could be coated with medicine and act as a painless drug delivery system for flu vaccines, diseases of the eye and more.

Good news for those who are squeamish around needles: Researchers have designed a Band-Aid-like painless patch that could replace the sting of shots.

These patches, lined with tiny "microneedles," could make treatment of diabetes and a wide range of other diseases safer, more effective and less painful, the scientists who developed them say. The patch could ultimately replace even flu shots.

"It's our goal to get rid of the need for hypodermic needles in many cases and replace them with a patch that can be painlessly and simply applied by a patient," said one of the developers, Mark Prausnitz of Georgia Tech. "If you can move to something that's as easy to apply as a Band-Aid, you've now opened the door for people to self-administer their medicine without special training."

In the past, researchers have also developed other technologies aimed at reducing the painful prick of needles, including a tattoo of sorts that monitors blood sugar levels of diabetics, a vein finder to reduce the number of times the nurse has to stick your arm, and water pistol-like jet injectors that can be used the same as needles.

Each needle in the new patch is only a few hundred microns long, about the width of a few strands of human hair.

Advances in the electronics industry in microfabricating very small objects like transistors enabled the development of microneedles, the researchers said.

"We've built off those technological advances to address a need in medicine," Prausnitz said. "We're trying to bring the two worlds together."

Prausnitz and his colleagues suggest the patches could replace the yearly trip to the doctor for a flu shot, too.

"Although it would probably first be used in a clinical setting, our vision is to have a self-administered flu vaccine patch. So instead of making an appointment with your doctor to get your flu shot, you can stop by the pharmacy or even get a patch in the mail and self-apply," Prausnitz said. "We think that could very much increase the vaccine coverage since it would be easier for people to be vaccinated."

Prausnitz and his colleagues tested the patch and traditional needle injection methods of flu shots in mice and measured the resulting antibody levels. They found that the levels were the same for both methods and that the microneedle approach resulted in better immune response by other measures.

The microneedles could also be used to deliver drugs to the eye, potentially creating improved treatment for macular degeneration, the leading cause of blindness in the United States.

The patch design was presented today at the 238th National Meeting of the American Chemical Society in Washington, D.C.