A pain-free delivery method for DNA material to be placed in the skin holds great potential for developing countries.
Researchers have developed a patch that uses barely visible needles to inject a new DNA vaccine under the skin, much like tattoo needles - only painlessly.
DNA vaccines work by inserting DNA holding the code of a virus or bacteria protein directly into the body's cells. The body then detects this foreign protein and creates an immune response.
However, to date, DNA vaccines have failed to generate immune responses in humans in the same way as conventional vaccines, and they have not yet been shown to be safe, reproducible and pain-free.
But new research from Massachusetts Institute of Technology (MIT), published in Nature Materials, has led to a pain-free DNA vaccine skin patch that has been proven to work on macaque monkeys. This patch proved over 100 times more effective than a normal needle.
"The hope is that this technology would provide a lower-cost means to deliver vaccines, which might even be self-administered in the future," said one of the researchers, Darrell Irvine, from the Department of Materials Science and Engineering at MIT.
"As it is based on DNA, it may also provide a universal platform for developing vaccines against many different diseases, by simply changing what the DNA encodes," Irvine said.
The microneedles, which don't penetrate to the nerve endings of the dermis and which are therefore painless, quickly dissolve, leaving behind a film that releases the vaccine for weeks.
"Like tattoo ink that is deposited permanently in the skin, these skin patches deposit a very thin layer of polymer film containing DNA into the skin. Unlike a tattoo, these 'DNA tattoos' dissolve over a few weeks to carry out the vaccination," Irvine said.
This delivery method has huge potential for the developing world, especially as the vaccine patches don't need to be refrigerated, and it could one day be used to vaccinate people against HIV and perhaps even train the immune system to fight cancers.Do you have an idea for a story?
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