Mini-needles 'give painless jabs'

A tiny plate containing up to 400 needles is used and tests have found them to be completely painless. Enlarge Image

Squeamish patients who cannot stand the sight of needles could be offered pain-free injections, thanks to the work of Cardiff scientists.

The new micro-needles are long enough to penetrate the skin but not to reach pain receptors.

They were designed to introduce a DNA vaccination directly into skin cells.

They were revealed at the British Pharmaceutical Conference and developed at the Welsh School of Pharmacy at Cardiff University.

'Bed of nails'

The micro-needles, made by the Tyndall National Institute in Ireland, measure up to 300 microns (0.3mm) across, and are barely visible to the naked eye.

A tiny plate containing up to 400 needles is used and tests have found them to be completely painless.

James Birchall, head of the gene delivery research group, said: "Think of the bed of nails effect - the forces are spread over a wide surface area."

Dr Birchall said conventional needles went in too deep for the method of "genetic vaccination" his team was developing.

The micro-needles worked by creating temporary channels in the skin to allow the vaccine to reach "immune-responsive" skin layers, he said.

Cheap to make

They are currently made of silicon, but biodegradable needles that dissolve in the skin are a future possibility.

Dr Birchall said DNA vaccines delivered via a micro-needle could have several advantages over standard vaccines.

The new micro-needles are said to be completely pain-free

"They are likely to be cheaper and easier to make. The micro-needle system might also be developed as a patch for self-application, avoiding the need for a clinician," said Dr Birchall.

"There is also reduced risk of transmission of blood-borne pathogens by inappropriate re-use of needles. These are all particular advantages for the developing world.

"Pain-free vaccination could also be useful for childhood vaccines in developed countries."

The next stage of the research will investigate delivery of vaccines such as hepatitis B and influenza.

The new needles are not likely to be seen in hospitals or surgeries for at least five years.