Image caption The patch is covered in microscopic needles

US scientists have designed a super-grip plaster covered with microscopic needles to heal surgical wounds.

The "bed-of-needles" patch, inspired by a parasitic worm that lives in the guts of fish and clings on using its cactus-like spikes, fixes skin grafts firmly in place without the need for staples.

Its creators say the patch is three times stronger than the materials currently used for burns patients.

Tests in animals have been a success, Nature Communications journal reports.

The Boston team, based at Brigham and Women's Hospital, says the four-sq-cm (0.6-sq-in) patch could also deliver therapeutic drugs via its tiny needles.

The unique design allows the needles to stick to soft tissues with minimal damage to the tissues Lead researcher Dr Jeffrey Karp

Wet wounds

Image caption The parasite has spines that swell when wet

Most self-adhesive bandages stick poorly to wet skin. Staples and stitches can help anchor dressings and skin grafts but inevitably cause some trauma to the tissue.

To get round this problem, Dr Jeffrey Karp and his team looked to nature in the form of a parasitic worm called Pomphorhynchus laevis.

The parasite anchors itself to the slippery surface of the host intestine using micro-needle tips that pierce the surface and then, once wet, swell to lock tight.

This means the needles cause little damage as they go in, yet achieve maximum grip.

Dr Karp's patch mimics this action using minute needles made of plastic with tips that are rigid when dry but swell once they have pierced wet tissue.

Dr Karp said: "The unique design allows the needles to stick to soft tissues with minimal damage to the tissues.

"Moreover, when it comes time to remove the adhesive, compared to staples, there is less trauma inflicted to the tissues, blood and nerves, as well as a reduced risk of infection."