Figure 1 - The underside of the patch has rows of tiny, cone-shaped needles.

When giving thanks to Mother Nature for the bounty that she provides, a parasitic worm may not be on your top 10 list. But a Brigham and Women’s Hospital (BWH) research team has seen the beauty in a spiny-headed worm, the Pomphorhynchus laevis, and used this creature as inspiration for designing an adhesive patch that safely and strongly secures human skin grafts.

This unique worm establishes long-term residency in the intestines of fish by plunging head-first into the host’s intestinal wall and then swelling its head to create a secure hold in the intestinal tissue. Impressed by the strength and simplicity of this technique, a research team led by Jeffrey Karp, PhD, Division of Biomedical Engineering, Department of Medicine, developed a micro-needle patch that mimics the worm’s anchoring mechanism.

On the underside of the patch are rows of tiny, cone-shaped needles (Figure 1). Each needle features a solid core that retains its form whether wet or dry, and a tip that is sharp and rigid when dry, but swells when exposed to water (Figure 2). The fine micro-needles easily penetrate tissue and then maintain a strong hold after the tips are swollen through hydration.

“The adhesion strength of the micro-needle tips are more than three times stronger than conventional surgical staples used for skin graft fixation,” says BWH research fellow and study author Seung Yun Yang, PhD.

And just as easily as the patch can be strongly secured, the swollen tips can be deformed and easily removed through the holes created by the needles. This easy-in, easy-out technology softens the impact on a patient’s tissue.

Figure 2 - Each needle features a tip that swells when exposed to water.

“The unique design allows the needles to stick to soft tissues with minimal damage to the tissues,” says Dr. Karp. “Moreover, when it comes time to remove the adhesive, compared to staples, there is less trauma inflicted to the tissue, blood, and nerves, as well as a reduced risk of infection.”

Along with its potential to provide a safer and stronger hold, researchers suggest that the patch’s design also could enable physicians to deliver therapeutics into damaged tissue.

“I envision that this device will be very effective in treating patients, both by skin graft fixation, but also by delivery of active substances into the surface of the wound,” says study author Bohdan Pomahac, MD, Director, Plastic Surgery Transplantation and Burn Center. “These substances may be for example, antibiotics, growth-promoting compounds, or anti-inflammatory molecules.”

Further details of the study are available in the April 16, 2013 issue of Nature Communications.

– Chris P.

comments (0)