Tag Archives: microneedle patch

Microneedle patch from Sweden

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Strictly speaking this isn’t a ‘nano’ story but this work from Sweden provides a complement and contrast to the Australian nanopatch I mentioned in a post earlier today (Dec. 16, 2016). From a Dec. 12, 2016 news item on Nanowerk,

It’s only a matter of time before drugs are administered via patches with painless microneedles instead of unpleasant injections. But designers need to balance the need for flexible, comfortable-to-wear material with effective microneedle penetration of the skin. Swedish researchers say they may have cracked the problem.

In the recent volume of PLOS ONE (“Flexible and Stretchable Microneedle Patches with Integrated Rigid Stainless Steel Microneedles for Transdermal Biointerfacing”), a research team from KTH Royal Institute of Technology in Stockholm reports a successful test of its microneedle patch, which combines stainless steel needles embedded in a soft polymer base – the first such combination believed to be scientifically studied. The soft material makes it comfortable to wear, while the stiff needles ensure reliable skin penetration.

A Dec. 12, 2016 KTH Royal Institute of Technology press release, which originated the news item, describes exactly the limitation that the scientists are trying to surmount,

Unlike epidermal patches, microneedles penetrate the upper layer of the skin, just enough to avoid touching the nerves. This enables delivery of drugs, extraction of physiological signals for fitness monitoring devices, extracting body fluids for real-time monitoring of glucose, pH level and other diagnostic markers, as well as skin treatments in cosmetics and bioelectric treatments.

Frank Niklaus, professor of micro and nanofabrication at KTH, says that practically all microneedle arrays being tested today are “monoliths”, that is, the needles and their supporting base are made of the same – often hard and stiff – material. While that allows the microneedles to penetrate the skin, they are uncomfortable to wear. On the other hand, if the whole array is made from softer materials, they may fit more comfortably, but soft needles are less reliable for penetrating the skin.

“To the best of our knowledge, flexible and stretchable patches with arrays of sharp and stiff microneedles have not been demonstrated to date,” he says.

They actually tested two variations of their concept, one which was stretchable and slightly more flexible than the other. The more flexible patch, which has a base of molded thiol-ene-epoxy-based thermoset film, conformed well to deformations of the skin surface and each of the 50 needles penetrated the skin during a 30 minute test.

A successful microneedle product could have major implications for health care delivery. “The chronically ill would not have to take daily injections,” says co-author Niclas Roxhed, who is research leader at the Department of Micro and Nano Systems at KTH.

In addition to addressing people’s reluctance to take painful shots, microneedles also offer a hygiene benefit. The World Health Organization estimates that about 1.3 million people die worldwide each year due to improper handling of needles.

“Since the patch does not enter the bloodstream, there is less risk of spreading infections,” Roxhed says.

Here’s a link to and a citation for the paper,

Flexible and Stretchable Microneedle Patches with Integrated Rigid Stainless Steel Microneedles for Transdermal Biointerfacing by Mina Rajabi, Niclas Roxhed, Reza Zandi Shafagh, Tommy Haraldson,  Andreas Christin Fischer, Wouter van der Wijngaart, Göran Stemme, Frank Niklaus. PLOS [Public Library of Science] http://dx.doi.org/10.1371/journal.pone.0166330 Published: December 9, 2016

This paper is open access.

Micro needle patches project gets Grand Challenges Explorations grant

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The project being funded with a Grand Challenges Explorations grant (from the Bill & Melinda Gates Foundation) reminds me a lot of the nanopatch that Mark Kendall and his team have been developing in Australia (a project last mentioned in my Aug. 3, 2011 posting). This new initiative comes from the Georgia Institute of Technology and is aimed at the eradication of polio. From the Nov. 7, 2011 news item on Nanowerk,

The Georgia Institute of Technology will receive funding through Grand Challenges Explorations, an initiative created by the Bill & Melinda Gates Foundation that enables researchers worldwide to test unorthodox ideas that address persistent health and development challenges. Mark Prausnitz, Regents’ professor in Georgia Tech’s School of Chemical and Biomolecular Engineering, will pursue an innovative global health research project focused on using microneedle patches for the low-cost administration of polio vaccine through the skin in collaboration with researchers Steve Oberste and Mark Pallansch of the US Centers for Disease Control and Prevention (CDC).

…

The goal of the Georgia Tech/CDC project is to demonstrate the scientific and economic feasibility for using microneedle patches in vaccination programs aimed at eradicating the polio virus. Current vaccination programs use an oral polio vaccine that contains a modified live virus. This vaccine is inexpensive and can be administered in door-to-door immunization campaigns, but in rare cases the vaccine can cause polio. There is an alternative injected vaccine that uses killed virus, which carries no risk of polio transmission, but is considerably more expensive than the oral vaccine, requires refrigeration for storage and must be administered by trained personnel. To eradicate polio from the world, health officials will have to discontinue use of the oral vaccine with its live virus, replacing it with the more expensive and logistically-complicated injected vaccine.

Prausnitz and his CDC collaborators believe the use of microneedle patches could reduce the cost and simplify administration of the injected vaccine.

Iwonder if this team working at the microscale rather than the nanoscale, as Kendall’s team does, is finding some of the same benefits, from my August 3, 2011 posting,

Early stage testing in animals so far has shown a Nanopatch-delivered flu vaccine is effective with only 1/150th of the dose compared to a syringe and the adjuvants currently required to boost the immunogenicity of vaccines may not be needed. [emphases mine]

I find the notion that only 1/150th of a standard syringe dosage can be effective quite extraordinary. I wonder if this will hold true in human clinical trials.

If they get similar efficiencies at the microscale as they do at the nanoscale, the expense associated with vaccines using killed viruses should plummet dramatically. I do have one thought, do we have to eradicate the polio virus in a ‘search and destroy mission’? Couldn’t we learn to live with them peacefully while discouraging their noxious effects on our own biology?