Scientists develop skin patch that painlessly delivers drugs into the body

An affordable microneedle skin patch that delivers a controlled dose of medication directly into the body, eliminating the need for injections or oral medication, has been developed by a team led by scientists from the University of Bath .

We hope that the fixes described in the log Advances in biomaterialswill be ready for use within five to ten years.

What makes microneedle patches unique is that they are made from a hydrogel (a gel-like substance in which water forms the liquid component), with the active ingredient encapsulated at inside the microneedle structure of the hydrogel rather than in a separate reservoir.

They are also more affordable than other commercially available microneedle patches because they are produced from 3D printed molds. Molds produced in this way are easy to customize, reducing costs.

Painless delivery

The patch is smaller than a pound coin. Barely visible microneedles painlessly pierce the first layers of the skin. Contact with liquid below the skin barrier causes the “hydrophilic” (water-loving) needles to swell, resulting in a specific dose of the medication being delivered into the body.

In experiments carried out in Bath, when swelling occurred, the patches delivered doses of antibiotics which caused a strong response against two bacteria known to cause serious infections, Escherichia coli (E. coli) and Staphylococcus aureus.

The patch also works in reverse, extracting small amounts of fluid from under the skin for medical analysis. This can be useful, for example, for monitoring levels of lactate (a component of lactic acid) and other chemicals in infected patients.

Obvious advantages

Bath chemical engineer Dr Hannah Leese, who continues to refine the skin patch design with her fellow PhD engineers. Student Joseph Turner and Professor Pedro Estrela, together with biologist Dr Maisem Laabei, say microneedle-based skin patches are an ideal system for drug delivery and have clear advantages over conventional approaches. traditional administration.

She said: “The injections are invasive and expensive, and they are not suitable for everyone. Many people are needle phobic and are understandably reluctant to receive medication by injection, even when treatment is truly necessary. Others are poorly suited to injections, for example. , elderly patients with thin skin.

“In addition, the use of needles can sometimes introduce pathogens, such as bacteria, that can cause infections, especially in people with low immunity.”

She added that people generally have fewer objections to taking oral medications, but that oral medications also have disadvantages.

She said: “You may experience gastrointestinal side effects; there is a delay between taking the medicine and it arriving where it is needed in the body; doses need to be higher because much of the formulation is broken down in the intestine. and if the patient is taking antibiotics, this can also contribute to antimicrobial resistance.

Towards clinical trials

“Our next step is to continue to refine the microneedling platform and conduct animal studies before moving into human clinical trials,” said Dr. Leese, adding, “I hope that these patches will be ready for use by patients within five to ten years. years.”

Dr. Leese anticipates that the patches will be able to deliver both medications that circulate throughout the body and medications that need to remain more localized, such as if there is an infection in a discrete area of ​​the skin. The patches can also help administer vaccines and monitor hormone levels.

“We can also see that these patches can play a role in areas of health and wellness,” she said. “I can imagine the day when people place microneedles under their smartwatches to detect fluctuations in the stress hormone cortisol.”