Skin is a complex organ that varies a lot from person to person. Its strength, elasticity, and permeability all impact how substances are transported across the skin and through its surface, making the development of novel vaccination approaches a challenge. To move biomedical fields toward minimally invasive, transdermal drug delivery, Magalí Mercuri and David Fernandez Rivas reviewed computational and experimental methods for studying the skin’s permeability.
“One would think that since we all have skin, by now, we would have unveiled all its secrets, but the opposite is true,” said Fernandez Rivas.
Common imaging techniques, like ultrasound and MRI, each have their own individual benefits for studying skin permeation processes. A shared shortcoming, however, is their limited spatial resolution. Because understanding the skin’s mechanical properties is key to unlocking unique, painless injection procedures, computational models are an important tool in biophysics.
With realistic, accurate descriptions of the tissue, next-generation transdermal drug delivery methods can become more commonplace. These include needle-free injection devices, such as microjets, where a tiny liquid jet or a series of them penetrates the outer layer of the skin, and tattooing, which can finely tune the delivered drug dosage into an area that generally promotes a higher immune response. These types of advances will help personalize treatment and reduce wounding.
Mercuri and Fernandez Rivas emphasize the technological challenges that must be overcome to achieve these niche, skin-based treatments. This will require a large amount of interdisciplinary collaboration to image, model, and track the behavior of drugs through different delivery systems in real time.
“There is plenty to explore under our skin,” Fernandez Rivas said.
Source: “Challenges and opportunities for small volumes delivery into the skin,” by Magalí Mercuri and David Fernandez Rivas, Biomicrofluidics (2021). The article can be accessed at https://doi.org/10.1063/5.0030163.
