How electric pulses and heat safely open microscopic pores in the human skin

What is it about?

This paper examines how exposing the skin to a series of electrical pulses—a technique known as electroporation—temporarily opens microscopic pores in the stratum corneum, which is the outermost layer of the skin. Ordinarily, this layer acts as a tough barrier composed of dead cells and organized lipids (fats) that prevents large molecules, such as certain medications, from passing through. To understand the exact mechanics of how these pores develop, we created a transient mathematical model to simulate human skin undergoing in vivo electroporation. We discovered that the electrical current concentrates in specific, less resistive spots, generating highly localized heat. This rapid heating essentially fluidizes or "melts" the organized lipid structures holding the skin barrier together, which decreases electrical resistance and allows the tiny pores to expand radially outward.

Featured Image

Photo by Benoit Roy on Unsplash

Photo by Benoit Roy on Unsplash

Why is it important?

Transdermal drug delivery—delivering medication directly through the skin—is highly desirable because it is painless and avoids the digestive system, but the skin's robust natural barrier makes it historically difficult. Our work is uniquely timely because it connects the thermal energy (Joule heating) of electroporation directly with the physical melting of skin lipids, providing a detailed theoretical map of how these pores actually grow over time. By mathematically modeling how localized heating spreads during this process, we can help optimize the electrical pulse patterns used in real-world medical devices. For example, our findings demonstrate that using multiple short electrical pulses with cooling times in between prevents viable underlying tissue from overheating, which is a crucial insight for ensuring patient safety while maintaining effective pore growth.

Perspectives