Researchers have developed a method to quantify the hydraulic permeability—the ability of water to move in all directions through tissue—in the dermis.
The findings were published in the journal PNAS Nexus (Aug. 2023; 2(8):240).
Researchers used a novel approach called atomic force microscopy-based nanoindentation to study 14 ex-vivo human skin samples with a polystyrene nano-probe. This approach enabled the authors to quantify the biophysical characteristics of individual layers of ex vivo human skin.
“We have discovered that our new methods are highly sensitive to the mechanical properties of individual skin layers, as well as their hydration properties,” the authors write, noting the technique can assess how the skin layers respond to compressive and shear deformation.
“The poroelasticity model used helps to quantify the hydraulic permeability of the skin layers, providing an innovative method to evaluate and interpret the impact of hydrating compositions on water mobility of these different skin layers.”
Researchers found that hydraulic permeability is highest in the dermis. When the skin is depressed, water moves away through the tissue matrix and cells of the dermis, and flows backwards when the mechanical pressure is released. They found the stratum corneum had the least permeability, suggesting that this layer is an important barrier for water loss.
The authors suggest their method can be used to assess the effect of lotions, creams, and other skin additives designed to increase the plumpness or moisturizing level of the skin.