NJIT mathematician receives NSF grant to study interaction of skin and surfactants

NJIT Associate Professor Yuan-Nan Young has been awarded a three-year, $212,000 National Science Foundation grant to mathematically model how surfactants interact with the skin's lipid bi-layer. A surfactant, also known as a wetting or surface-acting agent, breaks the surface tension of a liquid to create more contact with another substance. Soap is the best-known surfactant.

"The interaction between proteins and the cellular membrane is crucial to proper cellular function and signaling," said Young. "Researchers have tried understanding the fundamental biophysics underlying such interaction for drug delivery to cure diseases. The more we know about this complicated interaction between proteins and cellular membranes, the better we can control such interaction to improve our medicinal technology."

The lipid bi-layer is the main structural component of the elastic biological cell membranes that consist of different lipid species, and contain many kinds of proteins and many other molecules such as cholesterols and surfactants.

Also working with Young are University of Michigan Assistant Professor Shravan Veerapaneni, who is studying state-of-the-art numerical simulation, and Howard Stone, the Donald R. Dixon '69 and Elizabeth W. Dixon Professor in Mechanical and Aerospace Engineering at Princeton University, who will be experimenting with micro-fluids. The trio will aim to elucidate the mathematics and biophysics governing the interaction between proteins, surfactants, and lipid bi-layer membranes.

Young is a member of the NJIT Department of Mathematical Sciences in the College of Science and Liberal Arts.

It is known that lipid composition may set limits to the possible shapes and deformations, while the actual shape of the cellular membrane depends on both the force (from the cytoskeleton, for example) and membrane-deforming proteins.

Progress has been made to uncover and decipher the mechanisms by which proteins can sense and/or induce membrane curvature. However, recent experiments have shown that interaction between lipid membranes and amphipathic molecules, such as surfactant and amphipathic peptides, also leads to changes in total membrane area, curvature and rigidity.

"What interests me is that until now, there has been no mathematical modeling of these effects to learn more about the asymmetry in the lipid bi-layer due to surfactants and proteins," said Young. "There's also been no work on how cells may utilize these mechanisms to perform diverse biological functions."

This project aims to establish mathematical understanding of the roles of surfactants and proteins in causing the asymmetries in lipid double leaflets and their subsequent shape and dynamics. Results will shed light on the complex interactions between proteins and membranes, which are essential to cellular functions and signaling.

Provided by New Jersey Institute of Technology