Investigating the hole story of making pores in cell membranes

Promising gene editing technologies like CRISPR can't get into cells on their own. State-of-the-art methods for transport and delivery are expensive. To make gene therapies available to more patients, we need more consistent and controllable ways to make holes in cell membranes.

At Carnegie Mellon University, Derin Sevenler is developing strategies to more effectively load molecules into cells. Sevenler, assistant professor of chemical engineering, has been awarded a Maximizing Investigators' Research Award (MIRA) from the National Institutes of Health (NIH). The award provides $1.9 million over five years for Sevenler's research into pore formation and repair in cell membranes.

The outer membrane of a cell is thin and tough. It's flexible but not very stretchy. Picture a plastic grocery bag filled with gelatin.

Distinct patches of proteins, lipids, carbohydrates, cholesterol, and other components can diffuse along the membrane. "The cell membrane is a complex, heterogeneous, dynamic, living material that's constantly being remodeled," says Sevenler.

His lab is developing a quantitative understanding of what happens in cell membranes when they are pulled and stretched at very short time scales. Sevenler uses the forces that arise in fast-moving viscoelastic fluids to manipulate cells.

Across medicine and biotechnology, there are many studies showing what can be achieved with particular methods for loading molecules into cells. Yet there is a lack of research into what is happening to the cell membrane as different forces are applied. "At a mechanistic level, we don't understand exactly what is going on across all these methods," says Sevenler.

Opening up the membrane to load molecules into the cell is similar to surgery. "A lot of work has been done to show that cells will repair their membrane after a wound is created. Relatively little work has been done trying to understand how to support the cell repair processes and make cell healing as efficient and gentle as possible," says Sevenler. Surgeons don't just open up their patients. They also help their patients recover. Sevenler's work can be used to create similar standards for cell "surgery."

According to the NIH, the goal of MIRA is to provide highly talented and promising investigators with greater stability and flexibility, thereby enhancing scientific productivity and the chances for important breakthroughs.

Sevenler's methods are efficient, safe, and gentle on cells. They are also scalable for clinical and manufacturing applications.

"Genetic modification is challenging to do in a very consistent and safe way," says Sevenler. "The methods that are available right now satisfy the industry needs, but the resulting products are too expensive for many patients who need them."

Motivated by a vision for more accessible gene therapies, Sevenler doesn't stop when he builds an instrument that works. He's also building our understanding of why it works.

This research is supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R35GM159950. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

For media inquiries, please contact Lauren Smith at lsmith2@andrew.cmu.edu.