Larry McIntire, Ph.D.

For Larry McIntire, biomedical engineering is where new discoveries get turned into products that help people.

It’s a field that reaches across subjects—biology, chemistry, medicine—and one that often brings scientists nose-to-nose with regulatory agencies like the federal Food and Drug Administration (FDA).

“We have a lot of interest because of devices, therapeutics, and drugs, with things like how the FDA runs and how it runs approval processes for various types of things, which can be quite different depending on whether it’s a device or a cell or a chemical,” said McIntire, the chair emeritus of the Wallace Coulter Department of Biomedical Engineering at Georgia Tech—a joint venture with nearby Emory University in Atlanta. “It’s mostly public policy that controls exactly how that happens.”

The mechanics of those processes are part of what got him interested in how science and government intersect, and part of what got him more involved with AAAS. In addition to his post at Georgia Tech, McIntire is the current chair of the AAAS Section M (Engineering)—one of 24 Sections within the organization that advise the leadership on public issues related to their disciplines.

“I think it’s important that scientists and engineers have a real voice in Washington, where all these decisions are made,” McIntire said.

For Larry McIntire, biomedical engineering is where new discoveries get turned into products that help people.

It’s a field that reaches across subjects—biology, chemistry, medicine—and one that often brings scientists nose-to-nose with regulatory agencies like the federal Food and Drug Administration (FDA).

“We have a lot of interest because of devices, therapeutics, and drugs, with things like how the FDA runs and how it runs approval processes for various types of things, which can be quite different depending on whether it’s a device or a cell or a chemical,” said McIntire, the chair emeritus of the Wallace Coulter Department of Biomedical Engineering at Georgia Tech—a joint venture with nearby Emory University in Atlanta. “It’s mostly public policy that controls exactly how that happens.”

The mechanics of those processes are part of what got him interested in how science and government intersect, and part of what got him more involved with AAAS. In addition to his post at Georgia Tech, McIntire is the current chair of the AAAS Section M (Engineering)—one of 24 Sections within the organization that advise the leadership on public issues related to their disciplines.

“I think it’s important that scientists and engineers have a real voice in Washington, where all these decisions are made,” McIntire said.

Researchers have for the first time demonstrated that mechanical forces can control the depolymerization of actin, a critical protein that provides the major force-bearing structure in the cytoskeletons of cells. The research suggests that forces applied both externally and internally may play a much larger role than previously believed in regulating a range of processes inside cells.

Using atomic force microscopy (AFM) force-clamp experiments, the research found that tensile force regulates the kinetics of actin dissociation by prolonging the lifetimes of bonds at low force range, and by shortening bond lifetimes beyond a force threshold. The research also identified a possible molecular basis for the bonds that form when mechanical forces create new interactions between subunits of actin.

Found in the cytoskeleton of nearly all cells, actin forms dynamic microfilaments that provide structure and sustain forces. A cell’s ability to assemble and disassemble actin allows it to rapidly move or change shape in response to the environment.

The research was reported March 4 in the early online edition of the journal Proceedings of the National Academy of Sciences (PNAS). The work was supported by the National Institutes of Health (NIH).

“For the first time, we have shown that mechanical force can directly regulate how actin is assembled and disassembled,” said Larry McIntire, chair of the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University and corresponding author of the study. “Actin is fundamental to how cells accomplish most of their functions and processes. This research gives us a whole new way of thinking about how a cell can do things like rearrange its cytoskeleton in response to external forces.”