Several professors explored research at the interface of engineering and biology at a workshop last week aptly symbolized by the walkway between MIT's biology and chemical engineering buildings.
In opening remarks at Materials Day, October 16, Professor Douglas A. Lauffenburger noted that good engineering is supported by the pillars of physics, math and chemistry. "Biology has to take its place alongside these [to develop] the technologies of the future," said Dr. Lauffenburger, the J.R. Mares Professor of Chemical Engineering and co-director of the Division of Bioengineering and Environmental Health (BEH).
"The goal of this workshop is to sensitize the materials [engineering] community to ways in which this pillar can be built," he said.
The evolution of prosthetics, he said, is a good example of how the relationship between biology and engineering is changing. Replacement limbs were originally made of wood, then metals, then plastics. "Now molecular biology has shown that a very sophisticated system of living cells continuously regenerates... bone." As a result, "today we don't try to replace the bone, but rather try to regenerate it from its biological components." The challenge: "How do you engineer cells to get a living system that's not an inanimate mimic?"
Among the day's speakers was Professor Roger D. Kamm of the Department of Mechanical Engineering and BEH. He described his work to understand how cells respond to mechanical stress. He explained that such stress "has a variety of extremely important implications." For example, it is key to diseases like arthritis and atherosclerosis. Mechanical stress can, however, be beneficial, "and used to our advantage to elicit a desired cellular response."
To study the mechanical stress on cells, Professor Kamm has applied several tools of materials science, from standard stress-strain tests to atomic force microscopy. He and colleagues have also developed simulations looking at the stress on cells as they squeeze through capillaries in the body.
Saying her research is "inspired by nature," Barbara Imperiali, the Ellen Swallow Richards Professor of Chemistry, uses synthetic fluorescent polypeptide structures as sensors to detect metal ions in a variety of media.
The design of these sensors involves a metal ion recognition site and a reporting site. Solid phase peptide synthesis can be used to synthesize and screen libraries of potential sensors for optimal properties. These new sensors may have environmental and physiological applications. For example, with specifically designed peptide architecture, Professor Imperiali can zoom in on specific metal ions in blood serum. This could lead to a rapid, inexpensive, noninvasive method of screening for zinc and other metal ions in blood.
Professor Imperiali's group has now come up with strategies for sensing biologically important metals such as divalent copper, trivalent iron and divalent nickel. Trivalent iron in the bloodstream may indicate certain medical problems; different levels of copper could help diagnose disease.
Other MIT speakers at Materials Day were Professor Paul T. Matsudaira, Department of Biology and BEH; Professor Anne M. Mayes, Department of Materials Science and Engineering; and Professor Linda G. Griffith, Department of Chemical Engineering.
Materials Day was sponsored by the Materials Processing Center. It was co-chaired by Professor Lauffenburger and Professor Robert E. Cohen, the St. Laurent Professor of Chemical Engineering. "It was a lot of fun to select [speakers and projects] from across campus that bear on this interface," Professor Lauffenburger said.
A version of this article appeared in MIT Tech Talk on October 25, 2000.