By Mark Dwortzan
From the mechanics of single molecules to cell membranes, Professor Evan Evans (BME) has made fundamental contributions to the field of biomechanics in a career spanning four decades. A pioneering researcher at the intersection of biology, engineering and physics, he has published hundreds of seminal papers and book chapters.
To celebrate Evans’ many achievements in biomechanics and their impact on the field—as well as his 70th birthday—Assistant Professor Matthias Schneider (ME) and the Biomedical Engineering Department convened a daylong biomechanics symposium at the Photonics Center auditorium on Oct. 15. Fifteen speakers, many of them past collaborators and former students, presented highlights of their research and Evans’ influence on its success.
Much of the speakers’—and Evans’—research examines properties of synthetic and natural membranes and biological cell structure, and the role of force in cellular processes. As director of Boston University’s Whitaker Laboratories for Cellular and Subcellular Bioengineering, Evans works to expose the underlying physical mechanisms used by nature in the design of complex biological organisms, and apply insights derived from this research to design nanostructures for a wide range of applications.
Several talks at the symposium showcased emerging applications in the life sciences and medicine inspired by Evans’ ongoing exploration of nature’s engineering.
For example, Herman Gaub, a professor of physics and biophysics at Ludwig-Maximilian University in Munich who collaborated with Evans during one of the BME professor’s sabbatical years, described a “single molecule cut-and-paste” method he’s developed to assemble sets of individual molecules, such as enzymes, in a designated order and geometry. The technology may ultimately be used to design tailor-made living cells with specific biological functions, such as the splitting of oil, or to fabricate nanomachines with desired functions.
“The goal is to build up structures at the nanometer length scale from individual units—be it an enzyme or a nanoparticle,” said Gaub, whose method relies on the precise positioning of the tip of an atomic force microscope. “Synthetic biology offers us a viable approach to build systems, and from building them, understand how they work, and that might be a means of building enzyme networks and understanding them better.”
Wesley Wong, a principal investigator at the Rowland Institute at Harvard University who was advised by Evans as an undergraduate and Ph.D. student, discussed an inexpensive, user-friendly device called a “centrifuge force microscope” (CFP) that he’s developed to measure the behavior of biological molecules subject to mechanical force. Consisting of a miniaturized microscope, a small LED, an empty tube and a camera on a rotating stage, the CFP can perform thousands of single-molecule measurements in parallel. Using the CFP, Wong has studied natural processes, including antigen-antibody interactions, at the molecular level.
Fundamental Biophysics Research
Other speakers shared highlights of more fundamental biophysics research. Sam Safran, professor of physics at the Weizmann Institute of Science in Israel, explored the mechanical adaptation of cells to their environment, and Erich Sackmann, professor of physics and biophysics at Ludwig-Maximilian University in Munich and a pioneer in biophysics, described how cells crawl along a surface.
Several presenters remarked on the profound influence of Evans’ work on their careers. Wolfgang Helfrich, professor emeritus of physics at the Free University Berlin and expert on the physics of fluid membranes, recounted extensive discussions that he and Evans have engaged in since 1975. Adrian Parsegian, a professor of physics at the University of Massachusetts, Amherst, marveled at the lasting impact of Evans’ distinctive wit.
“He proclaims an idea, as if it is obvious, and gets us thinking in a direction we would not have thought,” Parsegian observed. “It seems as though he himself doesn’t recognize his originality. It’s all so clear to him, right from the start.”
Evans earned a Ph.D. in Engineering Science from the University of California, San Diego, joined the faculty at Duke University in 1973 where he rose to be appointed a full professor, served as professor of physics and pathology at the University of British Columbia starting in 1981, and joined the BME Department as a full professor in 1997.