Foundations and Frontiers of Bioengineering

Attendees of the 11th annual Warren Alpert Foundation Prize Symposium were given a taste of the future as bioengineering luminaries from Boston and beyond discussed everything from the possibility of lab-grown transplantable livers to self-folding DNA origami.

Two pioneers of bioengineering, surgeon and chemist Alain Carpentier and chemical engineer Robert Langer, the recipients of the 2011 Warren Alpert Foundation Prize, opened the Oct. 6 Symposium at Harvard Medical School’s Joseph B. Martin Conference Center.

Carpentier, head of the Department of Cardiovascular Surgery at the Hôpital Européen Georges-Pompidou in Paris, developed a bioprosthetic heart valve that currently benefits more than 100,000 patients each year. Langer, David H. Koch Institute Professor at the Massachusetts Institute of Technology and senior lecturer on surgery at HMS, has more than 800 granted or pending patents for his work on biopolymers for drug delivery, tissue engineering and other discoveries targeted at improving health. A capacity crowd gathered to honor their achievements.

Carpentier described developing the heart valve as a solution to what he called “the drama of the surgeon.” In order to prevent the body’s natural defenses from causing potentially deadly clots during surgery, doctors use blood thinners. But too much blood thinner causes potentially deadly hemorrhages. The materials in the valve, including pig collagen, are selected and chemically treated to minimize clotting (and immune rejection), in processes that Carpentier and his team have continued to perfect over the last three decades, working in his hospital near the Eiffel Tower.

When discussing the current state of the bioengineering world and the increasing drive toward miniaturization, Carpentier cited the legendary father of nanotechnology and MIT physicist Richard Feynman’s 1959 speech to the American Physical Society in which he called for the development of a “surgeon small enough to swallow.”

“Feynman would be glad to know we have followed his advice,” Carpentier said.

An almost-literal incarnation of the tiny surgeon, Langer’s developments include biopolymer microspheres designed to deliver drugs in controlled, sustained dosages. He recalled that in the early days of bioengineering, physicians would use materials that approximated the function they were trying to replicate.

Unfortunately, in many cases, the similarity was superficial. An early artificial heart was made of polyether urethane, a strong, stretchy lady’s girdle material, which was then found to cause clotting—a serious drawback in a blood pump.

Langer brought a material scientist’s perspective to the creation of medical devices, using substances that are not only safe but functional: his group has created knots that tie themselves when they reach body temperature, and drug delivery polymers that erode at specific rates to control dosage.

Following Carpentier and Langer, three researchers reported on how they are carrying this and similar work forward.

“This symposium gives us a look back at the approaches of two of the giants of this field over the last thirty or forty years, and a glimpse into the future of what is possible,” said Dean of the Faculty of Medicine Jeffrey S. Flier.

David Mooney, Robert P. Pinkas Family Professor of Bioengineering and core faculty member at the Wyss Institute for Biologically Inspired Engineering at Harvard University, presented a potential cancer vaccination process that combines nanotechnology with gene therapy. It isn’t just like swallowing a surgeon, it’s like swallowing a whole cell therapy lab that activates the body’s own immune system without the expense and complications of current techniques.

Sangeeta Bhatia, John J. and Dorothy Wilson Professor of Health Sciences and Technology & Electrical Engineering and Computer Science at MIT, discussed the challenges of moving tissue engineering from relatively simple skin and muscle to more complex functional tissues. Her group is laying the groundwork for engineering a working, living liver using techniques borrowed from microprocessor manufacturing.

William Shih discussed his work with the self-assembling, nanoscale forms known as DNA origami. Shih is an HMS associate professor of biological chemistry and molecular pharmacology at the Dana-Farber Cancer Institute, as well as a core faculty member at the Wyss. His team is creating ever more complicated forms that self-assemble from a simple mix of chemicals. These cubes, rings and other more baroque figures can already probe cell behavior and analyze single-molecules, and may soon deliver drugs to targeted sites.

Using what Shih called a “hacker mentality,” these projects are working beyond the current boundaries of known science. These teams don’t always know precisely how or why these technologies work, but they are learning as they go and building tools for more learning and for the clinic along the way.