Mending the human machine

With its mirror-like reflection of the grand old houses of Hillhouse Avenue and Trumbull Street, the sweeping glass façade of the Daniel L. Malone Engineering Center is one of the most striking sights in New Haven these days. As the new home for Yale’s Department of Biomedical Engineering (BME), the building’s placement—between the School of Medicine and Science Hill, a bastion of basic biological research at the northern end of the central campus—could not be more apt.

“Biomedical engineering in the future has to be more intertwined with basic biological science, because we’re working deeper in the body, with cells and biological molecules,” says department Chair W. Mark Saltzman, Ph.D., Goizueta Foundation Professor of Chemical and Biomedical Engineering. “On the other side, biomedical engineers need to be much more involved with translational research, working in unison with clinicians. It’s going to take everybody working in sync.”

Saltzman has strived to bridge these two realms since his undergraduate days at Iowa State University, where he heard a talk by chemical engineer Richard C. Seagrave, Ph.D., that was an epiphany. “He gave a stunning lecture, a tour de force, about how the human body is just a very complex chemical plant,” Saltzman recalls. “He explained how the tools you have as a chemical engineer are exactly the right tools for understanding how this system works, and designing approaches for helping when the system fails.” Saltzman, an Iowa native, soon melded his long-standing interest in medicine with an affinity for engineering that he attributes to the pragmatic outlook of his grandparents, all Midwestern farmers.

In graduate school at the Massachusetts Institute of Technology (MIT), Saltzman created drug-impregnated implants from plastic-like polymers that slowly and steadily release medicines for long periods. This work is now helping patients in the form of Gliadel, a chemotherapy-infused wafer that neurosurgeons lay on the brain’s surface to battle the deadly tumors known as gliomas. While at MIT, Saltzman also worked with Joseph J. “Jay” Vacanti, M.D., of Massachusetts General Hospital, building tubular scaffolds that could be seeded with cells to sculpt new replacement blood vessels for patients with advanced vascular disease.

A fruitful collaboration with Christopher K. Breuer, M.D., assistant professor of surgery, is drawing on both of Saltzman’s areas of expertise. Since his MIT days, Saltzman has miniaturized his slow-release polymers into spherical nanoparticles that can be taken up directly by cells. By treating tissue scaffolds with particles that contain molecules to promote proper cell growth, Breuer and Saltzman are engineering better, stronger blood vessels than has previously been possible. In other projects with medical colleagues, Saltzman is testing nanoparticles to deliver vaccines for infectious disease, and drugs for cancer and fertility control.

Though biomedical researchers at Yale have independently adopted engineering approaches for decades, the 2003 founding of BME has given new vigor to interdisciplinary projects that team up top-notch biologists and engineers on Yale’s main campus with scientific and clinical experts at the School of Medicine. Saltzman, who oversees 12 faculty members as chair, says that Yale is an ideal venue to carry out the all-encompassing science at the heart of modern biomedical engineering. “Here, success isn’t measured by beating the guy in the lab next to you,” he says. “Yale’s a place that has a history of being collegial—a very congenial, collaborative place.”