Britton Chance: Biophotonics visionary, Olympic gold medalist, and inspiring mentor

It seems fitting that the gold-medal-winning sailboat of the 1952 Summer Olympics in Helsinki, Finland, was named, “Complex II.” The boat’s skipper, after all, was Britton Chance, the holder of two doctoral degrees—one in physical chemistry, the other in physiology—who would go on to become a distinguished academic and medical imaging pioneer, among many other achievements in science and medicine over the course of his long career.

Chance won nearly every major prize in science in the US and internationally, save for the Nobel Prize. Up to his death in 2010, he remained a passionate sailor and working scientist. Almost his entire academic career, beginning with undergraduate studies and his first PhD degree, was spent at the University of Pennsylvania (U. Penn). He completed a second PhD degree at Cambridge University and served a four-year fellowship at Massachusetts Institute of Technology (MIT).

In time, Chance would be recognized as a founder of the field of biophotonics, and for six decades he was a mentor to students inspired by his work.

“I’ve always worked in biomedical research, but when the area of biophotonics started taking root in the early 90s, Britton reached out and asked if we would be able to integrate molecular imaging into the whole idea of near-infrared (NIR) optical imaging,” recalls Samuel Achilefu, a professor of radiology and biomedical engineering at Washington University School of Medicine. It was a new concept for him because he hadn’t been working in NIR optical imaging. “Working with Britton was a life-changing experience.”

Achilefu received the 2019 SPIE Britton Chance Award in Biomedical Optics.

Chance’s passion for invention appeared early in life, and it was built on his zest for sailing. At age 17, he devised and patented an automatic ship steering device that incorporated a novel light-based servomechanism.

“Brit used light reflected from a mirror coupled to a compass needle to achieve this goal; when the ship got off course, both the compass needle and the reflected light would move,” wrote Arjun G. Yodh and Bruce J. Tromberg in a tribute to Chance published in a special issue of the Journal of Biomedical Optics in 2000. The device relied on photodetectors to register the motion of the light beams, and a feedback signal redirected the ship steering mechanisms. Yodh is now a professor of physics and astronomy at U. Penn, and Tromberg is director of the National Institute of Biomedical Imaging and Bioengineering, part of the US National Institutes of Health.

In an autobiographical account of his early life and inventions, Chance wrote, “The proverbial ‘frontiers of knowledge’ seemed near indeed, and I was eager to explore them.”

After completing his first PhD, Chance’s interest in biochemistry merged with his interest in light. Working at U. Penn, he developed a stop-flow apparatus for the study of enzymes and their intermediates. He used beams of light to interrogate the changing compositions of the flowing sample and then identified molecules by their absorption spectra.

In an online tribute to Chance, the American Philosophical Society notes that his stop-flow apparatus allowed observation of rapid mixtures by detecting color variation, which in turn resulted in “a profound impact on scientists’ abilities to understand cell metabolism and energy conversion.”

A tribute to Chance published in a special issue of the Journal of Biomedical Optics in 2000

Chance’s imaginative use of electricity, electronics, and light led to his recruitment to MIT’s Radiation Laboratory during World War II. There, he developed submicrosecond circuits for guns and bombs. By the end of the war, he was directing a 300-member research team at the “Rad Lab.”

But by 1949, he was back at U. Penn as director of the Eldridge Reeves Johnson Research Foundation, which was devoted to biomedical physics. He built on his earlier work using light to study enzymes, now to include cells, tissues, and eventually the entire human body.

Foremost in his work in biochemistry, perhaps, was Chance’s study of the function of mitochondria in human cells—a hugely complex task at the time. After he and colleagues learned to separate the organelle and suspend it in a chemical cocktail that preserved its metabolic activity, Chance’s dual-beam spectrometer allowed observation of mitochondria in ATP synthesis.

“The device rapidly toggled between two beams of light with differing wavelengths,” Yodh and Tromberg wrote. “Typically, the wavelength of one beam was chosen to coincide with the peak absorption of a chromophore such as cytochrome-a 3; the other wavelength was spectrally shifted by a small amount in order to provide a background measurement near the baseline of the absorption feature with similar scattering contributions.”

By the late 1970s, Chance’s work had evolved to studying nuclear magnetic resonance (NMR) for spectroscopic study of the human brain and limbs. In his APS autobiography, Chance recounted how NMR “showed that we could study metabolic control in a very elegant fashion. That research went right back to my studies on mitochondria…now we could see it in the real world of functioning muscles and brain. It was wonderful because we had always wanted to show that those things really happened in human skeletal muscle rather than in, say, a rat’s brain.”

Chance was put off, however, by the high cost of NMR. Its close cousin, magnetic resonance imaging (MRI), was taken up and developed by other researchers into the clinical tool used today for imaging deep tissue metabolic activity. He switched his focus to NIR technology.

A retrospective in Science after his death in 2010 notes how Chance “showed that scattered near-infrared light pulses could not only measure the dynamics of oxy- and deoxyhemoglobin levels in performing muscles, but also reveal and locate tumors and cancerous tissue in muscles and breast as well as injury in the brain. Because changing patterns of oxy- and deoxyhemoglobin in the brain reflect cognitive activity, the applications of his diagnostic approach widened to include assessing neuronal connectivity in premature babies.”

Of this shift in focus that would carry through to the end of his career, “Once again, Brit has been a central figure in the development of a new field,” Yodh and Tromberg wrote. “He has worked tirelessly to advance our understanding of biology, instrumentation, and medicine by asking tough questions, making countless suggestions, and bringing together basic scientists, engineers, and clinicians in dozens of scientific meetings.”

William G. Schulz is the Managing Editor of Photonics Focus.