Biophysical Society Bulletin | January 2022

InMemoriam

he became fascinated by macromolecular physical chemistry as he earned his Bachelor of Science degree from the University of Chicago in 1966 and PhD in crystallography/biochemistry from the University of Pittsburgh in 1970. This was followed by postdoctoral research at Columbia University andMassachusetts Institute of Technology (MIT; with Alex Rich ). During his five years at SUNY Albany as assistant professor, Ned built Holliday-junc- tion constructs and, with various ideas about sticky polymer ends and branching, he was well on his way to developing novel

the area experimentally in his laboratory. He built a cube-like ob- ject, the first 3D DNAmolecule, and then developed a solid-sup- port method to construct a DNA truncated octahedron. The catenated nature of these molecules led him to realize that DNA is an ideal component for topological targets, leading to the discovery of an RNA topoisomerase, and the first example of the synthetic topology holy grail, Borromean rings. Realizing that periodic matter required components stiffer than conventional branched junctions, he established the stiffness of the DNA dou- ble crossover motif and related species; these molecules enabled both the first 2D periodic lattice of DNA and the first DNA-based nanomechanical device. This device was followed by a robust sequence-dependent device, incorporated into a 2D DNA lattice. He used these techniques to construct walkers that couldmove in designed pathways on DNA surfaces, and ultimately a DNA assembly line that picked up and delivered cargo. In recent work, Seeman began to use these tools to assemble nanoelectronic structures, in which products are built from components that are no larger than individual molecules. Seeman was the founding president of the International Society for Nanoscale Science, Computation, and Engineering (ISNSCE). He received the American Chemical Society’s Nichols Medal as well as the Sidhu Award from the Pittsburgh Diffraction Society, a Popular Science Magazine Science and Technology Award, the Feynman Prize in Nanotechnology, a Discover Magazine Emerging Technology Award, a Nanotech Briefs Nano50 Innovator Award, theWorld Technology Network Award in biotechnology, the Alex- ander Rich Lectureship fromMIT, the Frontiers of Science Award from the Society of Cosmetic Chemists, the Nanoscience Prize of the ISNSCE, the Rozenberg Tulip Award in DNA Computing, the Einstein Professorship of the Chinese Academy of Sciences, a Distinguished Alumnus Award from the University of Pittsburgh, the Jagadish Chandra Bose Triennial GoldMedal, and the Benja- min FranklinMedal in Chemistry. In 2010, Seeman was awarded the Kavli Prize in Nanoscience, which he shared with Donald Eigler of IBM’s Almaden Research Center. Ned remained humble and loyal to his friends, colleagues, and students as his recognition rose and accolades accrued. He was not swayed by trends of the moment or fancy talk. I admired his honesty and intelligence. Most of all, I was touched by the sweet person he was under his rugged exterior. As I think back on somany years of us as colleagues and friends, I recall many great talks about our shared interest in DNA topology, Greenwich Village walks (see photograph), afternoon coffees, and arguments or discussion about plays and books. Ned was full of life and am- bition, and always knewwhere he was going. I hope he is making a ruckus where he is now, and continuing to pour his wisdom, wit, and heart out to his new neighbors. — Tamar Schlick

In a cafe in Greenwich Village in New York City, from left to right: Ned Seeman, Wilma Olson,and Tamar Schlick. self-assembling DNA junctions. This work led to a collaboration with Neville Kallenbach , who eventually offered Ned an invitation to join the faculty at New York University’s (NYU’s) Department of Chemistry in 1988, where Kallenbach became Chair. By Ned’s own testimony, the open environment of New York and NYU suited him, and he thrived as he was able to pursue, with many wonderful students, his vision in structural DNA technolo- gy, synthetic DNA topology, and eventually DNA nanomechanical devices. On our NYU Department of Chemistry website, Ned’s professional contributions and impact are summarized well: Seeman, the Margaret and Herman Sokol Professor of Chemistry at NYU, founded and developed the field of DNA nanotechnol- ogy—which is now pursued by over 250 laboratories across the globe—more than 35 years ago. His creations allowed him to arrange DNA building blocks to form specific molecules with precision through self-assembly—similar to the way a robotic automobile factory can be told what kind of car tomake. See- man’s work led the Christian Science Monitor to conclude that nanotechnology may have found its Henry Ford . Inspired by Escher’s woodcut, Depth , in the early 1980s, See- man combined the novel notion of branched DNA with directed sticky-ended associations to suggest that multiply-connected objects and periodic networks of DNA could be assembled with precise structural features in two (2D) or three dimensions (3D). After conceiving this notion, he implemented a program to pursue

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