Mary Bartlett Bunge, Ph.D.

It is with our deepest sorrow that we inform you of the death of our beloved friend and colleague Dr. Mary Bartlett Bunge, who passed away on February 17, 2024, at age 92. Mary was a very special person and a dedicated scientist who, since 1989, has been an important member of The Miami Project to Cure Paralysis and our University of Miami academic community. Her friends and colleagues at the Miller School of Medicine are expressing sorrow for her passing and appreciation for her many contributions.

“Dr. Mary Bunge was an exceptional scientist and visionary with a passion for developing novel strategies to repair the nervous system,” said W. Dalton Dietrich, Ph.D., scientific director of The Miami Project and senior associate dean for discovery science. “Her research was instrumental in allowing scientists to critically evaluate Schwann cell transplantation in people living with spinal cord injury.”

“My respected and revered colleague of 35 years has left our team with an unfillable void,” said Barth A. Green, M.D., chair of The Miami Project and executive dean for global health and community service. “Mary was not just a world-renowned scientific innovator and mentor to thousands of colleagues and students, but also a role model in leadership, thereby distinguishing herself as one of a kind. In fact, the term ‘role model’ should have been embroidered on her laboratory coat.”

“Dr. Mary Bunge was a true neuroscience pioneer, paving the way for countless careers in discovery science,” said Marc Buoniconti, senior director for advocacy and donor relations at The Miami Project. “Her lifelong dedication to the University of Miami and The Miami Project’s mission of seeking a cure for paralysis has produced truly groundbreaking research that will change lives for those living with paralysis. I really enjoyed our friendship and conversations, she will be greatly missed by me and all who knew her.”

“Mary’s passing represents an incredibly sad time for The Miami Project, neurosurgery faculty and staff, and all her trainees,” said Allan D. Levi, M.D., Ph.D., professor and chair of neurological surgery. “Her research on Schwann cells and spinal cord injury was an inspiration for countless scientists, including myself.”

“Dr. Mary Bunge combined precision and flair in her scientific work, which was characterized by the finest quality, especially in her scientific images,” said James D. Guest, M.D., Ph.D., professor of neurological surgery. “This extended from her career-long love of electron microscopy and, in parallel, visual arts. She imbued this passion for excellence and detail into a generation of neuroscientists. Her work elevated the entire spinal cord injury field.”

As a child, Mary Bartlett began developing her passion for biology while observing tadpoles swimming around her, and she questioned how they developed into frogs. During her junior college year, she was further inspired by a summer school in Bar Harbor, Maine, where she was first exposed to tissue culture. After graduating from Boston’s Simmons College in 1953, she accepted an invitation to graduate school at the University of Wisconsin Medical School where she graduated with a master’s degree in medical physiology in 1955 and her doctorate in 1960.

While at the University of Wisconsin, she met a medical student named Richard Bunge, whom she married and who shared her career. Working together, they published the first evidence of remyelination by oligodendrocytes in the spinal cord in 1961. Together, they moved to Columbia University in New York, where they began their career-long work on the biology of Schwann cells, and where their two sons, Jonathan and Peter, were born. Mary was one of the earliest to master electron microscopy, which combined her passion for cell biology with artistic expression and allowed her to observe synapses in tissue culture. After moving to Boston for a sabbatical at Harvard, they moved to St. Louis in 1970 to accept faculty positions at Washington University School of Medicine where, in 1974, Mary was promoted with tenure to associate professor of cell biology, neurological surgery, and neurology and, in 1978, became professor.

During their years in St. Louis, Mary and her research team made several important discoveries while studying Schwann cells in tissue culture and their ability to wrap around peripheral axons to form the myelin sheath that acts to increase the speed of impulse conduction down the axon. Through their meticulous use of tissue culture, methods were found to isolate Schwann cells from neurons which led to new hypotheses regarding repairing the nervous system after injury. Based on this work, the Bunge laboratory then focused on determining whether Schwann cell transplantation into the injured spinal cord would promote successful axonal regeneration by making the injured tissue be more permissive for successful axonal growth.

Mary mentored a succession of graduate students and postdoctoral fellows who paved the way through translational studies for current and future FDA-approved clinical trials using autologous human Schwann cells as a novel strategy to repair the spinal cord and peripheral nerves after severe trauma. Richard passed away in 1996, but Mary continued the work through to its clinical realization to support recovery in people after spinal cord injury. Together, they greatly elevated the scientific standing of The Miami Project, which was formed in 1985.

Mary received many national and international honors during her career, including the Wakeman Award for spinal cord injury repair, and she was a three-time recipient of the Javits Neuroscience Investigator Award from the National Institute of Neurological Disorders and Stroke. She was elected chair of the of the Society for Neuroscience Development of Women’s Careers in Neuroscience Committee from 1994-2002. In 2000, she received the Mika Salpeter Women in Neuroscience Lifetime Achievement Award for her leadership in advancing the careers of women in neuroscience. In 2001, she received the Christopher Reeve Research Medal for Spinal Cord Injury Repair. She was elected to the National Academy of Sciences Institute of Medicine and was awarded the Health Care Hero Lifetime Achievement Award by the Greater Miami Chapter Chamber of Commerce.

Mary also received the Christine Lynn Distinguished Professor in Neuroscience Award in 2003 and the Lois Pope LIFE International Research Award in 2005. Upon receiving this award, she donated the money to the University of Miami to establish a lecture series to bring prominent women researchers doing groundbreaking work in cell biology to serve as role models to our campus annually. In 2012, Dr. Bunge received the University of Miami Faculty Senate Distinguished Faculty Scholar Award. The ASIA society awarded Richard and Mary with the lifetime achievement award in 2018. On February 6, 2024, the 19th Annual Mary Bartlett Bunge Distinguished Women in Cell Biology Lecture was held. Mary listened to this special lecture, demonstrating the enduring passion for science that never left her.

In addition to these many accomplishments and honors, Mary was an incredible teacher and mentor. She trained numerous graduate and postdoctoral fellows who went on to become leaders in the fields of cell biology, neuroscience, and Schwann cell transplantation. She will be greatly missed by everyone who knew her and had the privilege of learning from this special scholar who contributed so much to her scientific field, The Miami Project and the University of Miami.

Development of Combination Strategies to Repair the Injured Spinal Cord

The goal in my laboratory has been to foster regeneration of axons across and beyond the area of spinal cord injury (SCI) since coming to The Miami Project.

To improve axon regeneration after SCI, we have investigated Schwann cell transplantation in combination with a steroid, increases in cyclic AMP levels, lessening formation of proteoglycans (molecules that inhibit axon growth), olfactory ensheathing cell transplantation, and provision of neurotrophic factors in various ways (including genetically modifying Schwann cells to improve their neurotrophic factor secretory capability).  Both complete spinal cord transection and contusion models have been utilized.  We are studying gene differences between neurons that are able to regrow onto a Schwann cell bridge placed in the area of injury and those that do not grow onto the bridge.  Currently we are testing ways in which to modify the spinal cord-Schwann cell implant interfaces  for improved permissivity for axons to enter and exit the implant and clinically relevant biomaterials and conduits in which to transplant Schwann cells for improved survival and alignment.

A contribution of my laboratory has been to introduce the novel use of a Schwann cell bridge across a complete transection gap in the adult rat spinal cord to be able to identify regenerated axons.  The combination strategies we have evaluated have improved outcome consistently in both lesion models compared to Schwann cell transplantation alone.  For example, when neurotrophins are introduced along with Schwann cells, there are far more regrowing fibers and an increased variety of fibers in the implant, including those from distant neuronal somata positioned in the brainstem.  That combination strategies are more effective than Schwann cell implantation alone is undoubtedly, at least in part, due to the many and varied reactions of the spinal cord tissue to injury.