Arnold Caplan

Arnold Irving Caplan (January 5, 1942 – January 10, 2024) was an American stem cell biologist and professor at Case Western Reserve University. His research involved clinical applications of mesenchymal stem cells (MSCs) in treating human diseases.

Early life and education Arnold Irving Caplan was born on January 5, 1942, in Chicago, Illinois.

He earned his Bachelor of Science (B.S.) degree in Chemistry from the Illinois Institute of Technology and completed his Ph.D. in Biochemistry at Johns Hopkins University School of Medicine.

Career Caplan joined Case Western Reserve University as an assistant professor in 1969, and was promoted to professor in 1981. He served as the founding director of the university's Skeletal Research Center. He held secondary appointments at the School of Engineering and the School of Medicine. Caplan performed research involving isolating MSCs from adult bone marrow in the late 1980s. This research helped demonstrate MSCs' ability to modulate the immune system, inhibit programmed cell death and scar formation stimulate blood vessel formation, and promote tissue-specific stem cell growth. He trained over 150 researchers during his career.

Personal life Arnold Caplan was married to Bonnie Caplan for 58 years. They had two children and 6 grandchildren.