Dr. Papaioannou received his medical degree from Loma Linda University in California where he graduated having been ranked in the top 10% of his class in medicine, surgery, and OB/GYN. He also scored in the top 10% in all 3 steps of the US medical licensing examination.  He was the recipient of the “George Hinshaw award” for outstanding performance and clinical ability in general surgery at Loma Linda University School of Medicine. This is the only surgical award given to one member of each graduating class. He continued his training with an internship and residency in internal medicine at Kettering Medical Center in Kettering, followed by a fellowship in hematology-medical oncology at Ohio State University in Columbus Ohio.

Since 2008, Dr. Papaioannou has been in private group practice with Hematology-Oncology of Dayton. Dr. Papaioannou has been married to his wife Vicki since 1989. Together they have four children, two daughters and two sons. When Dr. Papaioannou is not taking care of his patients, he enjoys traveling, listening to music, and hiking with his wife and children.