He received his Bachelor's degree in chemical engineering from the University of Pennsylvania before joining Merck Research Laboratories to conduct bioprocess engineering research. He received his PhD from the University of Wisconsin–Madison Department of Chemical and Biological Engineering in 2008 and completed an American Cancer Society postdoctoral fellowship in chemical engineering at the Massachusetts Institute of Technology. Metallo received the Biomedical Engineering Society Rita Schaffer Young Investigator Award in 2012. He was a 2013 Searle Scholar.