He holds appointments in the MIT Department of Materials Science & Engineering and the Department of Biological Engineering, the Koch Institute for Integrative Cancer Research, and is a member of the steering committee for the Ragon Institute of MGH, MIT, and Harvard. His research is focused on the application of engineering tools to problems in cellular immunology and the development of new materials for vaccine and drug delivery. These efforts largely focus on cellular immunology and vaccine development for HIV and immunotherapy of cancer.