1. Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
2. Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
3. Department of Periodontics and Oral Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
4. Department of Pathology, Medical School, University of Michigan, Ann Arbor, Michigan 48109, United States
5. Macromolecular Science and Engineering Center, University of Michigan, Ann Arbor, Michigan 48109, United States
6. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States