1. Department of Laboratory Medicine and Pathology, and Biomedical Engineering Institute, University of Minnesota, Minneapolis, Minnesota 55455.
2. Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455.
3. Present address: Advanced Tissue Sciences, La Jolla, California 92037.
4. Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota 55455.
5. Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455.
6. Biomedical Engineering Institute, University of Minnesota, Minneapolis, Minnesota 55455.
7. Department of Surgery, University of Minnesota, Minneapolis, Minnesota 55455.