1. Department of Biology, Point Loma Nazarene University, San Diego, California 92106;
2. Departments of 2Biomedical Engineering,
3. Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093
4. Radiology,
5. Materials Science and Engineering, and
6. Macromolecular Science and Engineering, Case Western Reserve University, Schools of Medicine and Engineering, Cleveland, Ohio 44106;