1. Department of Biomedical Engineering; Case Western Reserve University; 10900 Euclid Avenue Cleveland OH 44106 USA
2. Department of Chemistry; University of Massachusetts; 710 North Pleasant Street Amherst MA 01003 USA
3. Département Chimie Physique; École Nationale Supérieure de Chimie de Biologie et de Physique 16; avenue Pey Berland 33607 PESSAC CEDEX France
4. Department of Orthopaedic Surgery; Case Western Reserve University; 10900 Euclid Avenue Cleveland OH 44106 USA