a
Department of Biomedical Engineering, Tufts University, 4 Colby St., Medford, USA
E-mail: david.kaplan@tufts.edu
;
Fax: +1-617-627-3231
;
Tel: +1-617-627-3251
b
Department of Chemical and Biological Engineering, Tufts University, Medford, USA
c
Department of Mechanical Engineering, Tufts University, Medford, USA
d
Department of Nanomedicine, The Methodist Hospital Research Institute, Houston, USA