[1] MIT, David H Koch Inst Integrat Canc Res, Cambridge, MA 02139 USA
[2] MIT, Dept Chem Engn, Cambridge, MA 02139 USA
[3] MIT, Div Hlth Sci Technol, Cambridge, MA 02139 USA
[4] Childrens Hosp, Dept Anesthesiol, Boston, MA 02115 USA
[5] Joslin Diabet Ctr, Sect Islet Cell & Regenerat Biol, Div Res, Boston, MA 02215 USA
[6] Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA
[7] Iowa State Univ, Dept Chem & Biol Engn, Ames, IA 50011 USA