[1] Univ Montpellier, Lab Colloides Verres & Nanomateriaux, Montpellier 5, France
[2] CEA LETI, Div Technol Biol & Hlth, F-38054 Grenoble, France
[3] Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA
[4] Tech Univ Denmark, MIC, Dept Micro & Nanotechnol, DK-2800 Lyngby, Denmark
[5] Univ Illinois, Dept Cell & Dev Biol, Urbana, IL 61801 USA