1. Institute of Biotechnology, ETH-Zürich, Hönggerberg, CH-8093 Zürich, Switzerland; Institute of Polymers, ETH-Zürich, CH-8092 Zürich, Switzerland; Swiss Federal Laboratories for Materials Testing and Research (EMPA), CH-8600 Dübendorf, Switzerland; and Swiss Federal Institute for Environmental Science and Technology (EAWAG), CH-8600 Dübendorf, Switzerland