1. Drug Formulation & Delivery Group, Department of Chemistry and Applied BioSciences, Swiss Federal Institute of Technology Zurich (ETH Zurich), Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland, and Laboratory for Surface Science and Technology, Department of Materials, Swiss Federal Institute of Technology Zurich (ETH Zurich), Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland