1. Particle Technology Laboratory, Institute of Process Engineering; Department of Mechanical and Process Engineering, ETH Zurich; Sonneggstrasse 3 CH-8092 Zurich Switzerland
2. Department of Environmental Health; Harvard University; 665 Huntington Ave. Boston 02115 MA USA
3. Drug Formulation & Delivery, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich; Wolfgang-Pauli-Strasse 10 CH-8093 Zurich Switzerland
4. Institute of Diagnostic and Interventional Radiology, University Hospital Zurich; Raemistrasse 100 CH-8091 Zurich Switzerland