1. Department of Bioengineering, University of Illinois, Chicago, Illinois 60607-7052
2. Advanced Materials and Nanobiotechnology Laboratory, Department of Biomedical and Pharmaceutical Sciences, Center for Targeted Drug Delivery, Chapman University, Irvine, California 92618-1908
3. Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
4. Institute of Technical Sciences of the Serbian Academy of Sciences and Arts (SASA), Knez Mihailova 35/IV, 11000 Belgrade, Serbia