1. Colorado Center for Nanomedicine and Nanosafety, Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA;
2. Department of Physics and Astronomy, Clemson University, Clemson, SC, USA;
3. Clemson Nanomaterials Center and Comset, Clemson University, Anderson, SC, USA;
4. Materials Science and Engineering, Indian Institute of Technology, Gandhi Nagar, India