1. Center for Drug Delivery and Nanomedicine and Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, 985830 Nebraska Medical Center, Omaha, Nebraska 68198-5830, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, Nebraska 68198-6805, and Supratek Pharma Inc., 215 Bvd. Bouchard, Suite 1315, Laval, Quebec H9S1A9, Canada