1. Department of Pharmaceutical Sciences, University of Pisa, Via Bonanno 6, 56126 Pisa, Italy, Division of Pharmacology and Chemotherapy, Department of Oncology, Transplants and Advanced Technologies in Medicine, University of Pisa, Via Roma 55, 56126 Pisa, Italy, Department of Bioorganic Chemistry and Biopharmacy, University of Pisa, Via Bonanno 33, 56126 Pisa, Italy, and Medical Department, Bracco Imaging spa, Via E. Folli 50, 20134 Milano, Italy