Self-assembly of doxorubicin into gels

Self-assembly of doxorubicin into gels Elisamaria Tasca1*, Mauro Giustini1,2, Marco D’Abramo1, Luciano Galantini1,2, Gerardo Palazzo2,3 1 Chemistry Dept., “La Sapienza” University, P.le Aldo Moro 5, 00185-Rome, [Italy] 2 CSGI (O.U. of Bari), Chemistry Dept., University of Bari, 70126 Bari [Italy] 3 Chemistry Dept., University of Bari, Via Orabona 4, 70126-Bari, [Italy] *tasca.1542767@studenti.uniroma1.it The closely related anthracyclines doxorubicin (DX), daunomycin (DN) and epirubicin (EPI) in aqueous solution are present essentially as dimers at concentrations above or equal to 10-5M. However, DX, but not DN and EPI, in the presence of NaCl, at concentrations above a threshold value that depends also on the DX concentration, gives rise to gels [1-2]. The properties of these gels have been studied by UV-Vis, circular dichroism (Figure 1-A), steady-state and time resolved fluorescence (TCSPC - Figure 1-B) spectroscopy and SAXS (Figure 1-C), supported by MD simulations and fluorescence microscopy. The experimental results and the simulations suggest self-assembly of the somewhat distorted dimers in supramolecular aggregates, possibly in the form of fibrils, that would aggregate into larger structures to give the gels [3]. References [1] M. Giomini, A.M. Giuliani, M. Giustini and E. Trotta, Biophys. Chem., 1992 (45) 31. [2] E. Hayakawa, K. Furuya, T. Kuroda, M. Moriyama and A. Kondo, Chem. Pharm. Bull., 1991 (39) 1282. [3] M. Giustini, A.M. Giuliani, E. Tasca, M. D’Abramo, L. Galantini and G. Palazzo, manuscript in preparation.