The outer surface of biological membranes is usually negatively

charged (Cevc, 1990; Iglicˇ et al., 1997; McLaughlin, 1989). Also,

the outer membrane surface of the membrane daughter vesicles

released from different kind of cells such as red blood cells

(RBCs), platelets, and lymphocytes, as well as from apoptotic cells

(with negatively charged cardiolipin and phosphatidylserine in the

outer membrane layer) are negatively charged (Greenwalt, 2006;

Ha¨gerstrand and Isomaa, 1994; Ha¨gerstrand et al., 1999; Martinez

et al., 2005; Sorice et al., 2000).