Liposomes were prepared by the thin-film method, where DPPC:DSPC were dissolved in ethanol at a concentration of 10 mg/mL. A series of different ratios of the two phospholipids were prepared, to which 5% w/w DSPE-PEG with respect to the total lipid content was added for enhanced colloidal stability. A thin, lipidic film was consequently obtained by removing ethanol using a rotary evaporator. The lipidic film was rehydrated with phosphate buffer (10 mM, pH 7.4) to a concentration of 10 mg/mL of lipids, yielding a cloudy suspension. Small, monodispersed liposomes were obtained by sequential extrusion through polycarbonate membranes of decreasing size (800 μm, 400 μm, 200 μm, and 100 μm) using a mini-extruder (Avanti Polar Lipids Inc, US). Extrusion was conducted at 41 ± 3 °C with a minimum of 10 extrusion cycles per membrane.