2.4. Characterization of Liposomes

Liposomes’ hydrodynamic diameter, polydispersity index (PdI), and zeta-potential were determined by Dinamic Light Scattering (DLS) and Electrophoretic Light Scattering (ELS), using a Zsizer Nano series ZS90 (Malvern Instruments, Malvern, UK). All samples were diluted 10-fold with deionized water, and an average of three measurements at stationary level was taken. A Haake temperature controller kept the temperature constant at 25 °C.

Morphological characterization was achieved by using the transmission electron microscopy (TEM) CM12 from Philips with an accelerating voltage of 80 kV. The aqueous dispersion was diluted 10-fold in deionized water, and 10 μL was applied to a 150-mesh carbon film-covered copper grid. To obtain a thin film, excess sample was eliminated from the grid with a filter paper. After that, 5 μL of phosphotungstic acid solution (1% w/v in water) was dropped onto the grid as a staining medium and the excess solution was removed with a filter paper. Samples were dried for 3 min, after which they were examined with the electron microscope and photographed at an accelerating voltage of 80 kV.