To verify the structure of liposomes as well as determining the effect
of gelatin on integrity of the liposomes cryo transmission electron microscopy
(TEM) images were prepared. The liposome dispersions containing 4% (W/W) of
fenofibrate either prepared with PBS (as a control) or solution of gelatine
dissolved in PBS were diluted in PBS to a concentration of 10 mg/mL and applied
to a glow discharged Quantifoil sample support grid. The grids (2/2) were glow
discharged for 10 s in a H2 and O2 gas mixture and the dispersion was blotted
from one side at 4 °C and humidity of 100% for 8-10 s using a Vitrobot (FEI,
Hillsboro, Oregon). Directly after blotting, the grid was dipped into liquid
ethane. The grids were observed in a Titan Krios microscope (FEI, Hillsboro,
Oregon) equipped with a Quantum 963 SE energy filter operated at 200 kV and
liquid nitrogen (LN) temperature. Zero loss filtered images were taken at 64000×
magnification (pixel size 2.2 A) using a 2k Ultrascan Quantum CCD camera.