Transmission electron microscopy (TEM) was employed to shed light on the vesicle shape of LIPO. Briefly, samples for TEM analyses were negatively stained, depositing a sample drop on a TEM screen covered with a Formvar film (Media System Lab S.r.l., Macherio, MB, Italy).31 (link) The excess drop was removed from the screen after 1 min with filter paper to keep a light veil of sample on the supporting substrate.
A drop of 2% phosphotungstic acid was placed on the screen for 1 min and then removed with filter paper to surround the nanosystems deposited on the screen and adhere to their surface. Then, the screen was observed with a ZEISS EM 910 transmission electron microscope (Carl Zeiss Microscopy, GmbH, Munich, Germany). Furthermore, some samples prepared by the same procedure were observed by a TALOS L120C G2 Transmission Electron Microscope (Thermo Fisher Scientific, Eindhoven, Nederland), equipped with a 4k × 4K Ceta CMOS camera, providing a large field-of-view and live digital zooming with high sensitivity and high speed.
A drop of 2% phosphotungstic acid was placed on the screen for 1 min and then removed with filter paper to surround the nanosystems deposited on the screen and adhere to their surface. Then, the screen was observed with a ZEISS EM 910 transmission electron microscope (Carl Zeiss Microscopy, GmbH, Munich, Germany). Furthermore, some samples prepared by the same procedure were observed by a TALOS L120C G2 Transmission Electron Microscope (Thermo Fisher Scientific, Eindhoven, Nederland), equipped with a 4k × 4K Ceta CMOS camera, providing a large field-of-view and live digital zooming with high sensitivity and high speed.
