Tecnai g2 spirit biotwin icorr

A percutaneous liver biopsy was taken after local anaesthesia with a cutting-type 16-gauge needle. Parts of biopsies of 1.8–20 mm were cut into 1 mm³ blocks and were transferred to a 1.5% glutaraldehyde, 0.067 M cacodylate buffer (pH 7.4) and 1% sucrose (mOsmol 320) for 1 h. After washing in cacodylate buffer, tissue blocks were postfixed in 1% OsO4 with 0.1 M phosphate buffer (pH 7.4) for 1 h, followed by ethanol dehydration and embedding in Epon. LM sections of 2 µm thickness were stained with toluidine blue. EM sections were cut at a thickness of 60 nm and were contrasted with lead and uranyl and studied with a FEI Tecnai G2 Spirit BioTWIN iCorr. Microscopical observations with LM started at low magnifications (4–10×) to supervise larger areas of tissue with a large number of cells. Also, the transmission electron microscopy (TEM) observations started at 48× magnification, allowing to survey about 250 parenchymal cells in one image, prior to the use of higher magnifications up to a maximum of 90,000×. When necessary, a tissue block was further trimmed to select the well-perfused part of the tissue for detailed TEM investigation.

The size, PdI, and zeta potential of the nucleic acid-lipid or nucleic acid-polymer complexes were investigated using dynamic light scattering methods using a Zetasizer Nano ZSP (Malvern Instruments, Worcestershire, UK). In brief, 800 μL of the nucleic acid-vector complex solution (formed in non-supplemented cell culture medium) was used for the measurements, which were carried out at a fixed angle (173° backscattering). Indicated cuvettes for electrophoretic measurements (DTS1070, Malvern Instruments) were used. All the samples were measured at 20°C ± 3°C and the measurements were performed in triplicate (n = 3).
The morphology of the lipid complexes was examined using TEM. In brief, a 5 μL solution of each lipid complex was loaded onto a 300-mesh copper grid coated with a carbon support film. The grids were then air-dried overnight and examined with a TEM (Tecnai G2 Spirit BioTWIN iCorr, FEI, Hillsboro, OR) operated at 120 kV. Imaging was carried out using a WA-Veleta camera (EMSIS, Münster, Germany).