Cm120 biotwin transmission electron microscope

The shape and morphology of the nanogels
were characterized by an
FEI CM120 Bio Twin Transmission Electron Microscope (TEM) (Hillsboro,
OR). One drop of the nanogel sample was dropped onto 200-mesh carbon
lacey-coated copper grids and stained with 1% uranyl acetate solution,
followed by air-drying at room temperature for a few minutes. The
excess solution was removed using filter paper. Particle size distribution
was performed using ImageJ (NIH, Bethesda, MA).

For exosomes isolation, supernatant collected from ovarian cancer cells cultured in DMEM containing 10% Exosome-free FBS (System Biosciences, USA) for 48 h was centrifuged at 300 × g for 10 min, 3000 × g for 30 min and 10,000 × g for 30 min. Then, the supernatant was passed through 0.22-μm pore PES filters (Millipore). Ultracentrifugation was performed at 100,000 × g for 70 min using an Optima XE-90 Supercentrifuge (Beckman, Germany) to enrich the exosomes, and the pellet was rinsed using 30 ml of PBS. Finally, the exosomes were collected by ultracentrifugation at 100,000 × g for 70 min.
Isolated exosomes were mixed with 4% paraformaldehyde. exosomes were then dropped onto formvar carbon-coated electron microscopy grids and fixed with 1% glutaraldehyde for 10 min. Samples were negatively stained with 2% uranyl acetate solution. Images were obtained using Philips CM120 BioTwin transmission electron microscope (TEM) (FEI Company, USA).
Nanoparticle tracking analysis (NTA) was performed by Malvern Zetasizer Nano ZS-90 (Malvern Instruments Ltd., UK) following the manufacturer’s instructions. The exosomes were diluted in PBS. The mean particle size and size distribution were analyzed by dynamic light scattering method using the Malvern Zetasizer Nano ZS-90.

The shape and morphology of the nanogels were characterised using an FEI CM120 Bio Twin Transmission Electron Microscope (TEM) (Hillsboro, OR, USA). One drop of the nanogel sample was dropped onto 200-mesh carbon lacey-coated copper grids and stained with a 1% uranyl acetate solution, followed by air-drying at room temperature for a few minutes. The excess solution was removed using filter paper. Particle size distribution was performed using Image J 1.54h (NIH, Bethesda, MA, USA).

The shape and morphology of the nanogels obtained under the optimal conditions were characterised using a Philips/FEI CM120 BioTwin Transmission Electron Microscope (TEM) (FEI, The Netherlands), where one drop of the nanogel sample was placed on a 200-mesh carbon-coated copper grid and stained with 1% uranyl acetate solution, followed by air-drying at room temperature for a few minutes. Excess solution was removed using filter paper. The particle size distribution was determined on the TEM images using ImageJ (US NIH, Bethesda, MD, USA) with a sample size of n = 107 particles and a Gaussian fit was applied to the histograms. Two separate TEM images were used to achieve a sufficient number of measurements for the particle size analysis.