Evaluation of the Uptake of PLGA-PEG Nanoparticles by Human Cancer Cells

To investigate the patterns of uptake of PLGA-PEG nanoparticles by human cancer cells, FITC-labeled polymer nanoparticles (FPN) are prepared and their properties are characterized. The amount of internalized FPN is measured by flow cytometry after quenching the fluorescence of the membrane-bound nanoparticles with Trypan Blue. The total uptake of the FPN by COLO 320 HSR and SW837 human cancer cells is shown to be proportional to the nanoparticle concentration and incubation time over a period of 24 h. The highest intracellular accumulation of the FPN is observed at 1 or 4 h, depending on the cell type. The translocation of the biodegradable and biocompatible polymer nanoparticles into the cancer cells that we observe may be the mechanism for enhancing the efficiency of the anticancer drug by loading it into these nanocarriers owing to a prolonged increase in the intracellular concentration of the therapeutic agent and the facilitation of its interaction with intracellular targets.