(338c) Membrane Lipid Asymmetry Regulates Nanoparticle-Induced Cell Membrane Damage in Red Blood Cells
AIChE Annual Meeting
Topical Conference: Environmental Aspects, Applications, and Implications of Nanomaterials and Nanotechnology
Tuesday, October 30, 2018 - 1:08pm to 1:27pm
Vesicle integrity was studied by encapsulating the self-quenching fluorescent probe, carboxyfluorescein, in vesicles and studying its leakage after exposure to 0.0001-0.01 g/L of ENMs at 37 °C. Confocal fluorescence microscopy performed on giant unilamellar vesicles (GUVs) was used to monitor nanoparticle effects on vesicle morphology. Forster Resonance Electron Transfer (FRET) experiments were employed to examine particle localization at the membrane. Finally, ENM-induced hemolysis was evaluated by measuring the absorbance of hemoglobin released from red blood cells after incubation with 0.01 g/L of nanoparticles at 37 °C.
Nanoparticle interactions with Vexo and Vcyto vesicles were drastically different. Vexo vesicles showed significant leakage after exposure to plain and amine-modified particles, but were not disrupted by carboxyl-modified and PEGylated particles. Conversely, none of the particles caused significant leakage in Vcyto vesicles as evidenced by a lack of significant leakage. In agreement, FRET experiments revealed significant localization of plain and amine-modified particles, but not carboxyl-modified and PEGylated particles, at the surface of the Vexo vesicles. Only minor localization with the Vcyto vesicles was observed for all particles. Similarly, GUV images indicated visual disruption of Vexo vesicles by plain and amine-modified ENMs. Importantly, hemolysis of red blood cells by ENMs was consistent with leakage assays using Vexo vesicles. Hemolysis was observed after the incubation of cells with plain and amine-modified particles, but not after incubation with carboxyl-modified and PEGylated particles. In conclusion, these results suggest that artificial vesicles mimicking the exofacial leaflet of the cell plasma membrane predict ENM-induced membrane damage in red blood cells and could have important implications in predicting the cytotoxicity of ENMs.