ENVR 252 |
| We investigated whether multi-hydroxyl metallofullerenes can penetrate into erythrocyte and whether this potential transmembrane delivery requires aggregated nanostructure of these particles. Image of atomic force microscopy (AFM) and assay of inductively coupled plasma-mass spectrometry (ICP-MS) suggested that aggregated [Gd@C82(OH)22]n particles traversed through cytomembrane into cytoplasm. Aggregated Gd nanostructure belonged to small sphere with average diameter of ca 22.4±0.5 nm. Local distribution of hydroxyls brought about polar and nonpolar domains on particle surface, which induced Gd@C82(OH)22 to be an amphiphilic molecule with due hydrophilic and hydrophobic properties. Amphiphilic properties of these molecules promoted their mutual aggregation in water. In the process of aggregation, amphiphilic properties of aggregated nanoparticles were well maintained and, besides, hydrophilic and hydrophobic domains were also regularly distributed on the surface of [Gd@C82(OH)22]n particles. The amphiphilic nanoparticles attached externally to cytomembrane of erythrocyte might be effectively driven by hydrophobic effect when they directly contacted the cytomembrane of erythrocyte. The number of [Gd@C82(OH)22]n nanoparticles attached to the cytomembrane reached up to a certain critical threshold, a significant curvature tension of membrane would occur. The shape of cell was accordingly changed. Increased membrane tension triggered the sudden opening of specific pores as a result of cytomembrane response to nanoparticle effect and the [Gd@C82(OH)22]n nanoparticles gained entry to cell via these pores. This process was biologically independent of caveolar-mediated endocytosis or transportation pathway via ion channels. |
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Environmental Behavior and Fate of Manufactured Nanomaterials
6:00 PM-8:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Division of Environmental Chemistry |