Fullerene, the third allotrope of carbon, has been referred to as a "radical sponge" because of its powerful radical scavenging activities. However, the hydrophobicity and toxicity associated with fullerene limits its application as a therapeutic antioxidant. In the present study, we sought to overcome these limitations by generating water-soluble nanoformulations of fullerene (C(60)). Fullerene (C(60)) was formulated with poly(N-vinyl pyrrolidine) (PVP) or poly(2-alkyl-2-oxazoline)s (POx) homopolymer and random copolymer to form nano-complexes. These C(60)-polymer complexes were characterized by UV-vis spectroscopy, infrared spectroscopy (IR), dynamic light scattering (DLS), atomic force microscopy (AFM) and transmission electron microscopy (TEM). Cellular uptake and intracellular distribution of the selected formulations in catecholaminergic (CATH.a) neurons were examined by UV-vis spectroscopy, immunofluorescence and immunogold labeling. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the ability of these C(60)-polymer complexes to scavenge superoxide. Their cytotoxicity was evaluated in three different cell lines. C(60)-POx and C(60)-PVP complexes exhibited similar physicochemical properties and antioxidant activities. C(60)-poly(2-ethyl-2-oxazoline) (PEtOx) complex, but not C(60)-PVP complex, were efficiently taken up by CATH.a neurons and attenuated the increase in intra-neuronal superoxide induced by angiotensin II (Ang II) stimulation. These results show that C(60)-POx complexes are non-toxic, neuronal cell permeable, superoxide scavenging antioxidants that might be promising candidates for the treatment of brain-related diseases associated with increased levels of superoxide.
|Original language||English (US)|
|Number of pages||12|
|State||Published - May 2011|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUK-F1-029-32
Acknowledgements: This study was supported by the Nanomaterials Core Facility of the Nebraska Center of Nanomedicine supported by NIH COBRE grant RR021937 (awarded to A.V.K.). We also gratefully acknowledge the assistances of UNMC Nanoimaging Core Facility and the Core Electron Microscopy Research Facility (CEMRF) in the AFM and TEM experiments and support by the King Abdullah University of Science and Technology (KAUST Award No. KUK-F1-029-32, partial salary support for R.L.).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.