Andersen, Alina Joukainen3; Windschiegl, Barbara1; Ilbasmis-Tamer, Sibel7; Degim, Ismail T.7; Hunter, Alan Christy5; Andresen, Thomas L.1; Moghimi, Seyed Moein6
1 Department of Micro- and Nanotechnology, Technical University of Denmark2 Colloids and Biological Interfaces, Department of Micro- and Nanotechnology, Technical University of Denmark3 Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics, Center, Technical University of Denmark4 Gazi University5 University of Manchester6 unknown7 Gazi University
Carboxylated (4%) multi-walled carbon nanotubes were covalently functionalized with poly(ethylene glycol)1000 (PEG1000), PEG1500 and PEG4000 with a PEG loading of approximately 11% in all cases. PEG loading generated non-uniform and heterogeneous higher surface structures and increased nanotube width considerably, but all PEGylated nanotube species activated the complement system in human serum equally. Increased PEG loading, through adsorption of methoxyPEG2000(or 5000)-phospholipid conjugates, generated fewer complement activation products; however, complement activation was never completely eliminated. Our observations address the difficulty in making carbon nanotubes more compatible with innate immunity through covalent PEG functionalization as well as double PEGylation strategies. From the Clinical EditorComplement-mediated toxicity is a major limiting factor in certain nanomedicine applications. This study clarifies that PEGylation of carbon nanotubes is unlikely to address this complication.
Nanomedicine: Nanotechnology, Biology and Medicine, 2013, Vol 9, Issue 4, p. 469-473