Influence of purity and surface oxidation on cytotoxicity of multi-wall carbon nanotubes with human neuroblastoma cells.
Nanomedicine. 2009 Mar 30;
Authors: Vittorio O, Raffa V, Cuschieri A
There are conflicting data concerning the safety and biocompatibility of carbon nanotubes (CNTs): in some reports CNTs have been used for gene delivery without significant toxicity, whilst in others various cytotoxic effects were observed, including induction of intracellular reactive oxygen species (ROS), DNA damage and apoptosis. Whilst it is clear that CNTs production method, purity and functionalization treatments impact on biocompatibility, most of the published reports lacked of detailed characterization of the CNT samples used. We investigated the effect of various physical-chemical features of multi-walled carbon nanotubes (MWCNTs) on toxicity and biocompatibility with cultured human neuroblastoma cells by using MTT, WST-1, Hoechst and oxidative stress assays. In-vitro experiments confirm that after 3-days incubation with 3 different types of CNTs dispersed in pluronic solution (PF-127) 0.01% cell viability is not affected and apoptosis and ROS are not induced in the SH-SY5Y cells. With prolonged cultures and continued propagation in presence of MWCNTs, the loss of cell viability was minimal for pure MWCNTs (99% purity) but cell proliferation decreased significantly for 97% purity MWCNTs and acid treated MWCNTs (97% purity, surface oxidation 8%); no intracellular ROS was detected. When the concentration of nanotubes increases, purity and surface oxidation seem to affect sensibly cell viability (ED25 is 48, 34.4 and 18.4 mug/ml respectively for 99% purity MWCNTs, 97% purity MWCNTs and acid treated 97% purity MWCNTs). In conclusion, our results indicate that concentrations of 5-10 mug/ml MWCNTs seem ideal for studies on the design and development of artificial MWCNT nano-vectors for gene and drug therapy against cancer.
PMID: 19341817 [PubMed - as supplied by publisher]