title: Hydroxylation of multi-walled carbon nanotubes reduces their cytotoxicity by limiting the activation of mitochondrial mediated apoptotic pathway.
abstract: Hydroxylation of carbon nanotubes (CNTs) can enhance their dispersibility in water, and allows the capability to conjugate with other molecules for the expected applications. However, the cytotoxicity of hydroxylated CNTs has not been thoroughly investigated. Here, we compared the cytotoxicity of hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) on a human cell line with that of pristine multi-walled carbon nanotubes (p-MWCNTs). We showed that while both MWCNTs-OH and p-MWCNTs induced apoptosis in a time- and dose-dependent manner, MWCNTs-OH triggered a significantly milder cytotoxic response than that of p-MWCNTs. We further showed that such attenuated response could be attributed to a reduced disruption of the mitochondrial membrane potential (MMP), leading to the attenuation of both cytochrome c (cyt-c) release and activation of caspases. These findings suggest that MWCNTs-OH, could be more biocompatible for in vivo applications than that of p-MWCNTs by limiting the activation of the mitochondrial mediated apoptotic pathway.
authors.affiliation: School of Pharmaceutical Sciences, Central South University, Changsha, 410013, Hunan, People's Republic of China.
authors.forename: Zhenbao
authors.initials: Z
authors.lastname: Liu
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Liu
authors.forename: Dongming
authors.initials: D
authors.lastname: Peng
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D001672:Biocompatible Materials / Q000737:chemistry* / Q000633:toxicity*; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006900:Hydroxylation; D008422:Materials Testing; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects / Q000502:physiology; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000633:toxicity* / Q000648:ultrastructure; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D001672:Biocompatible Materials; D037742:Nanotubes, Carbon; D045304:Cytochromes c; C505407:CASP3 protein, human; C505520:CASP7 protein, human; D053148:Caspase 3; D053179:Caspase 7