title: The functionalization of multi-walled carbon nanotubes by in situ deposition of hydroxyapatite.
abstract: A simple and effective approach was introduced to functionalize multi-walled carbon nanotubes (MWNTs) by in situ deposition of hydroxyapatite (HA) to improve their hydrophilicity and biocompatibility. Firstly, we prepared two types of pre-functionalized MWNTs: acid-oxidated MWNTs and covalently modified MWNTs by poly (ethylene glycol) (PEG). The influences of the acid-oxidated time, pre-phosphorylation, and PEGylation of MWNTs on in situ growth of HA were further investigated in simulated body fluid (SBF) with ionic concentration: 2, 5 and 10 times, respectively, at 37 degrees C for 24h. The results exhibited that all these factors have positive effects on the HA crystals growth, especially the PEGylation of MWNTs plays a key role during the deposition. Finally, the methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate their cytotoxicity, which showed that the PEGylated MWNTs wrapped by HA crystals have the best biocompatibility.
authors.affiliation: School of Materials Science and Engineering, Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, Sichuan, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xiao
authors.forename: Tao
authors.initials: T
authors.lastname: Gong
authors.forename: Shaobing
authors.initials: S
authors.lastname: Zhou
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage* / Q000737:chemistry*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017886:Durapatite / Q000008:administration & dosage* / Q000737:chemistry*; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects*; D051381:Rats
chemical_list: D001672:Biocompatible Materials; D037742:Nanotubes, Carbon; D017886:Durapatite