ABSTRACT
OBJECTIVE: To synthesize water-soluble multi-walled carbon nanotubes-polyethyleneimine (MWCNTs-PEI) composite with low cytotoxicity and to lay a foundation for further research of loading drugs with carbon nanotubes. METHODS: MWCNTs-PEI composite was prepared by modifying carboxylated multi-walled carbon nanotubes(MWCNTs-COOH) with polyethylene (PEI), and then the composite was characterized by transmission electron microscopy, infrared spectra, UV spectra and thermalgravimetric analysis. The cytotoxicity of the composite on PC12 cells was measured by methyl thiazolyl tetrazolium(MTT) assay to preliminarily evaluate its biocompatibility. RESULTS: The dissolubilities of MWCNTs-PEI and MWCNTs-COOH complexes were respectively 1.009 and 0.0601 mg · mL-1, and the former was about 16 times of the latter. The cytotoxicity of MWCNTs-PEI composite on PC 12 cells was significantly milder than that of MWCNTs-COOH composite as indicated by MTT assay (P < 0.05). CONCLUSION: MWCNTs-PEI composite not only improves the dispersibility of carbon nanotubes, but also reduces its in vitro cell toxicity.