中文摘要：

目的制备水溶性好和细胞毒性低的多壁碳纳米管一聚乙烯亚胺（MWCNTs-PEI）复合物，为进一步开展碳纳米管载带药物的研究奠定一定基础。方法通过聚乙烯亚胺（PEI）共价修饰羧基化多壁碳纳米管（MWCNTs—COOH），制备了多壁碳纳米管一聚乙烯亚胺复合物，利用透射电镜、红外光谱、紫外光谱和热重分析等手段对其进行表征，并采用四甲基偶氮噻唑蓝法（MTT）测定了多壁碳纳米管．聚乙烯亚胺复合物对PCI2细胞的毒性大小，初步评价了其生物相容性。结果多壁碳纳米管一聚乙烯亚胺复合物的溶解度为1．009mg·mL-1，羧基化多壁碳纳米管复合物的溶解度为0．0601mg·mL-1，多壁碳纳米管-聚乙烯亚胺复合物溶解度是羧基化多壁碳纳米管溶解度的16倍左右；通过四甲基偶氮噻唑蓝法测得多壁碳纳米管-聚乙烯亚胺复合物对PCI2细胞的毒性明显小于羧基化多壁碳纳米管，且两者之间存在统计学意义上的显著性差异（P〈0．05）。结论多壁碳纳米管-聚乙烯亚胺复合物不仅改善了碳纳米管的分散性，而且还降低了碳纳米管的细胞毒性。

英文摘要：

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 polyeth- ylene（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 com- plexes were respectively 1. 009 and 0. 060 1 mg· mL-1 , and the former was about 16 times of the latter. The cytotoxicity of MWCNTs-PEI composite on PC12 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.