体外评价羧甲基壳聚糖超顺磁氧化铁纳米粒的细胞毒性和巨噬细胞的摄取

The in vitro evaluation on O-carboxymethyl chitosan superparamagnetic iron oxide nanoparticles

目的体外评价自制羧甲基壳聚糖超顺磁氧化铁纳米粒(OCMCS-SPIO-NPs)的细胞毒性和逃避巨噬细胞的吞噬能力。方法以菲立磁和未包被的超顺磁氧化铁纳米粒为对照,采用四唑盐(MTT)比色法考察OCMCS-SPIO-NPs对LO2细胞(正常肝细胞株)和A549(人肺腺癌细胞株)的细胞毒性;用菲洛嗪法及普鲁士蓝法考察OCMCS-SPIO-NPs纳米粒并评价其体外的抗吞噬能力。结果 SPIO-NPs经羧甲基壳聚糖共价修饰后,对LO2和A549细胞的细胞毒性明显降低,OCMCS-SPIO-NPs的细胞毒性和dextran-SPIO的细胞毒性无显著性差异(P>0.05),其细胞毒性与培养基中SPIO的浓度呈正相关;与3种SPIO纳米粒孵化24h后,RAW264.7细胞内铁含量随培养基中SPIO的含量增加而增加,细胞内铁含量依次为:未包被SPIO-NPs>dextran-SPIO-NPs>CMCS-SPIO-NPs组(P<0.05)。结论超顺氧化铁纳米粒经羧甲基壳聚糖共价修饰后能显著降低细胞毒性和吞噬细胞摄取,提高了生物相容性,显著降低了巨噬细胞对其的摄取。

OBJECTIVE To investigate cell cytotoxicity and the ability to evade the capture by macrophage of O-carboxymethyl chitosan superparamagnetic iron oxide nanoparticles by comparing with Ferumoxides（dextran-SPIO-NPs）and uncoated SPIO-NPs.METHODS Tetrazolium salt（MTT） assay was used to evaluate cell cytotoxicity of the three SPIO-NPs against LO2（normal liver cells）and A549（human lung adenocarcinoma cells）.After being incubated with dextran-SPIO-NPs,uncoated-SPIO-NPs or OCMCS-SPIO-NPs respectively,the intracellular iron content in mouse macrophage（RAW 264.7）was visualized by Prussian blue staining,and quantified by Ferrozine assay.RESULTS The cytotoxicity of both OCMCS-SPIO-NPs and dextran-SPIO-NPs were significantly lower than that of uncoated-SPIO-NPs（P 0.01）,while there was no significant differencce between the cytotoxitcity of OCMCS-SPIO-NPs and dextran-SPIO-NPs（P 0.05）,The intracellular iron content results indicated that there was a dose dependent increase in intracellular iron content in RAW264.7 cell.Both the Ferrozine assay and Prussian blue staining showed that there was a significant difference among the three groups in intracellular iron content in RAW264.7 cell incubated with OCMCS SPIO-NPs,dextran-SPIO-NPs or uncoated-SPIO-NPs for 24 h.The result was as follows：Uncoated-SPIO-NPs Ferumoxides OCMCS-SPIO-NPs（P 0.05）.CONCLUSION The surface modification with O-carboxymethyl chitosan can sharply reduce the cell cytotoxicity of superparamagnetic iron oxide nanoparticles and macrophages cellular uptake.The OCMCS SPIO-NPs had low cytotoxicity,good biocompatibility and low macrophage cellular uptake.