We prepared the superparamagnetic chitosan nanoparticles (SPCIONPs) to study the application of them as gene vectors using a magnetic transfection system for the targeted treatment of lung metastasis of osteosarcoma. The SPCIONPs were characterized by transmission electron microscopy, Fourier transform infrared spectrometry, superconducting quantum interference device and atomic force microscopy. Their biosafety was determined by cell counting kit-8 (CCK8) and live–dead staining assays. The transfection in vitro was detected by laser confocal microscopy. SPCIONPs, which can bind closely to plasmids and protect them from DNA enzyme degradation, were prepared with an average particle size of approximately 22 nm and zeta potential of 11.3 mV. The results of the CCK8 and live–dead staining assays showed that superparamagnetic chitosan nanoparticles loaded with insulin-like growth factor-binding protein 5 (SPCIONPs/pIGFBP₅) induced no significant cytotoxicity compared to the control group. The result of transfection in vitro suggested that pIGFBP₅ emitted a greater amount of red fluorescence in the SPCIONPs/pIGFBP₅ group than that in the chitosan-loaded IGFBP₅ (CS/pIGFBP₅) group. In conclusion, the prepared SPCIONPs had good biosafety and could be effectively used to transfer pIGFBP₅ into 143B cells, and they thus have good application prospects for the treatment of lung metastasis of osteosarcoma.

我们制备了超顺磁性壳聚糖纳米颗粒（SPCIONPs），以研究其作为基因载体的应用，使用磁转染系统靶向治疗骨肉瘤的肺转移。通过透射电子显微镜，傅立叶变换红外光谱，超导量子干涉仪和原子力显微镜对SPCIONP进行了表征。通过细胞计数试剂盒8（CCK8）和活死染色测定法确定了它们的生物安全性。体外转染通过激光共聚焦显微镜检测。可以与质粒紧密结合并保护其免受DNA酶降解的SPCIONP，其平均粒径约为22 nm，ζ电位为11.3 mV。CCK8和活死染色分析的结果表明，与对照组相比，负载了胰岛素样生长因子结合蛋白5（SPCIONPs / pIGFBP ₅）的超顺磁性壳聚糖纳米颗粒没有引起明显的细胞毒性。体外转染的结果表明，与负载壳聚糖的IGFBP ₅（CS / pIGFBP _5）相比，SPCIONPs / pIGFBP ₅组中pIGFBP ₅发射出更多的红色荧光。）组。综上所述，所制备的SPCIONPs具有良好的生物安全性，可以有效地将pIGFBP ₅转移至143B细胞中，因此具有治疗骨肉瘤肺转移的良好应用前景。