目的：制备一种叶酸-磁双靶、载阿霉素(ADM)相变型脂质体纳米粒(FA-PFH-Fe₃O₄@ADM)，观察其对视网膜母细胞瘤Y79细胞的寻靶能力及体外超声/光声/磁共振三模态成像能力。

方法：采用双乳化法制备FA-PFH-Fe₃O₄@ADM纳米粒，检测其基本特性及细胞安全性，观察纳米粒在808nm激光下的升温现象及相变情况。将对数生长期的Y79细胞进行分组，非靶向组及单磁靶组加入PFH-Fe₃O₄@ADM纳米粒(0.625mg/mL)，单叶酸靶组及叶酸-磁双靶组加入FA-PFH-Fe₃O₄@ADM纳米粒(0.625mg/mL)，并于单磁靶组和叶酸-磁双靶组的孔板侧放约4T磁铁1枚，评估纳米粒对Y79细胞的寻靶能力。此外，观察FA-PFH-Fe₃O₄@ADM纳米粒体外超声/光声/磁共振三模态成像能力。

结果：成功制备的FA-PFH-Fe₃O₄@ADM纳米粒呈分布均匀、大小均一的球形结构，平均粒径为338.6±2.20nm，成功装载ADM和Fe₃O₄，包封率分别为(41.76±4.12)%、(59.06±13.63)%，具有良好的顺磁性能，且对Y79细胞无明显的生物毒性。叶酸-磁双靶组吞噬率[(86.19±0.55)%]高于单叶酸靶[(43.36±5.91)%]和单磁靶组[(28.58±3.23)%](P<0.05)。激光作用下，FA-PFH-Fe₃O₄@ADM纳米粒能迅速升温并发生相变，且可以增强超声及光声成像，T₂模式下可对磁共振成像进行负性增强。

结论：本研究成功制备的FA-PFH-Fe₃O₄@ADM纳米粒不仅对视网膜母细胞瘤Y79细胞具有较好的靶向性，还能实现体外超声/光声/磁共振三模态成像。

METHODS: FA-PFH-Fe₃O₄@ADM was prepared by the double emulsification method, and its basic characteristics were tested. Test the cellular safety of nanoparticles. Observe the heating phenomenon and phase transition of nanoparticles under 808nm laser. Y79 cells in logarithmic growth phase were divided into four groups. The non-targeted group and the single magnetic target group were added with PFH-Fe₃O₄@ADM nanoparticles(0.625mg/mL). The single folic acid target group and folic acid-magnetic dual target group were added with FA-PFH-Fe₃O₄@ADM nanoparticles(0.625mg/mL). A 4T magnet was placed at the side of the orifice plate of the single magnetic target group and the folic acid-magnetic double target group to evaluate the targeting ability of nanoparticles on Y79 cells. In addition, the ability of FA-PFH-Fe₃O₄@ADM nanoparticles ultrasound/photoacoustic/magnetic resonance three-mode imaging in vitro was observed.

RESULT: FA-PFH-Fe₃O₄@ADM nanoparticles were successfully prepared with uniform distribution and uniform spherical structure. The average particle size of nanoparticles was 338.6±2.20 nm. ADM and Fe₃O₄ were successfully loaded, with an encapsulation efficiency of(41.76±4.12)% and(59.06±13.63)%, respectively. Nanoparticles had good paramagnetic properties and showed no obvious toxicity to Y79 cells. The phagocytic rate of the folic acid-magnetic dual target group(86.19±0.55)% was significantly higher than that of the single folate target group(43.36±5.91)% and single magnetic target group [(28.58±3.23)%, P<0.05]. The FA-PFH-Fe₃O₄@ADM nanoparticles rapidly heat up and undergo phase transitions under the action of laser. Moreover, they can enhance ultrasound and photoacoustic imaging, and they can negatively enhance magnetic resonance imaging in T₂ mode.

CONCLUSION: FA-PFH-Fe₃O₄@ADM nanoparticles have been successfully prepared in this study, which not only has a good targeting effect on retinoblastoma Y79 cells, but also can achieve ultrasound/photoacoustic/magnetic resonance three-mode imaging in vitro.