USPIO-PEG-sLeX 分子探针在裸鼠鼻咽癌移植瘤模型 MRI 的初步研究

目的：通过超顺磁性氧化铁(USPIO)螯合唾液酸化酶 X(sLeX )形成靶向内皮细胞黏附分子-1(ELAM-1)的特异性磁共振成像的分子探针(USPIO-PEG-sLeX ),并探讨其在鼻咽癌移植瘤的应用价值。方法利用物理沉积方法合成 USPIO 纳米颗粒,通过 PEG 修饰形成 USPIO-PEG-sLeX 。裸鼠鼻咽癌移植瘤模型分为实验组和对照组,分别经尾静脉注入 USPIO-PEG-sLeX 和USPIO-PEG 前后进行 MR T2 mapping 成像,比较分析注射对比剂前后移植瘤的 T2值变化。结果USPIO-PEG-sLeX 具有良好表征。对照组和实验组的鼻咽癌移植瘤的平扫 T2值差异无统计学意义(P >0.05),增强扫描后2组的 T2值下降,2组的 T2值差异有统计学意义(P <0.05)；实验组的强化率更低,2组的强化率差异有统计学意义(P <0.05)。实验组中瘤体与肌肉的强化率差异有统计学意义(P <0.05)。结论USPIO-PEG-sLeX 纳米磁性颗粒有望作为鼻咽癌 ELAM-1表达的靶向对比剂,在非创伤动态监测 ELAM-1的表达方面具有良好的潜在应用前景。

Magnetic resonance imaging of nude mice model injected in USPIO-PEG-sLeX in vivo

Objective To explore the value of the molecular probe USPIO-PEG-sLeX on nasopharyngeal carcinoma xenograft in nude mice.Methods The USPIO nanoparticles was synthesized by physical deposition method,and which was modified by PEG to synthesize USPIO-PEG-sLeX .The nude mice of nasopharyngeal carcinoma xenograft were divided into experimental and control groups.USPIO-PEG-sLeX and USPIO-PEG were injected into nude mice of experimental and control groups by caudal vein,respectively.MR T2 mapping imaging was scanned before and after the injection,and analyzed the changes of T2 values between experimental and control groups. Results USPIO-PEG-sLeX had a good representation.The non-enhanced T2 values between control and experimental group had no statistical significance (P >0.05).However,T2 values of the mice in two groups before and after injections were statistically significant (P <0.05);and T2 values of experimental group were much lower than that of the control group after the injection,additionally,the difference of enhanced rate between the two groups was statistically significant (P <0.05).Conclusion USPIO-PEG-sLeX magnetic nanoparticles is potential to be a targeted contrast agent to ELAM-1 expression of nasopharyngeal carcinoma,and can be valuable in non-invasive dynamic monitoring the expression of ELAM-1.