新型前哨淋巴结示踪剂的制备及动物实验研究

The preparation and experimental study of a new sentinel lymph node tracer

背景与目的:前哨淋巴结活检是临床腋窝淋巴结阴性早期乳腺癌患者治疗的标准。准确定位前哨淋巴结对分期、预后及治疗至关重要。该研究将利妥昔单抗与荧光示踪剂吲哚菁绿偶联,制备新型前哨淋巴结示踪剂,确定最佳偶联比例,并对其生物学特性、安全限度及定位性能进行研究。方法:直接偶联法制备新型前哨淋巴结吲哚菁绿-利妥昔单抗,双层析快速薄层层析-硅胶层析纸法测定标记率,非还原型SDS聚丙烯酰胺凝胶电泳法和双抗体夹心间接酶联免疫测定法检测新型示踪剂中单抗分子完整性和免疫活性,按中华药典要求检测新型示踪剂的安全限度及在小鼠体内前哨淋巴结的定位性能。结果:新型示踪剂中利妥昔单抗分子完整且保持了单抗的免疫活性,利妥昔单抗大分子上吲哚菁绿的标记率为100%,新型示踪剂为无菌、无致热原的溶液且局部注射不会产生危害。利妥昔单抗与吲哚菁绿质量比例为4∶1、6∶1偶联形成的新型示踪剂,前哨淋巴结显像效果最佳。前哨淋巴结定位与核素法一致。结论:吲哚菁绿-利妥昔单抗偶联的新型前哨淋巴结示踪剂的制备工艺简单且无放射性危害,其中单抗的分子完整性和免疫活性无破坏,为无菌、无致热原、无急性毒性的示踪剂,能够用于前哨淋巴结显像。

Background and purpose： Sentinel lymph node biopsy is regarded as the standard of care in patients without clinical axillary lymph node metastases in early-stage breast cancer. Accurate detection of sentinel lymph node is an important step for staging, prognosis, and treatment. In this study, a new sentinel lymph node tracer was produced by the rituximab to combine with the fluorescence tracer （indocyanine green, ICG）, and to identify the most appropriate combination ratio of the two agents. Its biological property and safety limitation were evaluated. Methods： Rituximab was combined directly with ICG. The new tracer was analyzed for labeled rate by instant thin-layer chromatography-silica gel, molecular integrity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and molecular immune activity by ELLAS. The safety limitation was tested according to the Chinese Pharmacopeia. The localization ability of sentinel lymph node was tested in mice. Results： The new tracer was intact and kept the immune activity of rituximab. The ICG labeled rate of rituximab was 100%. The new tracer was bacteria and pyogen free, and was safe to body with location injection. The most appropriate combination ratio of rituximab and ICG was 4 ： 1 and 6 ： 1 with the best sentinel lymph node imaging. The location of sentinel lymph node identified by the new tracer was accorded with the radiotracer. Conclusion： The preparation method of the new sentinel lymph node tracer is simple and no radioactive injury. The new tracer has no bacteria, no pyogen and no acute toxicity, and can be used in sentinel lymph node visualization.