^32P-磷酸铬-聚L乳酸粒子植入肝癌H22移植瘤模型治疗淋巴道转移的潜能

Therapeutic potential of lymph metastasis after ^32P-chromicphosphate-poly L-lactic acid seeds implanted into hepatoma H22 xenograft model

目的 观察^32P-磷酸铬-聚L乳酸（^32P-CP-PILA）粒子瘤体植入后对KM小鼠肝癌H22淋巴转移模型区域淋巴结（LN）治疗的潜能.方法 KM小鼠55只,建立右爪垫移植瘤淋巴道转移模型,随机分11组（n=5）.移植瘤体分别植入^32P-CP-PLLA粒子或注射胶体^32P-磷酸铬（^32P-CP）,剂量依序为18.5、37.0、74.0 MBq;另剂量为37 MBq/只,植瘤后于3、7、10、13 d不同时间植入^32P-CP-PLLA 粒子.给药后动态γ显像,14 d处死,解剖KM小鼠,剥离引流区右腘窝淋巴结（PLA）和腹股沟淋巴结（ILN）,电子天平称取质量,对瘤体和LN进行光镜、电镜检测,观察量效关系和时效关系.结果 γ显像证实移植瘤体^32P-CP-PLLA粒子组较胶体^32P-CP组局限浓聚且持久,放射性粒子无移位或脱落.区域LN聚集的放射性随给药剂量增加而增大,质量则反之;同剂量LN活度胶体组明显高于粒子组.同等剂量下,PLN的质量胶体组与粒子组差异无统计学意义（P＞0.05）;ILN的质量胶体组小于粒子组（P＜0.05）.不同时间植入粒子,各组PLN质量差异有统计学意义（F=31.268,P＜0.01）.结论 ^32P-CP-PLLA粒子植入瘤内靶向定位性好,在治疗移植瘤的同时对淋巴道转移有一定的治疗作用.

Objective To compare the therapeutic potential of ^32P-chromicphosphate-poly L-lactic acid （^32P-CP-PLLA） seeds on regional lymph nodes in the KM mice model of hepatoma H22 lymph metastasis after intratumoral implantation. Methods Ascitic hepatoma cells （H22） were injected into right fat pad to establish lymph metastasis model in KM mice. Fifty-five KM mouse models were randomly divided into different groups （n=5 each） through ^32P-CP-PLLA implantion or colloid ^32 P-chromicphosphate （ ^32P-CP） intravenous injection. Different doses at 18. 5, 37. 0 or 74. 0 MBq per mouse were used immediately after establishing the tumor models. Different injection time points of 3, 7, 10 or 13 days were used as well at the dose of 37 MBq per mouse. Dynamic imaging was performed by γ camera. Thereafter, all of KM mice were sacririced to separate popliteal lymph node （PLN） and inguinal lymph nodes （ILN）. The dose- and time-effect relation was observed by lymph node weight, light microscopy and electron microscopy. Results γ camera imaging demonstrated that the implantation points in ^32P-CP-PLLA group had a limited and lasting radioactive uptake while the quality was the contrary, better than that in ^32P-CP group. At the same dose the colloidal group had a higher radioactivity than the seed group. At the same dose, the PLN quality of seed group and colloidal group was not significantly different （ P 〉 0. 05 ） ; The ILN quality of colloidal group is less than seed group （P 〈 0.05 ）. Seeds implanted at different times, PLN quality is significantly different （ F=31. 268 ,P 〈0. 01 ）. Conclusion ^32P-CP-PLLA seeds implanted into tumor targeting position is better than ^32P-CP. There is a therapeutic effect to the lymph node metastasis as well as the treatment of tumor.