Basic study for sonodynamic therapy to the experimental brain tumor.

我们证实了声动力疗法对实验性脑肿瘤--Wister大鼠脑内种植的大鼠C6胶质瘤的疗效。用电子显微镜观察其对脑肿瘤的影响及对周围正常脑组织血脑屏障的影响。EM检查显示内皮细胞胞浆肿胀、大量吞噬、胞膜中断，提示聚焦超声声动力学治疗可破坏瘤周脑组织的血脑屏障。本实验采用对声动力治疗敏感性不同的人脑胶质瘤细胞U251和U105。U251胶质瘤细胞在裸鼠脑内移植并存活，但没有生长到肿瘤肿块。这些细胞的增殖情况因动物不同而不同。U105胶质瘤细胞既不能在裸鼠脑内存活，也不能生长到块状，不能作为实验性脑肿瘤模型。我们用U87人脑胶质瘤细胞进行裸鼠实验性脑肿瘤的实验研究。将这些细胞成功植入裸鼠脑内，在一周内生长到肿块，利用聚焦超声对U87人脑胶质瘤细胞进行声动力学治疗。裸鼠暴露于脑内，消毒后用聚焦超声照射，但损伤部位极易感染，易出现脑膜炎或脑脓肿。我们正在摸索解决这些问题。

We confirmed efficacy of sonodynamic therapy to the experimental brain tumor, rat C6 glioma which was implanted in Wister rat brain. We evaluated how to effect to the brain tumor and how to effect to the blood brain barrier of the surrounding normal brain tissue using the electron microscope (EM). EM study demonstrated swelling of the cytoplasm, plenty of pinocytosis and interruption of the cytoplasmic membrane in the endothelial cells, suggesting destruction of the blood brain barrier of the peritumoral brain tissue by the sonodynamic therapy using the focused ultrasound. In this experiment, human glioma cells, U251 and U105, which were different in sensitivity to sonodynamic therapy, were used. U251 glioma cells were implanted and survived in the nude rat brain but didn't grow up to neoplastic mass. These cells differed in proliferation depending upon each animal. U 105 glioma cells neither survived in the nude rat brain nor grew up to the mass, so these glioma cells couldnt be used as experimental brain tumor model. We used U87 human glioma cells for experimental brain tumor in the nude rat. These cells were implanted into the nude rat brain successfully and grew up to the mass in a week, so U87 human glioma cells were used for sonodynamic therapy by the focused ultrasound. The nude rat brain was exposed and was irradiated by the focused ultrasound after disinfection, however the lesion was suffered from infection very easily and tended to have meningitis or brain abscess. We are groping to resolve these problems.