【作者】 周斯博；

【导师】 骆清铭；

【作者基本信息】 华中科技大学 ， 生物医学工程， 2005， 硕士

【摘要】 肿瘤治疗作为医学研究的热点,长期以来得到了广泛和深入的研究。在众多的肿瘤治疗方法中,光动力疗法(PDT)得到了越来越多的关注。肿瘤细胞的生存和生长主要依靠肿瘤周围血管提供营养成分,PDT 的肿瘤治疗机制之一就是能够破坏肿瘤周围血管并抑制新血管的生成,从而达到治疗肿瘤的效果。然而,PDT 的这种血管损伤效应的机制,目前并未被完全研究清楚,原因在于动物模型的限制和成像方法的局限。本文分别针对研究PDT过程中上述两方面的局限性,提出了使用稳定高表达GFP的单克隆细胞株ACC-M-GFP 细胞悬液在无壳鸡胚尿囊膜(CAM)上建立肿瘤模型,运用荧光光学成像技术以示踪肿瘤细胞的生长位置来研究肿瘤生长。实验中,对已建立的CAM 肿瘤模型上的肿瘤及其周围血管进行光动力治疗,并利用激光散斑成像技术实时观测肿瘤周围血管的变化情况,如管径、流速等,并由以上数据获得血管的灌流量,由此评估血管的损伤程度。结果表明:1)在鸡胚上种植异体肿瘤的方法简便易行,是研究PDT 诱导血管损伤、肿瘤悬浮细胞生长和新血管生成的一个理想模型,还可以用来评估血管生成因子的活性; 2)利用激光散斑成像技术评估PDT 作用的血管损伤,不仅可以测量血管的管径变化,并可以测量血液流速或灌注率的变化,这为研究PDT 对血管的损伤作用机制提供新的血液动力学研究方法。综上所述,本文的研究结果表明,CAM 肿瘤模型为研究PDT 的血管损伤效应提供了良好的动物模型基础。结合荧光成像技术,CAM 能够精确地对肿瘤生长区域进行定位,能够监测肿瘤生长; 由于光敏剂的特性,CAM 上的激光照射区域可被准确地确定。利用激光散斑成像技术获得PDT 光照射区域内的血液灌注量的变化信息,对于实时在体监测PDT 引起的血管损伤效应有重要帮助。该研究结果对于研究新型光敏剂、寻找肿瘤治疗的最佳光动力剂量具有重要意义。更多还原

【Abstract】 The tumor treatment has long been an important research issue. Compared with many other approaches, the photodynamic therapy (PDT) attracts more research attentions in recent years. Since the growth of tumor cell relies on the surrounding vessels to provide nutrition, while one of the key effects of PDT in tumor treatment is its effect of vascular damage, PDT has become the research focus by many researchers. However, one limitation is that the mechanism behind destroying the vessels and prohibiting the neovascularization is not clear so far. This limitation is partly due to the unsuitableness of current animal models and the unsatisfactory performance of existing imaging methods. Aimed at these two limitations during PDT research, based on the ACC-M-GFP cell suspensions with stable and highly expressible GFP on shell-less chorioallantoic membrane (CAM), the tumor model is built and its growth and location are observed by using fluorescence imaging technique. In this study, by using the CAM tumor model, the PDT is applied on the tumor and the surrounding vessels, together with the laser speckle contrast imaging (LSCI) to real-time monitor the variance of the vessels during PDT, such as vessel diameter, blood velocity, etc. The vessel perfusion can then be calculated, and the degree of vessel damage is also evaluated. The results prove: 1) It’s very convenience to transplant human tumor on chicken embryo. Such operation is suitable for the study of the vascular damage induced by PDT and the growth and neovascularization of tumor cell suspensions. In addition, the operation can also be used to evaluate the angiogenic activity. 2) It’s suitableness to use LSCI technique to evaluate the vessel damage because it can not only measure the vessel diameter change, but also can estimate the blood velocity change and perfusion change. Such capability of LSCI technique provides a new hemodynamic method for the research of PDT effect on vessel. Our research demonstrates that the CAM tumor model is an excellent model to examine the vascular damage effect of PDT. With the aids of fluorescent imaging technique, the CAM can locate the tumor region more precisely so that the growth of tumor could be monitored. In addition, due to the characteristic of photosensitizer, the irradiation region on CAM can also be identified. Using LSCI to obtain the blood perfusion change in PDT irradiation region enables real-time monitoring of the vascular damage effect by PDT, which has obvious the significance in developing new photosensitizer and discovering better photodynamic dosage for tumor treatment.更多还原