【作者】 吴丽媛；

【导师】 施维； 牟颖；

【作者基本信息】 吉林大学 ， 生物化学与分子生物学， 2011， 硕士

【摘要】 癌症的诊断迄今所依赖的主要是一些离体检测方法以及超声波、X射线透视、X射线CT、核磁共振成像等影像学技术。癌症的确诊则以肿瘤组织或病变细胞的形态和其它宏观特征为依据,是一个侵入性和很耗时的过程,不利于癌症的早期诊断,而且上述各种影像学技术目前也难以在分子水平上发现问题。然而光学成像方法,特别是荧光成像方法具有对人体无害、非侵入、高灵敏和可进行在体成像等优点,有望在分子和细胞水平上实现癌症的早期诊断。聚合物囊泡是近几年才刚刚发展起来的一种软纳米材料,由于其独特的化学组成和结构,赋予其许多十分优越的理化性质,这些性质决定了纳米尺寸的荧光聚合物囊泡很可能发展成为极具前途的一种荧光标记探针。本研究工作的重点即是制备基于这种软纳米材料的聚合物囊泡靶向荧光探针,并利用其对肺癌细胞A549进行靶向标记。首先,对聚合物囊泡近年来的发展进行了综述,介绍了聚合物囊泡的组成、结构、表征手段、合成与物质装载方法以及聚合物囊泡作为荧光探针的应用。其次,利用两亲性嵌段共聚物PBD-b-PEO与脂溶性荧光染料尼罗红通过膜相再水合的方法,自组装成荧光聚合物囊泡。再经过超声、冻融、挤压等一系列处理过程来控制聚合物囊泡粒径的大小,使其便于在生物学上的应用。再次,采用端羟基活化和生物素-亲和素系统结合的方法对聚合物囊泡进行表面功能化修饰,使其构成一种通用的靶向平台。最后,利用制备的具有靶向性的荧光聚合物囊泡作为生物荧光探针,对肺癌细胞A549进行初步标记。总之,本研究工作以嵌段共聚物PBD-b-PEO与脂溶性荧光染料尼罗红自组装成荧光聚合物囊泡,通过表面功能化修饰和控制粒径大小,使其构成通用的靶向平台。通过连接特异性的抗体,可以实现对癌症细胞的靶向荧光标记,有望成为一种新型荧光标记探针。更多还原

【Abstract】 Up-to-now, the cancer diagnosis depends mainly on in vitro detection procedures and such imaping techniques as ultrasonic imaging, X-ray photography, X-ray computed tomography, nuclear magnetic resonance imaging, etc. The determination and confirmation of cancers are relying on the morphology and other macroscopic characteristics of tumor tissues or ill cells, and this is usually an invasive and time-consuming process. Such procedure is definitely not suitable for early cancer diagnostics. Aforementioned imaging techniques are difficult to find the symptom of cancers at molecular level. Nevertheless, optical imaging technologies, especially fluorescence molecular imaging, possess advantages of harmlessness, noninvasiveness, super sensitivity and possibility for in vivo imaging and are believed to have the possibility to realize the diagnosis of cancers at molecular and cell levels.Polymersomes newly emerging for the past few years are kinds of self-assembly soft nano materials. Due to their unique chemical composition and construction, they have many predominant physico-chemical properties which make them very promising fluorescent probes. Our work put emphasis on preparation of fluorescent probe based on polymersomes and target lung cancer cell A549 with polymersomes. First, we summarize the development of polymersomes for the past few years, including the composition and construction of polymersomes, characterizing manner, methods of preparation and materiel loading and application of polymersomes as fluorescent probes. Second, we investigate the method of rehydration preparing polymersomes with amphiphilic block copolymer and nile red. With a series of treatments of sonication, freeze-thaw and extrusion, we could control the size distribution of polymersomes effectively in order to facilitate utilization in biology. Third, we adopt the strategy of end terminal hydroxide activation and biotin-avidin system to functionalize the surface of polymersomes, which make them generic nanoplatform. Last, we labeled lung cancer cell A549 with targeting fluorescence-emissive polymersomes as fluorescent probes and undertake the preliminary investigation of absorptive kinetics of polymersomes-cell interaction.In a word, we prepared polymersomes with amphiphilic block copolymer and nile red, then functionalize the surface of polymersomes, and complete a generic nanoplatform finally. With linkage of specific antibody, polymersomes could label lung cancer cell effectively and are believed to be new fluorescent probes.更多还原