Interaction of nanoparticles with cellular compartments and proteins

将合成和表征包含荧光标记的尺寸、聚合物类型和表面官能度相关参数的多组聚合物纳米颗粒。利用先进的荧光显微镜技术，我们将详细探索细胞摄取机制及其对纳米粒子的物理性质(大小、形状)和表面化学(化学功能、电荷和极性)的依赖。我们将详细分析纳米颗粒是如何在细胞内处理的(运输机制、与细胞器的结合、降解)，以及细胞对纳米颗粒掺入的反应。这些研究将使用由Mailänder/Simmet小组提供的培养细胞的时间分辨旋转圆盘共聚焦显微镜，并辅之以对活细胞进行4PI共聚焦实验和具有超高空间分辨率的STED显微镜。通过这些实验，我们的目标是实现对培养细胞对纳米颗粒的反应的分子方面的机械描述，这是了解纳米颗粒对整个生物体的影响的第一个重要步骤。吞噬单核细胞是炎症和宿主防御的关键。因此，它们配备了结合蛋白和受体，使纳米颗粒能够有效地感应和内化。在这种背景下，不仅要深入了解设计独特的纳米颗粒与分化的原代细胞和去分化的肿瘤细胞之间的相互作用，而且要确定可能的受体和靶分子，开发描述纳米颗粒和细胞之间相互作用的数学模型，以及确定纳米颗粒可能靶向的细胞功能。

Sets of polymeric nanoparticles of defined parameters concerning size, type of polymer and surface functionality containing a fluorescent marker will be synthesized and characterized. With advanced fluorescence microscopy techniques, we will explore in detail the uptake mechanisms by the cell and their dependencies on the physical properties of the nanoparticle (size, shape) and its surface chemistry (chemical functions, charge and polarity). We will analyze in detail how nanoparticles are processed within the cell (transport mechanisms, association with organelles, degradation), and responses of the cell to nanoparticle incorporation. These studies will be done by using time-resolved spinning disk confocal microscopy on cultured cells provided by the Mailänder/Simmet groups, complemented by 4Pi-confocal experiments and STED microscopy with ultra-high spatial resolution on living cells. With these experiments, we aim to achieve a mechanistic description, in molecular terms, of the response of cultured cells to nanoparticles, which is a first important step towards an understanding of the effects of nanoparticles on the entire organism. Phagocytosing monocytic cells are pivotal for inflammation and host defence. Accordingly, they are equipped with binding proteins and receptors that allow efficient sensing and internalization of nanoparticles. On this background it is very important to gain insight not only in i) the interaction between distinctly designed nanoparticles with differentiated primary cells and dedifferentiates tumor cells, but also ii) to identify possible receptors and target molecules, iii) to develop mathematical models describing the interaction between nanoparticles and the cells, and iv) to identify cell functions that may be targeted by nanoparticles.