Quantifying Carbohydrate Based Ligand/Rezeptor Interaction at Soft Hydrogel Interfaces via Soft Colloidal Probe AFM

通过软胶体探针AFM定量基于碳水化合物的配体/受体在软水凝胶界面的相互作用配体/受体（l/r）相互作用对于细胞生物学中的几乎所有过程都是至关重要的，包括信号转导、识别或免疫应答。生物医学应用中的材料设计也增加了配体官能化表面的使用，以实现期望的治疗效果。因此，对于生物医学材料的开发及其应用，必须对合成水凝胶界面处的l/r相互作用有一个基本的了解。例如，理论工作表明，柔软的、热波动的水凝胶界面可能导致协同结合事件。然而，这还没有在实验上证明。因此，本项目旨在开发一种新的基于力谱的方法，用于测定配体官能化软水凝胶颗粒和受体表面之间的结合能。该方法被称为“软胶体探针原子力显微镜”（AFM-SCP）。该方法开发的技术目标是大幅提高表面能测量的灵敏度，以便能够表征低亲和力l/r对。总体科学目标是调查软材料界面处的结合伙伴组装之间的合作结合事件。作为特定的生物分子结合物种，我们将研究基于碳水化合物的相互作用，因为它们最近已被证明具有高度的生物活性，但分子细节仍然没有得到很好的理解。我们将专注于作为l/r-材料基质（水凝胶）的材料参数的函数的结合协同性，即结合对的刚度、网格尺寸和密度。这些材料参数在生物分子相互作用中的影响迄今为止只是理论工作的问题，实验确认仍有待进行。因此，这些材料参数对低亲和力碳水化合物相互作用的影响将在本项目中通过AFM-SCP进行实验研究。

Quantifying Carbohydrate Based Ligand/Rezeptor Interaction at Soft Hydrogel Interfaces via Soft Colloidal Probe AFMLigand/receptor (l/r) interactions are crucial for almost all processes in cell biology, including signal transduction, recognition or immune response. Also material designs in biomedical applications make increased use of ligand functionalized surfaces to achieve a desired therapeutic effect. For biomedical material development and their application it is therefore imperative to achieve a fundamental understanding of l/r interactions at synthetic hydrogel interfaces. For example, theoretical work showed that soft, thermally fluctuating hydrogel interface may lead to cooperative binding events. However, this has not been experimentally shown yet. Therefore, this project aims at the development of a new force spectroscopy based method for the determination of binding energies between ligand functionalize soft hydrogel particles and receptor surfaces. The method is termed 'soft colloidal probe AFM' (AFM-SCP). The technical aim of the method development is to drastically enhance the sensitivity of the surface energy measurement in order to allow the characterization of low affinity l/r pairs. The overall scientific aim is the investigation of cooperative binding events between an assembly of binding partners presented at soft material interfaces. As specific biomolecular binding species we will study carbohydrate based interactions because they have been recently been show to be biologically highly active, however the molecular details are still not well understood. We will focus on the binding cooperativity as a function of the material parameters of the l/r- material matrix (hydrogel), i.e. stiffness, mesh size and density of binding pairs. The effect of these material parameters in biomolecular interactions was so far only a matter of theoretical work, experimental confirmations are still pending. Consequently, the effect of these material parameters on low affinity carbohydrate interactions will be experimentally studied via AFM-SCP in this project.