Micropatterned Binary Nanoarrays as a Tool to Determine the Spatial Requirement of Heterotypic Integrin Clusters

整合素是一种跨膜受体，与细胞外基质(ECM)蛋白结合，感知和调节细胞外环境的物理性质，进而调节细胞的时空命运。尽管新的技术和分析工具极大地提高了我们对整合素功能的理解，但对来自特定整合素的细胞活性或不同整合素之间的合作的研究仍然具有挑战性。在这个方案中，我们首先选择性和定量地剖析了两个基本的纤维连接蛋白结合整合素的单独功能，α5β1和αvβ3。为了实现这一点，我们将常规地使用六方排列的金纳米阵列作为模板来控制固定化的整合素选择性多肽类药物的密度。此外，我们将对金纳米阵列进行微图案化，以限制细胞的形状，以便利用相衬和荧光显微镜可靠地研究扩散、收缩和迁移。最后，我们将设计微图案化的金-二氧化钛二元纳米阵列，能够在指定的密度下模板两种不同的整合素结合配体。利用这些底物，我们的目标是通过同时定量地参与α5β1和αvβ3来定制细胞反应，以表征整合素串扰的相加或协同性质。

Integrins are transmembrane receptors that bind to extracellular matrix (ECM) proteins, and sense and modulate the physical properties of the extracellular environment, which in turn regulates spatio-temporally the fate of cells. Although new technologies and analytical tools tremendously improved our understandings of integrin functions, the investigation of cell activity derived from a particular integrin or the cooperation between different integrins remains challenging. In this proposal, we first focus on dissecting selectively and quantitatively individual functions of two essential fibronectin-binding integrins, α5β1 and αvβ3. To achieve this, we will routinely use hexagonally organized gold nanoarrays as a template to control the density of immobilized integrin-selective peptidomimetics. Additionally, we will micropattern gold nanoarrays to confine the shape of cells in order to reliably study spreading, contractility and migration with phase contrast and fluorescent microscopy. Finally, we will design micropatterned gold – titanium dioxide binary nanoarrays able to template two different integrin-binding ligands at defined densities. With the mean of such substrates, we aim at tailoring the cell response by engaging simultaneously and quantitatively α5β1 and αvβ3 to characterize the additive or synergistic nature of the integrin crosstalk.