What's MEW in the UK? Engineering basement membranes using state-of-the-art biofabrication technologies

组织工程学通常使用旨在模拟生物组织结构的支架；然而，当前方法的规模和几何形状与自然界中发现的不同，这些差异阻碍了支架支持和控制细胞行为的能力。然而，最近的一项技术创新在生产具有适当规模和可裁剪几何特征的支架方面取得了明显的进步。这项最先进的技术被称为熔融电写(MEW)；这是一种高分辨率的3D打印版本，材料由合成聚合物产生，纤维以指定的方向和几何形状铺设，最重要的是，这种纤维在尺寸上更接近天然细胞外基质。MEW是由我的国际合作者--保罗·道尔顿教授(俄勒冈大学)发明的，该项目致力于在英国建立MEW，以创建更好的组织模拟结构，从而使我们能够更好地研究这些支架对细胞和组织行为的结构影响。更具体地说，这笔赠款专注于被称为基底膜的特殊组织的生长和组装。基底膜是存在于全身的一种基本组织。它们提供了细胞片和潜在的细胞外基质之间的互动点。在这里，它们充当控制各种细胞反应的信号中枢，包括确定细胞将成为的特定细胞类型，并保护这些细胞免受通过细胞外基质的机械力的影响。基底膜如何做到这一点是通过其组成(即组成)的局部和特定的差异以及这些蛋白质组装方式(即结构)的差异来实现的。虽然组成方面已经被广泛研究了很多年，但结构方面直到最近才开始出现。我们的主要假设是，细胞外基质的结构在其形貌和几何形状、硬度和孔径大小方面都将对基底膜如何在该基质上组装做出贡献。基底膜组装的这些差异将转化为细胞行为的变化。在这个项目中，我们将通过确定潜在的细胞外基质如何影响基底膜的组装和功能来检验这一假设。这是一个大而基本的问题，对哺乳动物生物学的许多方面至关重要，对退行性和与年龄相关的健康状况具有潜在的治疗意义。要有力地验证这一假设，历史上一直受到制作准确的实验模型的困难的阻碍，在该模型中，细胞外基质的特定方面可以被独立地修改，并对其贡献进行评估。然而，将MEW与我们现有的支架制造技术相结合，这代表了基板生产的一大进步，意味着我们现在能够精确地定制支架的特征，然后分析细胞和基底膜对这些支架的响应。因此，我们的项目有一个明确的目标：使用模仿细胞外基质的物理属性的支架制造技术来创建合成结构，这些技术模仿细胞外基质的物理属性，并继续影响基膜组装和细胞行为。

Tissue engineering commonly uses scaffolds that aim to mimic the structure of biological tissues; however, the scale and geometry of current approaches are dissimilar to those found in nature and these differences hamper the scaffolds' ability to support and control cell behaviour. A recent technological innovation however has led to a demonstrable advancement in producing scaffolds that possess appropriate scale and tailorable geometrical features. This state-of-the-art technology is called melt electro-writing (MEW); a high-resolution version of 3D printing where the material is produced from synthetic polymers, the fibre is laid down in defined orientations and geometries and, most importantly, where this fibre is much closer in size to the native extracellular matrix. MEW was invented by my International Collaborator - Prof. Paul Dalton (University of Oregon), and this project focuses on establishing MEW in the UK to allow superior tissue-mimic structures to be created that will then allow us to better study the structural effects of these scaffolds on cell and tissue behaviour. More specifically, this grant focuses on the growth and assembly of specialised tissues known as basement membranes.Basement membranes are an essential tissue present throughout the body. They provide the interaction point between sheets of cells and the underlying extracellular matrix. Here they act as signalling hubs controlling a wide variety of cellular responses including determining the specific cell types that the cells will become, and protecting these cells from the mechanical forces that move through the extracellular matrix. How basement membranes achieve this is through localised and specific differences in their make-up (i.e. composition) and by differences in the way those proteins are assembled (i.e. structure). Whilst the compositional aspects have been widely studied over many years, the structural aspects have only recently come to the fore.Our overarching hypothesis is that the structure of the extracellular matrix in terms of its topography and geometry, stiffness and pore size will each contribute to how basement membranes assemble on top of that matrix. Those differences in basement membrane assembly will then translate into changes in cell behaviour. In this project we will test this hypothesis by determining how the underlying extracellular matrix influences the way that basement membranes assemble and function. This is a large and fundamental question which is central to many aspects of mammalian biology and with potential therapeutic implications for degenerative and age-related health conditions. Robustly testing this hypothesis has historically been hampered by difficulties in producing accurate experimental models where the specific aspects of the extracellular matrix could be independently modified and their contribution evaluated. However, combining MEW with our existing scaffold fabrication technologies, which represents a step-change advancement in substrate production, means we are now able to precisely tailor the characteristics of the scaffolds and then analyse the cellular and basement membrane responses to these scaffolds.Our project therefore has one distinct aim: to create synthetic structures using scaffold fabrication technologies that mimic the physical properties of extracellular matrix topography, geometry and mechanics, and which go on to influence basement membrane assembly and cell behaviour.