Southampton Imaging: 3D imaging at millimetre to nanometre scales for regenerative medicine using multiple complimentary modalities

再生医学旨在使组织和器官修复受损和患病的组织，使身体恢复到原来的健康状态。它使用干细胞和前体细胞，在完全正确的条件下，这些细胞将转变为修复组织所需的特化细胞。细胞可以在其上生长和被引导的支架被用来帮助细胞组织成正确的结构。我们现在处于一个独特的位置，可以创造新的软组织和硬组织(如肝脏、神经、软骨、骨骼)来帮助治疗所有人。在这个转移到临床应用的目标中，重要的是确保新形成的组织是完全安全的。决定组织有效性和正常功能的最重要的因素之一是它的结构或排列方式(组织的架构就像一座桥)。这种组织结构在许多不同的尺度上都很重要，从单个细胞组件到器官供应的骨骼或血管和神经等结构的大规模组织。因此，为了了解所需的适当结构，并检查所构建的组织结构是否正确运行，我们需要能够通过使用不同放大倍数的显微成像来‘看到’这些结构。由于细胞和组织是三维(3D)结构，我们需要了解它们在3D中是如何组合在一起的，以了解它们的架构--同样地，我们可以通过在建筑物周围走动来了解建筑元素如何在3D中组合在一起并有效地发挥作用。这个应用程序适用于三个专门设计的成像系统，用于创建3种不同比例的组织和支架的3D图像。最高的放大倍率是由扫描电子显微镜和切片机相结合提供的-这会逐渐从样品中去除非常薄的(&lt；50 nm)切片，成像每个切片后显露的表面。这产生了一堆图像，代表了细胞的结构，包括组成细胞的组件和支架的精细细节--通过这种技术，可以清楚地看到细胞内的膜。下一级放大使用的是光学显微镜，它能照射一层非常薄的光(4-10微米)。这使我们能够在不切割的情况下查看更大的组织块(最大可达1厘米立方体-一个糖立方体)，并再次创建3D图像堆栈来表示这一点。单个细胞很容易被看到，它们可以被标记，这样我们就可以识别细胞类型，并随着时间的推移跟踪它们。然而，有些样品光无法穿透或太大--对于这些样品，第三种仪器使用了高分辨率的MicroCT(计算机断层成像)成像设备。它使用X射线在不损坏大样本的情况下对它们进行成像，这种新仪器的设计可以让我们以一种目前无法做到的方式区分单个细胞及其一些特征。这些系统将增加南安普敦现有的由12名成像专家支持的广泛的成像设备。样品制备和生物图像解释方面的现有专业知识对于有效使用这些尖端成像技术至关重要。在所有尺度的3D成像中，另一个问题是生成的非常大的数字图像集-每个图像集需要大量的存储空间；50-1000 GB(相当于每个DVD 10-200张！)南安普顿大学是先进计算和图像处理领域的世界领先者--我们已经拥有最先进的计算硬件和软件。在这个项目中，我们将与我们在大学的合作者合作，进一步开发专门用于处理和分析再生医学样本图像的工具。我们预计再生医学将在未来10-30年内改变人类健康，为了尽可能快速和安全地实现这一承诺，我们必须对生成的结构和组织进行成像。

Regenerative medicine aims to make tissues and organs to repair damaged and diseased tissues and restore the body to its original health. It uses stems cells and precursor cells that, under exactly the right conditions, will change into the specialized cells needed to repair the tissue. Scaffolds upon which the cells can grow and be guided are used to help organize the cells into the right structures. We are now in a unique position to create new soft and hard tissues (e.g. liver, neural, cartilage, bone) to help aid treatment for all. Important in this goal of moving to clinical application will be to ensure the new formed tissue is completely safe.One of the most important factors that determines the effectiveness and normal functioning of a tissue is the way it is structured or arranged (the architecture of the tissue- like a bridge). This tissue architecture is important at many different scales, from individual cell components to the large scale organization of structures such as bones or blood vessels and nerves supplying the organs. Therefore to understand the appropriate structures required and check that the tissue constructs made are performing correctly we need to be able to 'see' these by using microscopic imaging at different magnifications. Because the cells and tissues are three-dimensional (3D) structures, we need to see how they fit together in 3D to understand their architecture - in the same way we can understand how the elements of a building fit together and function effectively in 3D by walking around it. This application is for three imaging systems specially designed to create 3D images of tissues and scaffolds at 3 different scales. The highest magnification is provided by a scanning electron microscope combined with a microtome- this gradually removes very thin (<50nm) slices from the sample imaging the surface that is revealed after each slice. This creates a stack of images representing the structure of the cells down to the components making up the cells and the fine detail of scaffolds- with this technique the membranes within the cells can clearly be seen. The next level of magnification uses a light microscope that shines a very thin sheet of light (4-10 micro meters). This allows us to look at much larger blocks of tissue (up to a cm cube - a sugar cube) without cutting it and again create a 3D image stack to represent this. Individual cells are easily seen and they can be labelled so we can identify cell types and track them over time. However there are some samples that light will not penetrate or that are too large - for these samples the third instrument, a high resolution microCT (computed tomography) imaging device is used. This uses X-rays to image through large samples without damaging them and the design of this new instrument can allows us to distinguish individual cells and some of their features in a way that is not currently possible.These systems will add to the wide range of existing imaging facilities in Southampton that are supported by 12 expert imaging staff. The existing expertise in sample preparation and biological image interpretation is essential for these cutting edge imaging techniques to be used effectively. An additional problem in 3D imaging at all scales is the very large digital image sets that are produced- each taking large amounts of storage; 50-1000Gb (equivalent of 10-200 DVDs each!). Southampton University is a world leader in advanced computing and image processing - we already have state of the art computing hardware and software. In this project we will work with our collaborators in the University to further develop these specifically for the processing and analysis of images of regenerative medicine samples. We expect regenerative medicine to transform human health over the next 10-30 years and in order to fulfill this promise as quickly and safely as possible it is essential we can image the generated structures and tissues.