Chang A C, Liu B H, Shao P L, Liao J D
Department of Materials Science and Engineering, National Cheng Kung University, Tainan City, Taiwan.
J Microsc. 2017 Sep;267(3):265-271. doi: 10.1111/jmi.12562. Epub 2017 Mar 23.
The multilayer skin provides the physical resistance and strength against the environmental attacks, and consequently plays a significant role in maintaining the mammalian health. Currently, optical microscopy (OM) is the most common method for the research related to skin tissues while with the drawbacks including the possibility of changing the native morphology of the sample with the addition of the chemical or immunological staining and the restricted resolution of images for the direct observation of the tissue structures. To investigate if the function of each tissue is structure-dependent and the how the injured skin returns to the intact condition, we applied atomic force microscopy (AFM) on the sectioned mice-skin to reveal the tissue structures with a nanoscale resolution. From the outermost stratum to the inner layer of the skin tissue, the respectively laminated, fibrous, and brick-like structures were observed and corresponded to various functions. Due to the mechanical differences between the tissue constituents and their boundaries, the sizes and arrangements of the components were characterised and quantified by the mechanical mapping of AFM, which enabled the analytical comparisons between tissue layers. For the wound model, the skin tissues were examined with the initial formation of blood vessels and type-I collagen, which agreed with the stage of healing process estimated by OM but showed more detail information about the evolution of proteins among the skin. In conclusion, the characterisation of the components that consist of skin tissue by AFM enables the connection of the tissue function to the corresponded ultrastructure.
多层皮肤提供了抵御环境攻击的物理抗性和强度，因此在维持哺乳动物健康方面发挥着重要作用。目前，光学显微镜（OM）是研究皮肤组织最常用的方法，但其存在一些缺点，包括添加化学或免疫染色可能改变样本的天然形态，以及直接观察组织结构时图像分辨率受限。为了研究每个组织的功能是否依赖于结构，以及受损皮肤如何恢复到完整状态，我们对切片的小鼠皮肤应用原子力显微镜（AFM），以纳米级分辨率揭示组织结构。从皮肤组织的最外层到内层，分别观察到分层、纤维状和砖状结构，它们对应着不同的功能。由于组织成分及其边界之间的力学差异，通过AFM的力学映射对成分的大小和排列进行了表征和量化，这使得能够对组织层进行分析比较。对于伤口模型，检查了皮肤组织中血管和I型胶原蛋白的初始形成情况，这与通过OM估计的愈合过程阶段一致，但显示了关于皮肤中蛋白质演变的更多详细信息。总之，通过AFM对构成皮肤组织的成分进行表征，能够将组织功能与相应的超微结构联系起来。
