Three-dimensional structure analysis of mouse nails using synchrotron radiation

Until now, studies on nail diseases have been performed through microscopic diagnosis and microscopic computed tomography (micro-CT). However, these kinds of conventional methods have some limitations. Firstly, the microscopic method is considered the gold standard for medical diagnosis. However, due to the use of fluorescent materials, the sample is damaged and it takes a long time to get results. Secondly, while micro-CT is a noninvasive method to get inner structure images of the sample with high resolution, the penetration and spatial resolution are insufficient for studying the microstructures of the sample, such as the sponge bone and the muscle fibers. In contrast, synchrotron radiation (SR) X-ray imaging technology has the advantage of very vividly demonstrating the anatomic structure of the sample with high penetration, sensitivity and resolution. In this study, we compared the optical microscopic method using hematoxylin and eosin staining and SR imaging to analyze the nail tissue in a mouse model. The results showed that SR could depict the inner structures of a mouse nail without any physical damage. Additionally, we could divide the important anatomical structures of the nail unit into three parts with three-dimensional (3D) images: the nail bed, nail matrix and hyponychium. The images showed that SR could be used for analyzing nails by visualizing the relatively clear and medically semantic structures in a 3D section. We expect that the results of this study will be applied to study nail diseases and conduct pharmaceutical research on their treatment.