Periodic microstructures of blood capillaries revealed by synchrotron X-ray multi-resolution microscopic analysis.

Cardiovascular diseases are closely related to structural blood capillaries lesions. Herein, microscopic investigations of mouse blood capillaries were performed at multiple spatial resolution by using synchrotron X-ray in-line phase contrast tomography and scanning transmission X-ray microscopy (STXM). The chemically fixed blood capillaries without any contrast agents were selected. For the first time, a periodic bamboo-shaped structure was observed at nanoscale resolution by STXM, and the three-dimensional tomographic slices at sub-micrometer resolution further confirmed the periodic wave profile of the blood capillaries. Then, a periodic microstructural model was suggested based on the microscopic images. By using high-performance imaging techniques, this work provides a better understanding of the relationship between the structure and function of blood capillaries, will be helpful in elucidating the causes of cardiovascular system diseases.