Progressive structural and biomechanical changes in elastin degraded aorta.

摘要: Aortic aneurysm is an important clinical condition characterized by common structural changes such as the degradation of elastin, loss smooth muscle cells, and increased deposition fibrillary collagen. With goal investigating relationship between mechanical behavior structural/biochemical composition artery, this study used a simple chemical model investigated progressive in properties. Porcine thoracic aortas were digested mild solution purified elastase (5 U/mL) for 6, 12, 24, 48, 96 h. Initial size measurements show that disruption elastin structure leads to artery dilation absence periodic loading. The properties arteries, measured with biaxial tensile testing device, progress through four distinct stages termed (1) initial-softening, (2) elastomer-like, (3) extensible-but-stiff, (4) collagen-scaffold-like. While 1, 3, 4 are expected result degradation, S-shaped stress versus strain aorta resulting from enzyme digestion has not been reported previously. Our results suggest gradual can lead progression different thus reveal potential existence transition stage could contribute during formation.