Human aortic elastin degrades with age in males but not females

Researchers analyzed purified elastin networks from 17 human thoracic aortas from donors aged 26 to 92 years, including nine males and eight females. The team conducted uniaxial tensile testing to determine tangent modulus at 1.1 stretch and examined microstructure using multiphoton microscopy, histology, and scanning electron microscopy. In male donors, elastin tangent modulus decreased significantly with age (p < 0.05). Older male tissues exhibited reduced fiber straightness (p < 0.05), increased fragmentation, and a significant decline in lamellar length (p < 0.05), aligning with electron microscopy findings of frayed fibers and diminished mechanical engagement under load. In contrast, female aortic samples showed no consistent age-dependent deterioration in mechanical or microstructural metrics.