Measuring the Young's Moduli of Sugar Cross-linked Native Type I Collagen Fibrils

Collagen is the most important structural protein in the human body, providing tissues with increased structural rigidity and elasticity. Through ageing, collagen-containing tissues such as the myocardium stiffen. This gradual loss in tissue elasticity can lead to pathogenesis, and can further be expedited through diabetes mellitus. This stiffening may be attributed to collagen cross-linking initiated through prolonged exposure to reducing sugars in blood. Atomic force microscopy (AFM) was employed to image native collagen fibrils, and measure their reduced Young’s moduli via nanoindentation, to quantify the impact of sugar-induced cross- linking. Comparing control and D-ribose-incubated (sample) fibrils revealed a statistically significant difference between their average reduced moduli, which was observed in collagen fibrils exposed to glutaraldehyde, a standard biological cross-linker. D-ribose-induced cross-linking was verified by sample fibrils displaying resistance to acid degradation via monitoring their turbidity. These experimental findings revealed an increase in collagen fibril stiffness due to D-ribose-induced cross-linking.M.Sc