Young's modulus of collagen at slow displacement rates

Collagen is a key structural component of extracellular matrix and its mechanical properties, particularly its stiffness, have been shown to influence cell function. This study explores the mechanical behavior of type I collagen gels at low rates relevant to that of cell motion. The Young's modulus, E, was obtained for collagen samples of concentrations 1.3, 2 and 3 mg/ml at varying crosshead displacement rates: 0.01, 0.1 and 1 mm/min. Local strain measurement in the gage section were used for both the strain and strain rate determination. The power law models for the modulus at these low strain rates show that the values converge as the displacement rate approaches a quasistatic state. This study provides data that was unavailable in the past on the Young's modulus of collagen at rates relevant to the cell.