Full-field laser speckle contrast imaging for shear wave measurements of 3D cell culture systems

The biochemical and biomechanical properties of the extracellular matrix (ECM) contribute to the regulatory functions of the cell microenvironment, which is vital for cell development and tissue homeostasis. Studies have shown that the stiffness of the ECM can promote growth, apoptosis or cell migration. Thus, the analysis of the three-dimensional (3D) matrix stiffness may provide information about the dynamics of the cancer cell and its microenvironment during disease progression and treatment. In this report, a shear wave imaging system based on laser speckle contrast imaging was used to measure the local shear modulus of the 3D cell culture quantitatively. The temporal study has shown that the stiffness of the cell matrix is related to the length of the culture period, where the increased of the cell matrix stiffness is correlated with the structural changes in the ECM, such as formation of fiber bundles and network.