Cellular traction force measurement based on patterned elastic substrate

Abstract

Abstract： Cell traction force microscopy method is one of the mainstream tools for measuring cell traction force, which uses fluorescent microbeads as markers to measure the deformation of the substrate and calculate cell traction force. However, due to the random distribution of fluorescent microbeads in the substrate, the calculation accuracy of the cell traction force field maybe affected. To address the problem of uncontrollable depth of fluorescent microbeads, a method using patterned elastic substrate was proposed to measure cell traction forces, in which the micropattern arrays fabricated on the surface of substrate was used as deformation markers. A micro-pad array with diameter of 3 µm and height of 0.8 µm was designed and fabricated on the polydimethylsiloxane substrate surface as the displacement markers. In the finite element simulation, external forces mimicking cell traction forces was applied at different locations on the substrate surface and the displacements field of the micro-pad array was obtained. Using the displacements field obtained by simulation, the traction force field was calculated through the traction force inversion algorithm, and the results were consistent with the input external forces in the simulation. The patterned elastic substrates were validated by mapping neonatal rat ventricular myocytes contraction forces. Both simulation and experiment demonstrate that the capacity of patterned elastic substrate for generating accurate cell contraction force maps, providing new research method for pathological study of myocardial diseases.

Keywords

• cell traction force mapping
• patterned substrates
• finite element simulation
• traction force inversion