Numerical Test for Cell Durotaxis Migration on Substrate with Moderate Gradient Stiffness / 医用生物力学

ABSTRACT

Objective Based on fibroblast cell model and photopolymerized hydrogel substrate with moderate gradient stiffness, to analyze the effect of process and performance parameters on cell migration and provide theoretical guidance for artificial scaffold design and fabrication. Methods A mathematical model of the test system was built and the corresponding numerical program was compiled, including viscoelastic dynamic finite element of the cell model, reaction kinetic equation of focal adhesions, and the strategy to deal with dynamic boundary and multi-scale time. Results The relationship between process parameters and performance parameters was formulated based on experimental data; cell migration speed and traction increased with the substrate stiffness increasing and were accompanied by rapid fluctuation when stiffness gradient was constant, then cell movement gradually stabilized with the extension of observation time. Increasing stiffness gradient moderately obviously promoted cell migration, and cells could maintain a limited speed on substrate with a large stiffness gradient. Smaller photomask opacity gradient resulted in larger substrate stiffness gradient and less time spent for cell to reach the target. These results agreed with the experimental results reported in the literature. Conclusions The experimental result provided an effective digital simulation platform to test the influence of process and performance parameter of photopolymerized hydrogel substrate with moderate gradient stiffness on cell migration.