Mechanical Property Control Of Polyacrylamide Gel Application For Cell Culture In Vitro

The mechanical environment for cell growth has a significant impact on its biological behavior. To a great extent, cell migration and morphology phenotype are influenced by substrate rigidity. Currently, there is a universal and outstanding issue that rigidity of substrate (glass or plastic culture capsule) differs with cell growth environment in vitro. Thus, it gives rise to a great deviation between the experimental results and actual biological behavior of cells in vivo. Therefore, it is of great significance to study the response of cells to the mechanical environment quantitatively, correctly understanding the key link of the occurrence and development of above diseases and looking for effective means of treatment and prevention. Establishing in vitro cell culture model which substrate mechanical properties can be controllable is the important part of the observation and study.In order to construct the in vitro cell culture model occurring in biochemical and biophysical environment in vivo, and to establish quantitative detection and control of mechanical properties of substrate, a low modulus material polyacrylamide hydrogel (PAHG) was synthesized and used as the substrate material for in vitro cell culture. Using a modified tensile device based on the principles of buoyancy for balance out gravity deformation and by detecting the minor deformation with the aids of computer graphic processing software, the measurement of low elastic modulus (E) of PAHG was established. By analyzing a large number of experimental data, the effect of two key factors (molar ratio of cross-linker/monomer and water content) on elastic modulus was investigated, and the influence of cross-linker/monomer (d) on saturated water content (w) was also discussed. Mathematical model for d, w and E of water saturated gel in vitro cell culture state was built up by regression analysis of experimental data. Based on the model, the d for PAHG with a given elastic modulus in water saturated state was calculated and applied to the synthesis of PAHG. The results showed that the elastic modulus of thus-obtained PAHG in water saturated state is in agreement with the given value with a relative error of 0.025-0.12, suggesting that the mathematical model is applicable for the prediction of properties of low modulus materials. In this research, PAHG which stiffness is controlled by mathematical model is prepared to investigate hepatic parenchymal cells biological behavior when they are cultured on substrate with different rigidity. The influence of tissue rigidity and cell phenotypes was also discussed.