Contractile behaviors of cardiac muscle cells on mushroom-shaped micropillar arrays.

In this work we propose mushroom-shaped PDMS (Polydimethylsiloxane) μpillar arrays for enhancing the contractile force of cardiomyocytes during cell culturing. Conventional micropillar (μpillar) arrays with flat surfaces were employed as a standard sample to quantitatively recognize experimental data and to conclusively demonstrate the improved performance of mushroom-shaped PDMS μpillar arrays. Cardiomyocytes isolated from experimental animals were cultured on both of the fabricated μpillar arrays and then monitored over a growing period. Deflections of μpillars were precisely measured through a home-built analyzing system quantitatively representing the contractile force of cardiomyocytes. Mushroom-shaped PDMS μpillar arrays exhibited a 20% improved contractile force compared to conventional PDMS μpillar arrays due to their topographical dependency. Preliminary results also show that the proposed mushroom-shaped PDMS μpillar surface positively affects the Z-band width, actin filament polymerization and focal adhesion (FA) of cardiomyocytes. Further, the enhanced performance of mushroom-shaped PDMS μpillar arrays was confirmed by measuring the cardiac sarcomere α-actin length and myofilament width via ICC (immunocytochemistry) staining and western blot experiments.