Dynamic Electromechanical Hydrogel Matrices for Stem Cell Culture

Hydrogels have numerous biomedical applications including synthetic matrices for cell culture and tissue engineering. Here we report the development of hydrogel based multifunctional matrices that not only provide three-dimensional structural support to the embedded cells but also can simultaneously provide potentially beneficial dynamic mechanical and electrical cues to the cells. A unique aspect of these matrices is that they undergo reversible, anisotropic bending dynamics in an electric field. The direction and magnitude of this bending can be tuned through the hydrogel crosslink density while maintaining the same electric potential gradient, allowing control over the mechanical strain imparted to the cells in a three-dimensional environment. The conceptual design of these hydrogels was motivated through theoretical modeling of the osmotic pressure changes occurring at the gel-solution interfaces in an electric field. These electro-mechanical matrices support survival, proliferation, and differentiation of stem cells. Thus, these new three-dimensional in vitro synthetic matrices, which mimic multiple aspects of the native cellular environment, take us one step closer to in vivo systems. A multifunctional synthetic matrix that can simultaneously provide electrical and mechanical cues, in addition to providing structural support and chemical cues, is developed by combining novel bidirectional polyelectrolyte hydrogels with an optimized electrochemical cell. The matrix is shown to support stem cell growth, proliferation, and differentiation in a 3D environment. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.