Ionic-Liquid-Based Electroactive Polymer Composites for Muscle Tissue Engineering

Abstract

As an electromechanically active tissue, muscle regeneration takes advantage of active scaffolds providing mechanoelectrical stimuli and a biomimetic microenvironment. Thus, this study reports on the preparation of ionic electroactive materials based on ionic liquids (ILs) and poly(vinylidene fluoride) (PVDF). IL/PVDF composites with 10, 20, and 40% wt. of 1-butyl-3-methylimidazolium chloride [Bmim][Cl] and 2-hydroxyethyl-trimethylammonium dihydrogen phosphate [Ch][DHP] were prepared by solvent casting. It is shown that the inclusion of [Bmim][Cl] and [Ch][DHP] both improves the electrical conductivity and induces the PVDF crystallization in the polar β-phase. Further, the introduction of the IL also influences the thermal stability of the composites. [Bmim][Cl]/PVDF composites show larger Young moduli and a larger increase of the electrical conductivity than the [Ch][DHP]/PVDF composites. It is also shown that [Bmim][Cl] composites show a piezoresistive response, with gauge factors from 1 to 2.5, allowing them therefore to work as electromechanical sensors in biomechanical applications. The noncytotoxicity of the IL/PVDF composite films and C2C12 cell proliferation demonstrates the applicability of the composites as a suitable platform for muscle regeneration strategies.