In vitro growth and differentiation of primary myoblasts on thiophene based conducting polymers

Polythiophenes are attractive candidate polymers for use in synthetic cell scaffolds as they are amenable to modification of functional groups as a means by which to increase biocompatibility. In the current study we analysed the physical properties and response of primary myoblasts to three thiophene polymers synthesized from either a basic bithiophene monomer or from one of two different thiophene monomers with alkoxy functional groups. In addition, the effect of the dopants pTS^- and ClO₄ ^- was investigated. In general, it was found that pTS^- doped polymers were significantly smoother and tended to be more hydrophilic than their ClO₄ ^- doped counterparts, demonstrating that the choice of dopant significantly affects the polythiophene physical properties. These properties had a significant effect on the response of primary myoblasts to the polymer surfaces; LDH activity measured from cells harvested at 24 and 48 h post-seeding revealed significant differences between numbers of cells attaching to the different thiophene polymers, whilst all of the polymers equally supported cell doubling over the 48 h period. Differences in morphology were also observed, with reduced cell spreading observed on polymers with alkoxy groups. In addition, significant differences were seen in the polymers' ability to support myoblast fusion. In general pTS^- doped polymers were better able to support fusion than their ClO₄ ^- doped counterparts. These studies demonstrate that modification of thiophene polymers can be used to promote specific cellular response (e.g. proliferation over differentiation) without the use of biological agents.