Tunable Protein/Cell Binding and Interaction with Neurite Outgrowth of Low-Impedance Zwitterionic PEDOTs

Zwitterionic poly(3,4-ethylenedioxythiophene) (PEDOT) is an effective electronic material for bioelectronics because it exhibits efficient electrical trade-off and diminishes immune response. To promote the use of zwitterionic PEDOTs in bioelectronic devices, especially for cell alignment control and close electrocoupling, features such as tunable interaction of PEDOTs with proteins/cells and spatially modulating cell behavior are required. However, there is a lack of reliable methods to assemble zwitterionic EDOTs with other functionalized EDOT materials, having different polarities and oxidation potentials, to prepare PEDOTs with the aforementioned surface properties. In this study, we have developed a surfactant-assisted electropolymerization to assemble phosphorylcholine (PC)-functionalized EDOT with other functionalized EDOTs. By adjusting compositions, the interaction of PEDOT copolymers with proteins/cells can be finely tuned; the composition adjustment has an ignorable influence on the impedance of the copolymers. We also demonstrate that the cell-repulsive force generated from PC can spatially guide the neurite outgrowth to form a neuron network at single-cell resolution and greatly enhance the neurite outgrowth by 179%, which is significantly more distinctive than the reported topography effect. We expect that the derived tunable protein/cell interaction and the PC-induced repulsive guidance for the neurite outgrowth can make low-impedance zwitterionic PEDOTs more useful in bioelectronics.