Micro-patterned films of bio-functionalized conducting polymers for cellular engineering.

Abstract

Conducting polymers (CPs) are easy to process and have tunable physical and chemical properties including conductivity, volume, color, and hydrophobicity. Therefore, these organic polymers are attractive in a broad spectrum of bioelectronic applications ranging from implantable electrodes to biosensors and actuators. Patterned films of CPs, especially with various surface chemistries, provide versatile and sophisticated building-blocks for bioelectronics. In this context, we recently introduced a simple and efficient technique of hydrogel-mediated electropolymerization to directly pattern films of PPy (polypyrrole) with spatially-addressable chemistries. This technique employs a topographically patterned hydrogel stamp to deliver polymer precursors to the surface of electrode during the PPy electropolymerization. This method enables easy incorporation of different molecules into CP film during the polymerization. Herein, we aim to extend the scope of hydrogel-mediated electropolymerization to pattern other types of CPs and to explore the potential of bio-functionalized CP films for cell adhesion studies. Using this method, patterned films of two distinct CPs, PPy and PEDOT, were generated with a number of dopants. The produced films were characterized for morphology, impedance, and chemical composition. Patterned CP films were bio-functionalized by incorporation of a laminin peptide into these films. Lastly, the resultant substrates were tested for cell adhesion where laminin-doped CP showed a higher level of cell adhesion compared to PSS (polystyrene sulfonate)-doped CP films. These results together demonstrate the potential application of patterned films of bio-functionalized CPs for cellular engineering.