Preparation of biopolymeric micropatterns via non-residual-layered imprinting technique and its application to modify single-celled microelectrodes

摘要

A ‘‘patch clamp’’ microelectrode modified on the surface for single cell adhesion and growth was developed using a novel polymer-transfer technique to deposit cell-adhesive polymer layers on the substrate platform. Several hydrophilic polymers–-polyvinyl pyrrolidone, chitosan, alginic acid, and gelatin were successfully transferred onto the platform in order to enhance cell adhesion. The process was developed to apply a PDMS stamp pre-adhered with a phosphorylcholine (PC) layer on the protruding areas of the pattern, followed by adsorbing an adhesive polymer to imprint the adhesive layer onto the platform. Plasma activation on the stamp, adsorbed polymers, and/or the substrate was evaluated to provide an accessible method to obtain a nanothick (about 180 nm) polymeric film without any residual layer. XPS characterization on the platform verified that the bioactive polymer was only transferred and coated on the convex surfaces of the pattern. From observing the cell adhesion on the chitosan-modified platform, the number of adhered cells on the chitosan layer was found to be greater than that on the original poly(glycidyl methacrylate) (PGMA) layer, corresponding with the prediction that chitosan can serve as the cell-adhesive layer. The modified patterns were found to confine a single cell on each convex top of the platforms.