Patterning bio-molecules for cell attachment at single cell levels in PDMS microfluidic chips

We demonstrate an integration method of protein patterns in microfluidic chambers which allow cell attachment at single cell level and long term cell culture. This method is based on photolithography and reactive ion etching of protein layer well immobilized on a substrate and protected with a water-soluble protection layer. After patterning, the protein pattern is integrated into a microfluidic device made of polydimethylsilane (PDMS). Since the protein pattern is protected, oxygen plasma can be applied for irreversible device bonding. Afterward, the protection layer is removed in a water flow for ten minutes. To test the long term culture performance, h-TERT-RPE1 cells (infinity telomerase-immortalized retinal pigment epithelial human cells) have been used and we observed significant change of cell morphology. Indeed, because of the well designed surface pattern and microfluidic environment, cells can form highly elongated features that can not be observed with protein pattern or in a micro-chamber alone. (C) 2009 Elsevier B.V. All rights reserved.