Optimization of Protein Immobilization in Microfludic Devices for Circulating Tumor Cell Capture

Abstract

The isolation of metastatic circulating tumor cells (CTCs) within the blood using microfluidic devices is a promising method for the detection of cancer. In this study, protein patterning of endothelial-leukocyte adhesion molecule-1 (E-selectin) and anti-epitheal-cell-adhesion-molecule (Anti-EpCAM) within microfluidic channels is utilized to improve the capture efficiency. To create this protein patterning the protein immobilization method must first be optimized to allow for maximum capture of CTCs and minimal increase in the flow rate of cells through the device due to added coating thickness. Proteins are immobilized in alternating regions using photo-initiated graft polymerization of polyacrylic acid (PAA) and a silanization reaction. Using interferometer measurements and fluorescent tagging, PAA height was minimized and protein immobilization was optimized.