Rapid localized cell trapping on biodegradable polymers using cell surface derivatization and microfluidic networking.

Spatial control over cell attachment is essential for controlling cell behavior and engineering cell-based sensor arrays. Here we report on a patterning procedure that can be utilized on a wide range of adherent and non-adherent cell types without the need to identify the exact peptide sequence or extracellular matrix (ECM) necessary for optimal cell attachment. This is achieved by converting native sialic residues present on the surface of most cells into non-native aldehydes using a mild sodium periodate treatment. The aldehyde groups are then reacted with biotin hydrazide to produce biotinylated cells. Avidin is patterned onto the surface of a biotinylated biodegradable block copolymer, polylactide-poly(ethylene glycol)-biotin (PLA-PEG-biotin) by microfluidic networking using a PDMS stamp. The biotinylated cells then bind specifically to the patterned avidin regions. The PEG that is presented from the PLA-PEG-biotin copolymer in the regions without avidin immobilization minimizes cell binding in the non-patterned regions.