Controlling cell adhesion on thermoresponsive P(MEO2MA-co-OEGMA) substrates

Thermoresponsive polymer (TRP) substrates as in vitro cell culture platforms have recently gained popularity due to their ability to release cells without biochemical enzymes and while maintaining cell-cell and cell-matrix interactions. Cells grown on TRPs are released from their culture surface by a change in temperature below the lower critical solution temperature (LCST) of the polymer under aqueous conditions. P(MEO₂MA-co-OEGMA) substrates offer a unique advantage over PNIPAM, the gold standard: the ability to tune the LCST. These TRP brushes exhibit aqueous LCST values between 28 and 90°C, which can be precisely adjusted by varying the co-monomer composition. In this work, we investigated the cellular response to culture on P(MEO₂MA-co-OEGMA) substrates using a variety of techniques: 1) immunofluorescence and confocal microscopy was utilized to examine cell morphology, 2) single-gene RT-PCR was used to examine differences in gene expression of cell adhesion markers, and 3) microarray analysis was utilized to elucidate differences in the mechanism of initial cell spreading. Results show an increase in cell adhesion and cell adhesion-related biomarkers as a function of LCST, with more hydrophobic surfaces displaying an increase in cell spreading. An increase in cell height also appears to be correlated with increasing LCST. In conclusion, P(MEO₂MA-co-OEGMA substrates can be used to control cell adhesion in tissue engineering applications.