Thermal induced coupling of cell adhesion/deadhesion and migration under HBV replication and EGCG treatment
Date of Issue2011
School of Chemical and Biomedical Engineering
The unique physical property of thermo-responsive polymer (TRP) has recently prompted its increasing applications in the applications of tissue engineering and regeneration medicine. On the other hand, TRP has never been exploited for their potential applications in quantitative cell screening against various external stimulations. In the first part of my thesis, TRP was applied as a model system for elucidating the effect of HBV replication on the biophysical responses of HepG2 cells transfected by wild type HBV genome. Moreover, mutant HBV genome is designed to assess the specific activity of the SH3-binding domain of HBx during HBV replication. The adhesion contact recession and geometry transformation of HepG2 cells transfected with empty vector (pcDNA3.1 cells), wild type HBV (wtHBV cells) and mutant HBV genome (mHBV cells) were probed during the thermal transformation across lower solution critical temperature of TRP. In comparison with pcDNA3.1 cells and mHBV cells, the initial rate of reduction in degree of deformation and average adhesion energy for wtHBV cells was significantly increased. Interestingly, migration speed and persistence time of cells were found to be correlated with the cell deadhesion kinetics. Immuno-fluorescence microscopy demonstrates that HBV replication reduces the actin concentration and focal adhesions at cell periphery during the initial 30 min cell deadhesion. The results strongly suggested that HBV replication triggers the dynamic responses of HepG2 cells through the cytoskeleton remodeling and subsequent mechanochemical transduction. Overall, it is shown that TRP provides an exciting platform for quantifying biological stimulations on adherent cells.