Effect of Surface Potential on NIH3T3 Cell Adhesion and Proliferation

Cell adhesion is central to many cell behaviors including survival, differentiation, and motility. With the recent development of biomaterials and medical instrumentation, cell behaviors on artificial biosurfaces have gained attention from the research community. Self-assembled monolayers (SAMs) are known for their excellent ability to modify surfaces. To achieve more precise control of surface properties, mixed 6-amino-1-hexanethiol and 6-mercaptohexanonic acid were deposited on a gold substrate, and in a physiological environment, arbitrary zeta potentials between −187 and +6 mV were obtained. This binary SAM system elucidated the effect of surface potential on the adhesion and proliferation of NIH3T3 cells cultured on these surfaces. Cell adhesion, density, morphology, and proliferation were investigated by optical, fluorescence, and scanning electron microscopes. It was found that increased surface potential promoted cell attachment; hence, the initial cell density increased. However, the apparent proliferation rate decreased with increasing surface potential due to contact inhibition between adjacent NIH3T3 cells at higher density. When the initial density was low and cells did not contact each other, surface potential had little or no effect on proliferation. A more positive surface potential also changed the cell shape from bipolar to spreading and allowed more cell–cell and cell–substrate interactions due to the enhanced cell adhesion.