Effect of water vapor on the surface characteristics and cell compatibility of zein films

In this study, zein microsphere films were fabricated via a solution casting method, and their surfaces were subsequently treated with a higher relative humidity. Changes in surface properties were characterized by contact-angle measurement and scanning electron microscopy (SEM). Human hepatoma cells (BEL-7402) were used as model cells to evaluate cell adhesion, spreading and proliferation on zein films before and after treatment. Additionally, the adhesion and morphologies of rat platelets on zein films were also investigated to evaluate the blood compatibility of the films. The results showed that the hydrophilicity of zein films was changed after treatment, and the surface morphology varied, gradually becoming more smooth and the microspheres in the films disappeared. As the result, the adhesion and proliferation of BEL-7402 cells were significantly improved, while HUVECs were more sensitive than BEL-7402 cells to cell-substrate interactions. Adhesion of rat platelets could be inhibited on the treated zein films. The results suggest that the synergistic actions of hydrophilic properties and micro morphologies are responsible for the cell behaviors.