Preparation of transparent zein films for cell culture applications.

In our previous studies, zein has shown good cell compatibility in both films and porous scaffolds. To use the zein film in microfluidic devices or as a cell culture substrate, swelling and excessive degradation should be avoided. Moreover, the film should be transparent. In this study, we found that the zein film could maintain good transparency even after swelling when it was treated for 20min at 121°C, 100% relative humidity and 103.4kPa, especially for the zein film without the addition of a plasticizer. FT-IR and XRD analysis showed that the ratio of α-helix of zein structure decreased and the ratio of its β-sheet increased. Proliferation of NIH 3T3 cells on the transparent zein film was as cytocompatible as the untreated one and the cell culture plate. The improved transparency of zein films after swelling will expand the application field of zein.