β-Phase poly(vinylidene fluoride) films encouraged more homogeneous cell distribution and more significant deposition of fibronectin towards the cell-material interface compared to α-phase poly(vinylidene fluoride) films

The piezoelectric response from beta-phase poly(vinylidene fluoride) (PVDF) can potentially be exploited for biomedical application. We hypothesized that alpha and beta-phase PVDF exert direct but different influence on cellular behavior, alpha- and beta-phase PVDF films were synthesized through solution casting and characterized with FT-IR, XRD, AFM and PPM to ensure successful fabrication of alpha and beta-phase PVDF films. Cellular evaluation with L929 mouse fibroblasts over one-week was conducted with AlamarBlue (R) metabolic assay and PicoGreen (R) proliferation assay. Immunostaining of fibronectin investigated the extent and distribution of extracellular matrix deposition. Image saliency analysis quantified differences in cellular distribution on the PVDF films. Our results showed that beta-phase PVDF films with the largest area expressing piezoelectric effect elicited highest cell metabolic activity at day 3 of culture. Increased fibronectin adsorption towards the cell-material interface was shown on beta-phase PVDF films. Image saliency analysis showed that fibroblasts on beta-phase PVDF films were more homogeneously distributed than on alpha-phase PVDF films. Taken collectively, the different molecular packing of alpha and beta-phase PVDF resulted in differing physical properties of films, which in turn induced differences in cellular behaviors. Further analysis of how alpha and beta-phase PVDF may evoke specific cellular behavior to suit particular application will be intriguing. (C) 2013 Elsevier B.V. All rights reserved.