Polyvinylidene fluoride for proliferation and preservation of bovine corneal endothelial cells by enhancing type IV collagen production and deposition

In this study, biomaterials with different hydrophobic properties including polyvinyl alcohol (PVA), poly(ethylene-co-vinyl alcohol) (EVAL), tissue culture polystyrene (TCPS), and polyvinylidene fluoride (PVDF) were examined in the bovine corneal endothelial cells (BCECs) culture system to elucidate their possible impact on clinical demand and scientific interest. It was found that BCECs were inhibited to attach onto the PVA surface. Conversely, relatively more hydrophobic biomaterials EVAL, TCPS, and PVDF successfully initiate BCEC adhesion. Compared to EVAL, cultured BCECs on TCPS and PVDF exhibited higher viability. Furthermore, fibroblastic transformation on EVAL and TCPS was observed at day 17, but BCECs maintained typical hexagonal shape on the PVDF surface at day 21. This phenomenon can be rescued by previously coating type IV collagen on TCPS but not on EVAL. In addition, when BCECs were cultured on PVDF, the expressions of gap junction connexin-43, differentiation marker N-cadherin, and tight junction ZO-1 were well-developed, resembling the physiological phenotypes. After examining the type IV collagen expression by Western blot analysis and protein absorption test, a possible explanation for the better proliferation and preservation of BCECs on the PVDF substrate is that PVDF is a bioactive substratum which enables BCECs to synthesize and reserve more extracellular matrix type IV collagen, paving an important way to provide a more preferential environment for BCEC cultures. Accordingly, promoting CEC growth effects after cell-biomaterial association may be applied to the tissue engineering of corneal endothelium.