Figure 1: Electrospun membrane functionalized with laminin fragment.

(a) Schematic representation of basement membrane breakdown and biomaterials approach. Cells undergo phenotype alterations, accompanied by an upregulation of active MMPs that results in the degradation of the basement membrane. The action of active MMPs exposes cryptic ECM information such as the laminin β1-fragment. (b) Schematic representation of the proposed material developed to prevent increased MMP activity as a response to TGFβ1. A PCL membrane is functionalized with a fragment of the laminin β1-chain via a pDA coating and directly interfaced with an epithelial cell layer. (c–f) Scanning electron micrographs of air plasma-treated (AP) electrospun PCL membranes (c) before and (d) after 1 h, (e) 4 h and (f) 24 h incubation in a 2 mg ml⁻¹ dopamine solution to apply a pDA coating. Scale bars, 10 μm; magnification: × 1,000. Insets contain photographs of the membranes. (g) Raman spectra of (black trace) as-made membranes, as well as AP membranes (blue trace) before and (red trace) after pDA coating (4 h). (h–k) Confocal images of membranes coated with pDA for 4 h after incubation with (h) 0 μg ml⁻¹, (i) 10 μg ml⁻¹ and (j) 100 μg ml⁻¹ fluorescein isothiocyanate-labelled laminin β1-fragment for 8 h at 37 °C. Scale bars, 150 μm. (k) Total internal reflection fluorescence image of pDA-coated electrospun PCL fibres after incubation with 10 μg ml⁻¹ fluorescein isothiocyanate-labelled laminin β1-fragment for 8 h at 37 °C. Scale bar, 5 μm.