Fig. 1

Scanning electron microscopy (SEM, a-b, greyscale) and confocal images (c-d, false colour red) showing the 3D polymer scaffolds and Arabidopsis thaliana cell growth in the scaffolds. a-b SEM images of 30 % PLA nanofibres, 70 % PET microfibre scaffold before cell seeding: a front-view, b side-view. c-d 3-dimensional reconstructions of confocal z-stacks showing cells of Arabidopsis thaliana expressing a reporter construct expressing cytoplasmic mCherry: c day 1 and d day 4 growth of cells inside the scaffold. Proliferation and growth were observed throughout the scaffold. Cells increased in number and size from day 1 to day 4. Cells formed local points of attachment on the fibres (arrows) and subsequently expanded in size into the porous space either by stretching from or winding around microfibres. For example, arrows 1 and 2 point to a cell attached to a microfibre at point 1 and growing into the depth of the fibrous scaffold as shown at point 2. Arrow 3 highlights a cell wrapping around a microfibre. Scale bars: 100 μm