Porous Stimuli-Responsive Self-Folding Electrospun Mats for 4D Biofabrication.

We report fabrication and characterization of electrospun, porous multi-layer scaffolds based-on thermo-responsive polymers polycaprolactone (PCL) and poly(N-isopropylacrylamide). We found that the electrospun mats fold into various 3D structures in an aqueous environment at different temperatures. We could determine the mechanism behind different folding behaviors under different conditions by consideration of the properties of the individual polymers. At 37 °C in an aqueous environment, the scaffolds spontaneously rolled into tubular structures with PCL as the inner layer, making them suitable for cell encapsulation. We also demonstrated that the cell adhesion and viability could be improved by coating the polymers with collagen, showing the suitability of this scaffold for several tissue engineering applications.