Towards 4D printed scaffolds for tissue engineering: exploiting 3Dshape memory polymers to deliver time-controlled stimulus oncultured cells

摘要

Tissue engineering needs innovative solutions to better fit the requirements of a minimally invasiveapproach, providing at the same time instructive cues to cells. The use of shape memory polyurethanehas been investigated by producing 4D scaffolds via additive manufacturing technology. Scaffolds withtwo different pore network configurations(0/90° and 0/45°)were characterized by dynamicmechanical analysis. The thermo-mechanical analysis showed a Tg at about 32 °C(Tg = Ttrans),indicating no influence of the fabrication process on the transition temperature. In addition, shaperecovery tests showed a good recovery of the permanent shape for both scaffold configurations. Whencells were seeded onto the scaffolds in the temporary shape and the permanent shape was recovered,cells were significantly more elongated after shape recovery. Thus, the mechanical stimulus impartedby shape recovery is able to influence the shape of cells and nuclei. The obtained results indicate that asingle mechanical stimulus is sufficient to initiate changes in the morphology of adherent cells.