Polydopamine-assisted shape memory of polyurethane nanofibers with light-induced tunable responsiveness and improved cell adhesiveness

Abstract

Compared with the typical stimulus of heat, which is difficult to manipulate under some actual conditions, light-induced mode to shape memory polymers(SMPs) can act as more ideal ones benefiting from the characteristics such as remote control, focused accuracy and rapid switched responses. Herein, inspired by the strong adhesion and efficient photothermal conversion of polydopamine (PDA) coatings, light-induced tunable shape memory of poly(ε-caprolactone)(PCL)-based polyurethanes (SMPUs) with better cell adhesiveness were fabricated by a post-synthesis approach of PDA onto the surfaces of micro/nanofibers to substitute its original thermo-responsiveness. The characterizations of the adjustable thickness of the coatings were detected by fourier transform infrared spectroscopy(FTIR) and the morphology was characterized by scanning electron microscopy (SEM). Shape memory behaviors of the PDA/SMPU fibers were investigated in details by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and shape fixation/recovery angles detection. Moreover, by selecting bone marrow stem cells (BMSCs) as model, the viability and proliferation with the cell seeded onto were systematically characterized. The tenability of light-induced shape memory effects, their excellent cytocompatibility, and the more favorable for BMSC’s survival with better adhesion of osteoblast cells onto all these PDA-coated SMPU (PDA/SMPU), make it promising candidates for potential bone repairing and healing.