Magnetic polyurethane-based electrospun scaffolds: a linkage between magnetically enhanced bioactivity with shape memory effect for smart wound healing application

In this study, different shape memory polyurethane (SMPU)-based electrospun nanofibers containing Fe3O4 magnetic nanoparticles (MNPs) were prepared. The shape-memory behavior of these scaffolds enables minimally invasive applications within biological systems, while their magnetic properties enhance the growth, proliferation, and differentiation of the bone cells. SMPU was synthesized via a two-step pre-polymerization method. The effects of MNPs on hydrogen bonding, crystallinity, thermal properties, hydrophilicity, water absorption, and mechanical and shape memory properties of SMPU were investigated. The results revealed that MNPs restricted the hydrogen bonds formation and promoted microphase separation in SMPU hard and soft segments. Moreover, a reduction in the degree of crystallinity of oft segments in the SMPU nanocomposites was observed by the addition of MNPs. Scanning electron microscopy was employed to determine the average diameters and size distributions of the SMPU nanofibers. In addition, the results showed that the prepared electrospun nanofibrous mats have adequate mechanical and shape memory properties for practical biomedical applications. Bioactivity studies indicated that the presence of MNPs could enhance the In-vitro cell cultivation of MG63 bone cells on the nanofibers. These results indicated that the prepared electrospun nanofibers could be utilized as a potential candidate for shape memory-assisted smart wound healing applications.