关键词: 热塑性聚氨酯(TPU), 硼硅酸盐生物活性玻璃(SeBSG), 静电纺丝, 体外生物活性, 生物相容性

Abstract: Currently, due to the enormous annual market demand for bone repair and replacement materials that enable rapid recovery from hard tissue injury diseases, it is highly necessary to develop biomaterials with certain bioactivity for bone defect repair, replacement, and even regeneration. In the field of bone tissue engineering, thermoplastic polyurethane (TPU) is a synthetic polymer that is considered one of the most promising biopolymers due to its exceptional mechanical properties and excellent biocompatibility. However, the application of TPU in bone tissue engineering is limited by its insufficient bioactivity and ability to induce the proliferation and differentiation of related osteoblasts. Borosilicate bioglass has attracted widespread attention from researchers due to its complete degradability after implantation and its easier complete conversion into hydroxyapatite. At the same time, the addition of trace element Se can further enhance the material’s properties and collectively promote tissue repair.
In this study, TPU-SeBSG bone repair composites were prepared using electrospinning technology with thermoplastic polyurethane (TPU) and borosilicate bioactive glass (SeBSG) as raw materials. The effects of doping with different mass fractions of borosilicate bioactive glass on the micromorphology and chemical structure of the composites were investigated using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Subsequently, the physicochemical properties, in vitro antibacterial properties, in vitro bioactivity and biocompatibility of TPU-SeBSG composite fiber membranes were examined, and the influence of different SeBSG doping amounts on the physicochemical properties and in vitro biological properties of TPU-SeBSG composite fiber membranes was analyzed.
The results indicated that as the doping amount of SeBSG in TPU-SeBSG increased, the fiber diameter first increased and then decreased, and the distribution of fiber diameters became more uneven. Infrared spectrogram and elemental map verified that SeBSG was successfully loaded onto the fiber membranes, and the presence of SeBSG did not undergo a chemical reaction with TPU to modify its chemical structure. In terms of physicochemical properties, the TPU-SeBSG composite fiber membranes exhibited high porosity, and the hydrophilic property of the composite fiber membrane was optimal when the mass fraction of SeBSG reached 3%. The mechanical tensile properties of the TPU-SeBSG composite fiber membranes decreased with the addition of SeBSG, but the minimum elongation at break could be maintained above 300%. In terms of in vitro biological properties, the TPU-SeBSG composite fiber membranes exhibited significant antibacterial activity against Staphylococcus aureus, as well as excellent in vitro bioactivity and good in vitro biocompatibility. Based on the above experimental conclusions, it can be inferred that the TPU-SeBSG composite fiber membranes exhibit the best overall performance when the mass fraction of SeBSG reaches 3%, indicating its good application prospects in the field of bone tissue engineering in biomedicine.

Key words: thermoplastic polyurethane (TPU), borosilicate bioactive glass (SeBSG), electrospinning, in vitro bioactivity, biocompatibility