| The SF/PBS ultrafine composite fibrous membranes of different structures were fabricated by the blend, hybrid and coaxial electrospinning in order to synchronously enhance the mechanical property of SF, and also obtain SF/PBS composite tissue engineering scaffolds, which possess a better cytocompatibility depending on biological evaluation, and finally further extend the application range of SF in biomaterials.To prepare SF/PBS ultrafine composite fibrous membranes, the parameters in electrospinning PBS process were studied. the morphology of the received electrospun PBS ultrafine fibers is better, when the mass fraction of 6%, electric field strength 1.5kv/cm (spinning voltage of 18kv, spinning distance of 12cm) and spinning flow rate of 0.01ml/min. Comparison with the PBS cast membrane, the crystallinity of electrospun PBS ultrafine fibrous membranes decreases, the tensile failure strength slightly decreases to 18.6MPa, but failure elongation is almost the double of cast membranes up to 120%.The SF/PBS ultrafine composite fibrous membranes of different structure are prepared by the blend and hybrid electrospinning, and the morphology, structure and mechanical properties are also studied before and after treatment of methanol. Coaxial electrospinning of PBS (core layer) and SF (shell layer) was also further studied. The morphology, structure and mechanical properties of PBS/SF core/shell ultrafine fibrous membrane were also tested. Finally, Cell biocompatibility was evaluated on different SF/PBS ultrafine composite fibrous scaffolds prepared by the blend, hybrid and coaxial electrospinning. The main results of this work are summarized as follow:(1) After treatment with methanol, the crystallization properties of electrospun SF/PBS blend ultrafine composite fibrous membranes gradually becomes better with addition of PBS, and the crystallization properties on the ultrafine composite fibous membranes with same mass ratio is better. The tensile strength first decreases and then increases with addition of PBS, and failure strain gradually increases. For the same blend mass ratio, failure strength increases, but failure strain decreases. When the blend ratio is 50/50, failure strength is close to 16MPa and failure strain is up to 50%, so mechanical properties of SF/PBS blend ultrafine fibrous membranes was improved.(2) The crystallization properties of the whole hybrid composite ultrafine fibrous membranes treated with methanol also increase with addition of PBS, and the crystallization properties on the same hybrid mass ratio is better than that before treatment. in addition, the tensile strength gradually increases with addition of PBS, and also failure strain gradually increases. For the same hybrid mass ratio, tensile strength increase, but failure strain decreases. When the hybrid mass ratio is 50/50, mechanical properties of SF/PBS hybrid ultrafine fibrous membrane was best, failure strength was up to 17.3MPa and failure strain was 38.2%.(3) The PBS/SF core/shell ultrafine fibers was successfully prepared by coaxial electrospinning, After treatment with methanol, due to the increasing of shell thickness, absorption intensity of X-ray diffraction in core PBS decreases, which lead to the whole crystallization properties of PBS/SF core/shell ultrafine fibrous membranes dropped. Compared with non-treatment, the electrospun PBS/SF core/shell ultrafine fibrous membrane tensile strength increased from 14.9MPa to 17.2MPa, but the failure strain decreased from 96.8% to 81.8 %.(4) Through L929 cell adhesion experiment, it was found that the blend, hybrid, and core-shell ultrafine composite fibrous scaffolds do not have significant difference. However, for proliferation experiment, they have certain advantages, especially scaffolds of blend mass ratio 50/50 and core/shell scaffolds show more obvious advantages, their OD values are higher than that of SF, and the mechanical properties are better, so we can see that these scaffolds have great application potential in tissue engineering scaffolds. |
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