Study On Electrospinning Of Regenerated Silk Fibroin/Gelatin

Electrospinning is the most basic technique for the production of nanoscale fibers. It could produce polymer nanofibers directly and continuously. Under high voltage and static electric field, a charged jet is created from a polymer melt or solution, then the solvent evaporates and nanofibers solidify. The nanofibers are deposited randomly on the surface of the collection plate in the form of non-woven nanofiber membranes. Because nanofibers have several useful properties including small diameter,high surface area to volume ratio and high porosity, they can be used in tissue engineering and biomedical engineering extensively.This thesis made a preliminary research on the electrospinning of regenerated silk fibroin (SF)/Gelatin by the self-designed electrostatic spinning instrument, making use of good biodegradability of gelatin and characteristic of share-solvent, formic acid as solvent. The author researched the influence of the quality ratio of SF/Gelatin, concentration, voltage, electrospinning distance on fibers'morphology and structure. The influence of concentration,voltage and ethanol treating on microstructure of electrospun SF/Gelatin nanofibers was also tested and analyzed by means of IR and DTA-TG. Moreover, The author studied the mechanics,resolving properties,pore diameter and porosity of SF/Gelatin blended membrane. Finally, To assay the cytocompatibility and cell behavior onto the electrospun SF/Gelatin nanofibers and electrospun SF nanofibers, cell morphology and proliferation was examined by microscope,dyeing micrograph,MTT and scanning electron microscopy(SEM).The results showed that: Along with the concentrations of spinning solution decreasing and the electrode distance increasing, fibers'diameter was reduced. The diameter was decreased with the increasing voltage at same electric field intensity. Under the technical parameters of 11wt% SF/Gelatin (70/30) spinning solution,electrode distance 13cm,voltage 22kv,the electrospun nanofibers had narrower diameter distributions and diameter reached 83.9nm. For the H-bond was formed between the molecule of SF and Gelatin, the content ofβ-sheet of SF in electrospun SF/Gelatin nanofibers became more. Along with the concentrations of spinning solution increasing and ethanol treating, the content ofβ-sheet of SF in electrospun SF/Gelatin nanofibers was increased, and the water-dissolved rate declined,the intensity and initial capacity of electrospun SF/Gelatin nanofibers were enhanced. Along with the ratio of Gelatin increasing, the water-dissolved rate was increased,the intensity and initial capacity of electrospun SF/Gelatin nanofibers were enhanced. Along with the concentrations of spinning solution increasing, the aperture diameter of electrospun SF/Gelatin nanofibers was decreased and the porosity was increased; both the pore diameter and porosity were increased by the thickness of electrospun SF/Gelatin nanofibers scaffold increasing. Blending with Gelatin, the SF/Gelatin nanofibers scaffold may be a good candidate for both mouse fibroblasts and human umbilic vein endothelium cells spreading and proliferating.