Study On The Properties And Biocompatibility Of Electrospun Funnel Web Spider Silk

Electrospinning is one of the most important techniques for the production of nanoscale fibers. The core of the method is to make polymer melt or solution under static electric field overcome the surface tension to create a charged jet, then nanofibers solidify, finally, the nanofibers are deposited randomly on the surface of the collection plate. Because of the morphology feature of small diameter, high surface area to volume ratio and high porosity, they can be used as high porous cell-growth scaffolds for improving cellular migration and proliferation, they can also be widely used in tissue engineering and biomedical engineering areas such as vascular grafts, wound dressings and drug delivery. A balanced combination of high tensile strength, stiffness, and elasticity makes the spider silk one of the toughest, if not the toughest material of its kind known so far. Moreover the distinctive properties such as good biocompatibility and biodegradability could be exploited in the field of scaffolds for tissue engineering. Recent successes in the identification, artificial synthesis, and expression of genes coding for spider silk proteins have attracted interests in the relationships between the molecular structure and the functional behavior of spider silks.The funnel-web spider silk was collected as study object. On the basis of analysis of the spider silk properties, we studied the properties of electrospun spider silk mats, the influence of post-treatment to as-spun mats, the biosafety of as-spun mats and the properties of electrospun spider silk/ collagen mats.Funnel-web spider silk exhibited a thermal stability below 288℃. FTIR showed that in amide II and amide III, there are obvious peak ofβ-sheet, X-ray data confirmed the result.Spider silk was dissolved in HFIP. The fiber diameter of electrospun spider silk increased with the increasing of the solution feed rate, but decreased with the increasing of the distance between anode and screen; it increased firstly and decreased later with the increasing of voltage. The elelctrospun mats exhibited a thermal stability below 279.8°C. Because of the change of conformation and crystalline structure, the breaking strength and Young's modulus was much lower than reported spider silk, but the breaking strain was as much as that of spider silk.After treated by methanol, ethanol and distilled water, spun mats shrunk. The crystalline structure and mechanical properties changed.After immersing in PBS solution for 4 weeks, some thin fibers and branches of thicker fibers broke up, while the thicker fibers didn't break up. The cell biocompatibility was evaluated with porcine iliac artery endothelial cells (PIECs). The results indicated that the electrospun mats exhibited a good biocompatibility and can enhance the proliferation of cells.Preliminary research was made on the electrospun spider silk/ collagen fiber. In the condition of voltage 18kV, distance 11cm and extrusion solution rate 2.0ml/h, the fiber diameter increased when the collagen proportion of total concentration increased. The breaking strength and Young's modulus were increased gradually with the increasing content of collagen, but the breaking strain decreased.