Study On Fabrication Of Silk/PLGA Artificial Blood Vessel Through Electrospinning

Electrospinning is one of the most convenient ways that can produce nanoscale or microscale fibers directly and continuously. 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. Using a novel collection tube rotating and shifting horizontally make a artificial blood vessel with nanoscale or microscale pore structure available.A preliminary research on the artificial blood vessel was made though electrospinning silk and poly(lactide-co-glycolide acid). The author researched the influence of the concentration, voltage, electrospinning distance between syringe and collecting tube on fibers'morphology and structure. The Aggregation structure was tested by means of IR, DTA-TG and XRD. The difference of aggregation structure of silk, PLGA and silk/PLGA tube and the difference between aligned and non-aligned fiber tube was tested. The author studied the mechanics, resolving properties and porosity of the formed vessel, and discussed the effect of the fiber orientation to the intensity and extensibility. Plasma processing was taken to graft with heparin to improve the anticoagulant property.The results show that: Along with the concentration of the spinning solution decreasing, fibers'diameter is reduced. The voltage and the electrode distance are the secondary factors influencing the feature of the material and the diameter was decreased with the increasing voltage at same electric field intensity. The main structure of molecular aggregation of Silk /PLGA is random coil, and someβ-sheet is appeared. There is not any new chemical bond formed between silk protein and PLGA. Fiber diameter and wall thickness of the blood vessel have little influence to the porosity. The rotating speed and the velocity of horizontal shift can improve the orientation of the fiber axially or circumferentially. The vessel with fiber axially orientated has the best insensibility while the one with fiber circumferentially orientated has better extensibility. Ethanol treating improves the intensity but reduce the extensibility. Plasma processing is a feasible way to improve anticoagulant property. After processing on the condition of 30W and treating 5-6min, the grafting rate is 155μg/g, and APTT reach 43.3s, and the anticoagulant property is improved.