| Electrospinning technology could be used for preparing fibers with average diameter ranged from micron to several hundred nanometers. The electrospun membranes could essentially mimick the topographic morphology of extracellular matrix (ECM). In addition, small-diameter vascular graft could be conveniently fabricated by collecting the fibers on the rotating drum.In this study, coaxial electrospinning was adopted to prepare core-shell fibrous tubes. Poly(s-caprolactone) (PCL) was used as the core material to enhance the mechanical strength of the tubes. Gelatin formed the shell structure of the fibers to improve cell adhesion and proliferation.The mechanical properties of vascular grafts with inner diameter of 3.5 mm were studied. It was found that the grafts with high PCL content had largest fiber diameters, porosity and pore size, and also displayed higher tensile strength, suture retention strength. However, the complicance of the grafts was relatively poor. Compared with natural blood vessels, the electrospun tubes dispalyed comparable mechanical properties.Glutaraldehyde used for crosslinking gelatin has high cytotoxicity. To overcome the disadvantages, two mild cross-linking methods were explored in these studies, including thiol-ene photocrosslinking and utilizing Procyanidins as a crosslinker. Gelatin was first modified with methacrylic anhydride and photocrosslinked in the presence of Pentaerythritol tetrakis(2-mercaptoacetate). It was found that the introduction of the thiol reagent can improve the crosslinking degree of the gelatin fiber, but the mechanical strength of the fibrous membranes was still poor. As a result, Procyanidins was introduced as a novel crosslinker. The effect of temperature, crosslinking time and concentration of the procyanidins on the crosslinking extent was studied. It was found that the optimized conditions are 40℃,4 days and 5%. The as-prepared fibrous membranes have similar mechanical properties to those crosslinked with glutaraldehyde.
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