A multi-layered vascular scaffold with symmetrical structure by bi-directional gradient electrospinning.

Multi-layered scaffolds are advantageous in vascular tissue engineering, in consideration of better combination of biomechanics, biocompatibility and biodegradability than the scaffolds with single structure. In this study, a bi-directional gradient electrospinning method was developed to fabricate poly(l-lactide-co-caprolactone) (P(LLA-CL)), collagen and chitosan based tubular scaffold with multi-layered symmetrical structure. The multi-layered composite scaffold showed improved mechanical property and biocompatibility, in comparison to the blended scaffold using the same proportion of raw materials. Endothelialization on the multi-layered scaffold was accelerated owing to the bioactive surface made of pure natural materials. hSMCs growth showed the similar results because of its better biocompatibility. Additionally, fibers morphology change, pH value balance and long term mechanical support results showed that the gradient structure effectively improved biodegradability.