Fabrication and Properties of the Electrospun Polylactide/Silk Fibroin-Gelatin Composite Tubular Scaffold

Abstract

In this study, a tubular scaffold composed of polylactide fibers (outside layer) and silk fibroin-gelatin fibers (inner layer) was fabricated successfully by electrospinning. Morphological, biomechanical, and dissolvable properties of the composite scaffolds were examined, in particular, biocompatibility of the scaffolds were evaluated in vitro and in vivo by means of cell culture and subcutaneous implantation test. The PLA/SF-gelatin tubular scaffolds, with porosity of approximately 82 +/- 2%, possessed appropriate breaking strength (2.21 +/- 0.18 MPa), pliability (60.58 +/- 1.23%), and suture retention strength (4.58 +/- 0.62 N). The burst pressure strength of the composite scaffolds reached 1596 +/- 20 mmHg, which is much greater than that of the native vessels. The composite scaffolds could hardly dissolve in the water; the water-dissolved rate was only 0.3 +/- 0.1%. MTT assay and SEM observation indicated that both 3T3 mouse fibroblasts and human umbilical vein endothelial cells could adhere, spread, and proliferate well on the composite tubular scaffolds after culturing for 14 and 21 days, respectively. The subcutaneous implantation results showed that macrophages and lymphocytes were not observed, which indicated that the composite scaffolds could induce minor inflammatory reactions in vivo. The PLA/SF-gelatin tubular scaffolds are biocompatible, possess appropriate biomechanical properties, and provide a favorable environment that supports the growth of cells, which shows that the composite tube can be considered as an ideal candidate for tissue engineering blood vessel.