Sustained release of VEGF by coaxial electrospun dextran/PLGA fibrous membranes in vascular tissue engineering

VEGF-loaded core/shell fibrous membranes were prepared by coaxial electrospinning with dextran (DEX) as the core component and poly(lactide-co-glycolide) (PLGA) as the shell polymer, respectively. The electrospun DEX/PLGA fibers were observed by scanning electron microscopy, transmission electron microscopy and confocal microscopy to identify the core/shell fiber structure and the protein distribution. The results of tensile tests showed that the DEX/PLGA membranes possessed lower tensile strength and higher Young's modulus than PLGA one. The release profiles demonstrated that vascular endothelial growth factor (VEGF) release sustained for more than 28 days. Studies on cell viability and spreading demonstrated that the DEX(VEGF)/PLGA membranes positively promoted cell proliferation and cell-membrane interaction, which further testified that the processed VEGF remained bioactivities. Furthermore, the detections for the up-regulation of intercellular adhesion molecular-1 and the release of von Willebrand factor under pathological stimuli, which are related to inflammation process and thrombus formation, exhibited a normal immune response for the DEX(VEGF)/PLGA membrane. These data suggested that the VEGF-loaded fibers could be feasible in vascular tissue engineering.