Effect of Post-Treatment on Mechanical and Biological Properties of Coaxial Electrospun Core–Shell Structured Poly(lactic-co-glycolic acid)/Gelatin Methacrylamide Fibrous Scaffolds

Although electrospun vascular scaffolds are becoming a center of artificial blood vessel scaffold research because of their ability to promote organizational reconstruction, the mechanical and biological properties of initial electrospun scaffolds are relatively insufficient. The poor mechanical properties of electrospun scaffolds are mostly attributed to their high porosity and weak bonding at fiber junctions. To further improve these properties, they were post-treated by heat treatment, crosslinking, and solvent-vapor welding. In this study, coaxial electrospun poly (lactic-co-glycolic acid) (PLGA)/gelatin methacrylamide (GelMA) composite scaffolds were developed with PLGA and heparin as the core component and GelMA as the shell component. Then, the PLGA/GelMA (P/G) scaffolds were post-treated by four methods, which were crosslinked in deionized water (P/G-CDI), crosslinked in GelMA solution (P/G-CG), heating annealing (P/G-HA), and solvent-vapor annealing (P/G-SA). Compared to the P/G scaffold, the fibers of the electrospun scaffolds after post-treatment were bonded, and the porosity and degradation rate were reduced. The P/G-CG scaffold exhibited optimized mechanical properties and bioactivities. After immersing the P/G scaffold in GelMA solution and UV crosslinking, the tensile strength of the P/G-CG scaffold was greatly improved by 2.5 times compared to that of the P/G scaffold. Moreover, the P/G-CG scaffold supported the adhesion and proliferation of human umbilical vein endothelial cells (HUVECs) better than the P/G, P/G-CDI, and P/G-HA scaffolds. Overall, the results suggest that the modified P/G-CG scaffold possesses better performance in vascular application.