Preparation and characterization of silk fibroin/polyvinyl alcohol nanofibers containing VEGF

Aim and Background: Silk fibroin (SF) and polyvinyl alcohol (PVA) nanofibers preserve drugs bioactivity. The vascular endothelial growth factor (VEGF) stimulates cell proliferation and inhibits cell death. Methods: : 1)Using Na2CO3 and LiBr, SF was extracted. 2)SF nanoparticles were prepared using a solution of silk and acetone with a ratio of 1:4. After centrifuging it, replace the supernatant with deionized water. The solution was frozen and transferred to a freeze-dryer. 3) To prepare top and bottom layer solutions, PVA (10% w/v), SF (3.5% w/v), and VEGF (10% w/v) were dissolved in deionized water. To prepare the solution of the middle layer, PVA (10% wt/vol), SF (3.5% wt/vol), and SF nanoparticles (0.5% wt/vol) were dissolved in water. The electrospinning conditions were optimized, including 15 cm as the needle-collector distance, 0.4 mL/h as the flow rate, and 15 kV as voltage. Results and discussion: Figure 1 shows the results of the tests. The average fiber diameter calculated with ImageJ software was 289 ± 2.62 (a). The prepared scaffold absorbed water well. (b). The cell adhesion test on the samples shows that the cells on the scaffold containing VEGF have a greater tendency to anchor and connect. Research has shown that increasing the amount of VEGF increases the cell surface (c,d). Conclusion: SF/PVA-based scaffolds containing VEGF were successfully synthesized. This scaffold gave them proper water absorption and cell adhesion.