Biomimetic VEGF-loaded bilayer scaffold fabricated by 3D printing and electrospinning techniques for skin regeneration

Abstract

Among the fabrication methods, 3D printing due to excellent accuracy, reproducibility and customizability as well as electrospinning due to the ability to mimic the extracellular matrix structure have received many attentions. Herein, we used the combination of both mentioned techniques to produce a biomimetic bilayer scaffold for skin tissue regeneration. The upper layer of the scaffold was made of 3D printed dextran-vascular endothelial growth factor (Dex-VEGF) to stimulate angiogenesis and cell migration, and the bottom layer was made of electrospun gelatin-keratin (Gel-Kr) nanofibers to induce cell attachment. The tensile strength and elastic modulus of the scaffolds were measured in the range of 0.26 - 0.33 MPa and 5.8 - 7.2 MPa, respectively. The investigations revealed that the release of VEGF lasted up to 7 days. The bilayer VEGF-loaded scaffold demonstrated the best cellular behaviour. Chicken chorioallantoic membrane (CAM) assay confirmed the highest angiogenic potential in the presence of the bilayer VEGF-loaded scaffold. Also, based on in vivo animal studies and histopathological and immunohistochemical examinations, the highest wound healing rate was related to the bilayer VEGF-loaded scaffold within 14 days. The obtained promising results introduce the prepared bilayer scaffold as a perfect construct to accelerate wound healing.