Fabrication and optimization of bioactive cylindrical scaffold prepared by electrospinning for vascular tissue engineering

Vascular regeneration is strictly depended on the proliferation and spreading of the injured endothelial cell layer especially in the small diameter vessels. If a substrate is optimized for this application, there will be new hopes to control the vascular wall thickness. Herein, the various strategies including the surface modification, co-electrospinning and blend-electrospinning methods were employed to prepare the nanofibrous scaffolds from polyurethane (PU), gelatin and somatotropin. These protein biomolecules could support the endothelial cell attachment and also their proliferation, respectively. The assays including the scaffold fibers and cell morphologies, mechanical tensile behavior, surface wettability, the cell proliferation and the release kinetic profile confirmed the higher bioactivity of the scaffold which was fabricated by a blend of PU, gelatin and somatotropin agents. This group represented better cell spreading and cell attachment in spite of lower mechanical properties compared to the co-electrospun groups. Regarding this issue, the kinetic model for the release of somatotropin growth factor was an anomalous non-Fickian diffusion due to the impact of polymer relaxation and erosion on the somatotropin release. As a whole, by incorporation of somatotropin in the PU fibers, a sustained release pattern resulted. This controlled release manner of somatotropin enhanced the endothelial cell proliferation that is required for the therapeutic goal of the damaged vessels. Graphic abstract