The work was intended to explore the effect of the widely available cationic polymer polyethylenimine (PEI) on small diameter poly(ɛ-caprolactone) (PCL) blood vessel grafts. PEI was blended with PCL and electrospun into nanofibrous vascular scaffolds. The morphologies, wettabilities, mechanical properties, and biological activities of the PCL/PEI electrospun nanofibers were investigated. It was found that by increasing the content of PEI to 5% within the scaffolds, the fiber diameters decreased from 469.7 ± 212.1 to 282.5 ± 107.1 nm, the water contact angle was reduced from 126.6 ± 1.1° to 27.6 ± 3.9°, while the Young's modulus increased from 2.0 ± 0.2 to 4.1 ± 0.1 MPa, the suture retention strength increased from 4.2 ± 0.4 to 6.1 ± 0.7 N, and the burst pressure increased from 801.2 ± 14.1 to 926.2 ± 22.8 mmHg. The in vitro evaluations demonstrated that the nanofibers containing 2% PEI promoted the attachment and proliferation of human umbilical vein endothelial cells (HUVECs).
