Electrospun polyurethane/poly (ɛ-caprolactone) nanofibers promoted the attachment and growth of human endothelial cells in static and dynamic culture conditions

Abstract

In this study, the angiogenic capacity of human endothelial cells was studied after being plated on the surface of polyurethane-poly caprolactone (PU/PCL) scaffolds for 72 h. In this study, cells were designated into five different groups, including PU, PU/PCL (2:1), PU/PCL (1:1); PU/PCL (1:2); and PCL. Data revealed that the PU/PCL (2:1) composition had a higher modulus and breakpoint in comparison with the other groups (p < 0.05). Compared to the other groups, the PU/PCL scaffold with a molar ratio of 2:1 had lower the contact angle θ and higher tensile stress (p < 0.05). The mean size of the PU nanofibers was reduced after the addition of PCL (p < 0.05). Based on our data, the culture of endothelial cells on the surface of PU/PCL (2:1) did not cause nitrosative stress and cytotoxic effects under static conditions compared to cells plated on a conventional plastic surface (p > 0.05). Based on data from the static condition, we fabricated a tubular PU/PCL (2:1) construct for six-day dynamic cell culture inside loop air-lift bioreactors. Scanning electron microscopy showed the attachment of endothelial cells to the luminal surface of the PU/PCL scaffold. Cells were flattened and aligned under the culture medium flow. Immunofluorescence imaging showed the attachment of cells to the luminal surface indicated by blue nuclei on the luminal surface. These data demonstrated that the application of PU/PCL substrate could stimulate endothelial cells activity under static and dynamic conditions.