Immobilization of anti-CD31 antibody on electrospun poly(ɛ-caprolactone) scaffolds through hydrophobins for specific adhesion of endothelial cells.

Hydrophilicity improvement and bioactive surface design of poly(ɛ-caprolactone) (PCL) grafts are of key importance for their application in tissue engineering. Herein, we develop a convenient approach for achieving stable hydrophilic surfaces by modifying electrospun PCL grafts with a class II hydrophobin (HFBI) coating. Static water contact angles (WCA) demonstrated the conversion of the PCL grafts from hydrophobic to hydrophilic after the introduction of amphiphilic HFBI. ATR-FTIR and XPS confirmed the presence of self-assembled HFBI films on the surface of the PCL nanofibers. The biocompatibility of the HFBI-modified PCL grafts was evaluated by cell proliferation in vitro, and by arteriovenous shunt (AV shunt) experiments ex vivo. Anti-CD31 antibody, which is specific for endothelial cells (ECs), was subsequently immobilized on the HFBI-coated PCL scaffolds through protein-protein interactions. This bioactive PCL graft was found to promote the attachment and retention of endothelial cells. These results suggest that this stepwise strategy for introducing cell-specific binding molecules into PCL scaffolds may have potential for development of vascular grafts that can endothelialize rapidly in vivo.