Functionalization of PCL fibrous membrane with RGD peptide by a naturally occurring condensation reaction

Poly(ε-caprolactone) (PCL) is widely adopted as an ingredient for tissue engineering scaffolds. To improve its cell affinity, in this study, we developed a new method to introduce bioactive RGD peptides onto the surface of PCL via condensation reaction between 2-cyanobenzothiazole (CBT) and D-cysteine. The PCL fibrous membranes were prepared by electrospinning, and RGD functionalization was characterized by fluorescence microscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA). As expected, our results demonstrated the successful RGD immobilization on the surface of PCL. RGD modification improved the hydrophilicity of PCL, changing their WCA from 112.20° to 38.35°. Cell adhesion, spreading and proliferation of 3T3 fibroblasts were also enhanced. We therefore believe that the methods reported in this study was facile and effective for functional modification of the hydrophobic PCL scaffolds. The moderate reaction conditions are also suitable for covalent immobilization of bioactive molecules onto PCL.