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.

The development of responsive small molecular hydrogels that can be applied for recovery of cells postculture attract extensive interests for researchers in fields of cell biology, stem cell differentiation, and tissue engineering. We report in this study several responsive small molecular hydrogels based on adamantane–peptides whose gel to clear solution phase transition can be achieved by addition of β-cyclodextrin (β-CD) derivatives. The small molecular hydrogels are formed by our recently developed method of disulfide bond cleavage by glutathione (GSH). Mouse fibroblast 3T3 cells attach and grow well at the surface of hydrogels. Furthermore, 3T3 cells postculture can be recovered from the gels by the addition of a β-CD derivative due to formation of clear solutions by the adamantane−β-CD interaction. The culture on hydrogels and recovery process do not cause obvious effects on behaviors of 3T3 cells. The results shown in this study indicate that small molecular hydrogels based on adamantane–peptides have great potentials in research fields where further analysis of cells is needed.