Facile method for covalently binding peptides onto polycaprolactone films and nanofibers

Polycaprolactone (PCL) is an inexpensive polymer used in numerous biomedical applications due to its biocompatibility and gradual biodegradation. While PCL scaffolds with diverse topographical features are well characterized, it is challenging to functionalize PCL constructs with bioactive peptides. In this study, a thiol-norbornene click chemistry was used to immobilize thiolated peptides onto PCL surfaces. PCL was mixed with varying amounts of poly(ethylene glycol) (PEG) modified with norbornene (Nor), and the presence of Nor in PCL-Nor blends was confirmed with ¹H NMR spectroscopy. These blends reduced PCL film surface roughness and had no effect on nanofiber diameter. Mesenchymal stem cells (MSCs) cultured on PCL-Nor films and nanofibers functionalized with thiolated RGD peptides adhered and adopted morphologies concomitant with the underlying surface topographies. This study shows that PCL-Nor blends can be used to form rigid PCL structures amenable to photopatterning with any thiolated molecule including bioactive peptides, thereby expanding the functionality of PCL-based biomaterials.