  Electrospun nanofibrous membranes of natural polymers, such as gelatin, are
fundamental in the design of regenerative devices. Crosslinking of electrospun
fibres from gelatin is required to prevent dissolution in water, to retain the
original nanofibre morphology after immersion in water, and to improve the
thermal and mechanical properties, although this is still challenging to
accomplish in a controlled fashion. In this study, we have investigated the
scalable manufacture and structural stability in aqueous environment of a
UV-cured nanofibrous membrane fabricated by free surface electrospinning (FSES)
of aqueous solutions containing vinylbenzylated gelatin and
poly(epsilon-caprolactone) dimethacrylate (PCL-DMA). Vinylbenzylated gelatin
was obtained via chemical functionalisation with photopolymerisable
4-vinylbenzyl chloride (4VBC) groups, so that the gelatin and PCL phase in
electrospun fibres were integrated in a covalent UV-cured co-network at the
molecular scale, rather than being simply physically mixed. UV-cured
nanofibrous membranes did not dissolve in water and showed enhanced thermal and
mechanical properties, with respect to as-spun samples, indicating the
effectiveness of the photo-crosslinking reaction. In addition, UV-cured
gelatin/PCL membranes displayed increased structural stability in water with
respect to PCL-free samples and were highly tolerated by G292 osteosarcoma
cells. These results therefore support the use of PCL DMA as hydrophobic,
biodegradable crosslinker and provide new insight on the scalable design of
water insoluble, mechanical competent gelatin membranes for healthcare
applications.
