Initiator-free photocrosslinking of electrospun biodegradable polyester fiber based tubular scaffolds and their cell affinity for vascular tissue engineering

Random copolyester of poly(ε-caprolactone-co-L-lactide) (PCLA) with a 50:50 feeding molar ratio was synthesized via the ring-opening polymerization and functionalized by the end-capping reaction with acryloyl chloride. The resulting acrylated PCLA was then fabricated into small diameter tubular scaffolds by electrospinning technique and the formed scaffolds were followed by photocrosslinking under UV irradiation in the absence of photoinitiator. The mechanical strengths including tensile, suture retention and burst pressure were greatly enhanced after the photocrosslinking. The in vitro degradation data clearly revealed that the mechanical properties of the crosslinked scaffolds still remained after one month degradation in PBS solution, while those of the non-crosslinked ones lost heavily. The cytotoxicity assay on the mouse fibroblast L929 cells was conducted via MTT measurement. Furthermore, the observation on endothelial and fibroblast cell adhesion and proliferation was also made by using scanning electron microscopy (SEM). The initiator-free photocrosslinked tubular scaffolds show the potential to be used in vascular tissue engineering.