Crosslinking of poly(L-lactide) nanofibers with triallyl isocyanutrate by gamma-irradiation for tissue engineering application

The radiation crosslinked poly(L-lactide) (PLLA) electrospun nanofibers have been developed with improved thermal stability and mechanical properties. Trially isocyanurate (TAIC) were added into PLLA solution at different weight ratios (1, 3, and 5%) and electrospun into nanofibrous mats, the mats were then irradiated by gamma ray at different radiation doses (5, 10, and 25 kGy) to crosslink the PLLA chains. Their surface morphology, thermal properties, mechanical properties, and biodegradation properties were investigated and compared before and after gamma irradiation. Furthermore, the in vitro biocompatibilities were also evaluated by using mouse L929 fibroblasts. The results indicated that the efficient crosslinking networks can be generated when the TAIC content is higher than 3%. The thermal stability and tensile mechanical properties were significantly increased at higher irradiation dose of 10 and 25 kGy. However, radiation dose at 25 kGy have an adverse effect on the thermal stability of crosslinked samples due to thermal degradation induced by irradiation, the crosslinked samples irradiated at 10 kGy exhibited the best enzymatic degradation. The in vitro results also revealed that the crosslinked PLLA/TAIC composite nanofibers did not induce cytotoxic effects and are suitable for cell growth. Therefore, the crosslinked PLLA nanofibers are one of the promising materials for future tissue engineering applications.