Influences of tensile load on in vitro degradation of an electrospun poly(L-lactide-co-glycolide) scaffold

Scaffolds for tissue engineering and regenerative medicine are usually subjected to different mechanical loads during in vitro and in vivo degradation. In this study, the in vitro degradation process of electrospun poly(L-lactide-co-glycolide) (PLGA) scaffolds was examined under continuous tensile load and compared with that under no load. As PLGA degraded in phosphate-buffered saline solution (pH 7.4) at 37°C over a 7-week period, the tensile elastic modulus and ultimate strength of the loaded specimen increased dramatically, followed by a decrease, which was much faster than that of the unloaded specimen, whereas break elongation of the loaded samples declined more quickly over the whole degradation period. Moreover, molecular weight, thermal properties and lactic acid release showed greater degradation under load. Also, a ruptured morphology was more obvious after degradation under tensile load. The results demonstrate that tensile load increased the degradation rate of electrospun PLGA and it may be necessary to consider the effects of mechanical load when designing or applying biodegradable scaffolds. Finally, some possible explanation for the faster degradation under load is given.