Protective effect of brain-derived neurotrophic factor-PLGA sustained release microspheres on peripheral nerve injury

Abstract

Objective To observe the protective effect of brain-derived neurotrophic factor-polylactic-co-glycolic acid(BDNF-PLGA)sustained release microspheres on the peripheral nerve injury of rats. Methods BDNF loaded PLGA microspheres were prepared by double emulsion solvent evolution method.A total of 48 adult SD rats were divided into sham operation group,model group,BDNF group and BDNF-PLGA sustained release microspheres group(n=12);the model of sciatic nerve ring clamp injury was established in the latter three groups.After operation BDNF(30μg/mL,1 mL/kg)was injected into the local nerve injury sites for BDNF group and BDNF-PLGA sustained release microspheres(BDNF 30μg/mL,1mL/kg)were injected for BDNF-PLGA group,once a week for four weeks.The general status,pace,and joint motion of each group were observed after operation;and the changes of neurological scores,nerve conduction velocity(NCV),amplitude,latency period,compound muscle action potential(CMAP)and histopathology were observed 4weeks after operation.Results The general status,pace,and joint motion of the sciatic nerve injury in BDNF-PLGA group were significantly improved compared with the model group and BDNF group.The BDNF-PLGA sustained release microspheres effectively improved the functions of injured peripheral nerve,which basically restored the normal level after four weeks,and the recovery was rapid than the BDNF group.The NCV,amplitude and latency period,CMAP amplitude,and recovery rate of CMAP in the BDNF-PLGA group was significantly improved compared with the model group(all P0.01),and the improvements were also significantly greater than those in group BDNF(P0.05).The BDNF-PLGA sustained release microspheres also significantly improved the pathology changes of sciatic nerve injury,including those of the myelin sheath,axon and vacuole.Conclusion The BDNFPLGA sustained release microspheres have prominent protective effect against the peripheral nerve injury in rats.