Protective effect of brain-derived neurotrophic factor-PLGA sustained release microspheres on peripheral nerve injury / 第二军医大学学报

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(30 0g/mL , 1 mL/kg) was injected into the local nerve injury sites for BDNF group and BDNF-PLGA sustained release microspheres (BDNF 30 0g/mL , 1 mL/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 4 weeks 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 P$0. 01) , and the improvements were also significantly greater than those in group BDNF (P$0. 05). The BDNF-PLGA sustained release microspheres also significantly improved the pathology changes oi sciatic nerve injury, including those oi the myelin sheath, axon and vacuole. Conclusion The BDNF- PLGA sustained release microspheres have prominent protective effect against the peripheral nerve injury in rats.