Preparation and property of complicated controlled release drug of nerve growth factor

Objective: To prepare the complicated controlled release drug vehicles of nerve growth factor（NGF）,and make experiments in vitro and in vivo in order to confirm whether it becomes drug vehicle of NGF. Methods: The microspheres of NGF were prepared drug microsphere technology and fixed with the fibrin gels to make the controlled release drug of NGF.In vitro,the drug release curve and bioactivity of complicated controlled release drug of NGF were made.In vivo,the 18 Wister rats were randomly divided into three groups: acellular nerve allograft + the complicated controlled release NGF（A group）,acellular nerve allograft（group B） and acellular nerve allograft + fibrin glue（group C）.The animals were killed and the nerve regeneration lengths were measured in two weeks after operation. Results: The NGF was detected from the complicated controlled release drug of NGF at least 60 days and the bioactivity of released NGF stimulated the neuritis growth of chick dorsal root ganglion.In two weeks after operation,the axonal regeneration lengths were measured: A group was 7.46±1.75mm,B group was 4.62±1.06mm and C group was 4.36±1.20mm respectively.The lengths in A group were greater than those in B and C group（P＜0.05）. Conclusion: The complicated controlled release drug of NGF can release NGF for long time and protect the bioactivity of NGF.The method is good way to supply the exogenous NGF to improve the regeneration of nerve.