Objective To review new progress of related research of peri pheral nerve defect treatment with tissue engineering in recent years. Methods Domestic and internationl l iterature concerning peri pheral nerve defect treatment with tissue engineering was reviewed and analyzed. Results Releasing neurotrophic factors with sustained release technology included molecular biology techniques, poly (lactic-co-glycol ic acid) microspheres, and polyphosphate microspheres. The mixture of neurotrophic factors and ductus was implanted to the neural tube wall which could be degraded then releasing factors slowly. Seed cells which were the major source of active ingredients played an important role in the repair and reconstruction of tissue engineering products. The neural tube of Schwann cells made long nerve repair and the quality of nerve regeneration was improved. Nerve scaffold materials included natural and synthetic biodegradable materials. Tube structure usually was adopted for nerve scaffold, which performance would affect the nerve repair effects directly. Conclusion With the further research of tissue engineering, the treatment of peripheral nerve defects with tissue engineering has made significant progress.
Objective To investigate the effect of NGF on fracture heal ing, and to study the role of BMP-2 induced osteoblast. Methods Sixty cleaned male Kunming mice (aging 6-8 weeks and weighing 23-25 g) were made fracture models in the middle of femoral shaft and randomly divided into four groups (groups A, B, C and D, n=15). Fracture was treated with NGF/ normal sal ine, BMP-2, BMP-2 /NGF/normal sal ine, and normal sal ine in groups A, B, C and D, respectively. After 14, 21 and 28 days, the specimens were selected from 5 mice each group to do the biochemical and histological analysis. Beforethe mice were killed, the arteriovenous blood was taken from their eye-ball to test the ALP activity. Results After 14 days,21 days and 28 days, the gross observation showed that the size and hardness of bone tissue, and callus tissue growth increased in groups A, B and C order and were higher than those in group D; the X-ray films showed that the calcified area increased in groups A, B and C order and were higher than those in group D; the histological observation showed that the trabecular maturity increased in groups A, B and C order and were higher than those in group D. The osteoblast area, the gray degree value of the radiographs in callus tissue, the ALP contents of serum and callus tissue, calcium content of callus tissue and net weight of callus were higher in groups A, B and C than in group D. There were significant differences (P lt; 0.05) in osteoblast area and gray degree values of the radiographs at 14, 21 and 28 days; in ALP contents of serum at 14 days; in ALP contents of callus tissue at 14 days and 21 days; in calcium content of callus tissue at 21 days and 28 days among 4 groups. There were significant differences in net weight of callus between groups B, C and groups A, D at 14 days (P lt; 0.05). At 21 days and 28 days, the trabecular surface index of osteoblast, the average trabecular volume and the mean trabecular width decreased as time went on, having an increase order of groups A, B, C and was higher in groups A, B, C than in group D, showing significant differences among 4 groups (P lt; 0.05). Conclusion NGF promotes the heal ing of fractures. NGF possesses synergistic effect on ectopic bone formation induced by BMP-2.