Siatic nerve regeneration in rats stimulated by fibrin glue containing nerve growth factor: an experimental study.

OBJECTIVE: To study the effects of fibrin sealant containing nerve growth factor on the peripheral nerve regeneration. STUDY DESIGN: A four-group experimental design with repeated measures on one factor was used. METHODS: Fibrin glue (FG) containing NGF was injected into the site of end-and-end sutured peripheral nerve (sciatic nerve) (group I: NGF+FG), meanwhile three control groups were set-up: group II (NGF), group III (FG), and group IV (normal saline). Observation to the function and morphology of the sciatic nerve was carried out at the end of 4, 8, 12 weeks postoperation. Data were analyzed using ANOVA, with the appropriate post hoc between-groups comparison test. RESULTS: Electrophysiological testing. The NAP and NCV of group I (NGF+FG) were greater than those of group II (NGF), group III (FG), or group IV (normal saline) (p<0.05). Sciatic functional index (SFI). It began to ameliorate at 4 weeks postoperation and SFI increased as time went on. And the SFI in group I (NGF+FG) was better than those in group II (NGF), group III (FG), or group IV (normal saline) (p<0.05). Morphology. In the MGF-stained sections, dissociated myelin debris was less and regenerated nerve fibres were in larger quantities in group I (NGF+FG) than in other groups. In the HE-stained sections, regenerated nerve fibres distal to anastomosis significantly increased, and axon and myelin had a clearer outline in group I (NGF+FG) than in other groups. Electron microscopy indicated that the regenerated nerve fibres were more mature and the development of the axons was greater in group I than in other control groups. CONCLUSIONS: FG can be used as carrier of exogenous NGF, and they can provide synergistic effects for the peripheral nerve regeneration after the integration of the two.

[Influence of sterilization treatments on continuous carbon-fiber reinforced polyolefin composite].

OBJECTIVE: To evaluate the influence of sterilization treatment on continuous carbon-fiber reinforced polyolefin composite (CFRP) so as to provide experimental reference for selection of sterilization method for CFRP. METHODS: Seventy bars of CFRP were divided into 7 equal groups to undergo sterilization by autoclave, 2% glutaraldehyde soaking, 75% alcohol soaking, ethylene oxide sterilization, and Co-60 gamma ray irradiation of the dosages 11 kGy, 25 kGy, and 18 kGy respectively, and another 10 bars were used as blank controls. Then the bars underwent three-point bending test and longitudinal compression test so as to measure the biomechanical changes after sterilization treatment, including the maximum load, ultimate strength, and elastic modulus. RESULTS: Three-point bending test showed that the levels of maximum load of the all experimental groups were lower than that of the control group, however, only those of the 3 Co-60 irradiation groups were significantly lower than that of the control group and that Co-60 radiation lowered the level of maximum load dose-dependently; and that the levels of ultimate strength of all the all experimental groups were lower than that of the control group, however, only those of the 3 Co-60 groups were significantly lower than that of the control group and that the higher the dosage of Co-60 radiation the lower the level of ultimate strength, however, not dose-dependently. The elastic modulus of the Co-60 25 KGy group was significantly higher than that of the control group, and there was no significant difference in the level of ultimate strength among the other groups. Longitudinal compression test showed that the levels of maximum load and ultimate strength of the 3 Co-60 irradiation groups, autoclave group, and circular ethylene groups were significantly lower than that of the control group, and there was no significant difference in elastic modulus among different groups. CONCLUSION: During sterilized package of CFRP products produced in quantity autoclave sterilization and Co-60 gamma ray irradiation sterilization should be avoided. Ethylene oxide is proposed as the best sterilization method. If gamma ray irradiation is to be used further technology improvement is necessary.