Basic fibroblast growth factor promotes nerve regeneration in a C- -ion-implanted silicon chamber

Control-released basic fibroblast growth factor-loaded poly-lactic-co-glycolic acid microspheres promote sciatic nerve regeneration in rats

Although peripheral nerve injury may result in a loss of function in innervated areas, the most effective method for nerve regeneration remains to be determined. The aim of the present study was to investigate the effect of control-released basic fibroblast growth factor (bFGF)-loaded poly-lactic-co-glycolic acid (PLGA) microspheres on sciatic nerve regeneration following injury in rats. bFGF-PLGA microspheres were prepared and their characteristics were evaluated. The sciatic nerve was segmentally resected to create a 10 mm defect in 36 Sprague Dawley (SD) rats and, following the anastomosis of the nerve ends with a silicone tube, bFGF-PLGA microspheres, free bFGF or PBS were injected into the tube (n=12 in each group). The outcome of nerve regeneration was evaluated using the sciatic function index (SFI), electrophysiological test and histological staining at 6 weeks and 12 weeks post-surgery. The bFGF-PLGA microspheres were successfully synthesized with an encapsulation efficiency of 66.43%. The recovery of SFI and electrophysiological values were significantly greater (P<0.05), and morphological and histological observations were significantly greater (P<0.05) in bFGF-PLGA microspheres and bFGF groups compared with those in the PBS group, and the quickest recovery was observed in the bFGF-PLGA microspheres group. In conclusion, the bFGF-PLGA microspheres may promote nerve regeneration and functional recovery in the sciatic nerve, and may have potential therapeutic applications in peripheral nerve regeneration.

The development of a normalization method for comparing nerve regeneration effectiveness among different graft types

The inability to compare directly different nerve grafts has been a significant factor hindering the advance of nerve graft development. Due to the abundance of variables that exist in nerve graft construction and multiple assessment types, there has been limited success in comparing nerve graft effectiveness among experiments. Using mathematical techniques on nerve conduction velocity (NCV) autograft data, a normalization function was empirically derived that normalizes differences in gap lengths. Further analysis allowed for the development of the relative regeneration ratio (RRR). The RRR function allows researchers to directly compare nerve graft results based on the NCV data from their respective studies as long as the data was collected at the same post-operation time. This function also allows for comparisons between grafts tested at different gap lengths. Initial testing of this RRR function provided confidence that the function is accurate for a continuum of gap lengths and different nerve graft types.

Development of a novel method for decellularizing a nerve graft using a hypertonic sodium chloride solution

PURPOSE

Acellular nerves are a reconstruction material and provide scaffolds for nerve regeneration. Numerous methods to develop acellular nerves have been described. However, these methods pose problems that can be attributed to incomplete acellular processing and destruction of the extracellular matrix (ECM); the former may lead to rejection response, while the latter may damage the scaffold. In order to overcome problems associated with the above-mentioned methods, we developed a novel method that employs a hypertonic sodium chloride solution to decellularize nerve graft material.

METHODS

Rat sciatic nerves were harvested, dipped in hypertonic sodium chloride solution (1 M), and shaken for 24 h. We then washed the nerves in phosphate-buffered saline for 7 days with shaking and evaluated the acellular nerves by hematoxylin-eosin (H-E) staining, immunostaining, and electron microscopy. We then transplanted the grafts to the sciatic nerve of another rat and evaluated the outcomes by H-E staining, immunostaining (anti-neurofilament antibody, anti-S-100 antibody), anterograde nerve tracing, and electron microscopy.

RESULTS

We found that our method successfully decellularized the grafts, but was mild enough to leave the ECM intact. Two months after transplantation, immunostaining and anterograde nerve tracing confirmed that Schwann cells infiltrated the grafts and induced neurofilament extension.

CONCLUSIONS

Our methodology preserves the ECM, is simple to develop, and does not involve substances that harm biogenic tissue. Acellular nerve tissue processed in this way could become a substitute material for bridging nerve gaps. Our method could also aid in the development of other acellular tissues.

Impact of Weikang Shuning Decoction on cytokines involved in the development of gastric precancerous lesions in rats with chronic atrophic gastritis

AIM: To investigate the impact of Weikang Shuning Decoction on cytokines involved in the development of gastric precancerous lesions in rats with chronic atrophic gastritis.

METHODS: Sixty Wistar rats were randomly divided into four groups, namely, normal control group, model control group, Vitacoenzyme group and Weikang Shuning decoction group. A rat model of gastric precancerous lesions was created by administration of N-methyl-N-nitroso-N-nitrosoguanidine (MNNG) via drinking water. After the rats were treated with Vitacoenzyme and Weikang Shuning Decoction for 12 weeks, respectively, the levels of serum EGF, TGF-α, GH, TNF-α, IGF-II and bFGF were determined by radioimmunoassay (RIA).

RESULTS: The levels of serum GH, TNF-α and IGF-II in the Weikang Shuning Decoction group were significantly higher that those in the model control group (0.24 ± 0.10 µg/L vs 0.11 ± 0.04 µg/L, 91.46 ± 7.63 µg/L vs 83.64 ± 3.75 µg/L and 0.38 ± 0.12 µg/L vs 0.27 ± 0.17 µg/L, respectively, P < 0.05 or 0.01). In contrast, the levels of serum EGF, TGF-α and bFGF in the Weikang Shuning Decoction group were significantly lower than those in the model control group (0.40 ± 0.11 µg/L vs 0.56 ± 0.15 µg/L, 0.021 ± 0.006 µg/L vs 0.029 ± 0.012 µg/L and 1.44 ± 0.37 µg/L vs 3.26 ± 0.45 µg/L, respectively; P < 0.05 or 0.01).

CONCLUSION: Weikang Shuning Decoction has a good therapeutic effect against gastric precancerous lesions in rats, and its efficacy is superior to that of Vitacoenzyme. Regulation of serum EGF, TGF-α, GH, TNF-α, IGF-II and bFGF levels may be one of the mechanisms underlying the therapeutic effect of Weikang Shuning Decoction against gastric precancerous lesions.