Fig. 4

Quantification of nerve regeneration distal to the axotomy site. Axon count, mean diameter, and myelin thickness parameters for all groups were analyzed with one-way ANOVA with Holm-Sidak multiple comparison test used for p value output. The data are presented as mean ± standard error of the mean (SEM). p values reported above for interventional groups were based on comparison with the hydrogel control group. The results of hydrogel group itself were compared to those of silicone tube control group (*=0.005<p value<0.05, **= 0.0005<p value<0.005, ***= 0.0001<p value<0.0005, ****=p value<0.0001). Increased axon count was noticeable both in NH2-GO (p value= 0.0252) and Fr + NH2-GO (p value=0.0008) groups. Axon diameter was also significantly increased in these groups and reaching similar levels to normal in Fr + NH2-GO group. Moreover, the use of hydrogel improved myelin regeneration (p value=0.0189) while graphene oxide failed to further increase this effect. Fr did not prove effective in promoting nerve regeneration and was detrimental to myelin synthesis