(Chitosan-g-glycidyl methacrylate)-xanthan hydrogel implant in Wistar rats for spinal cord regeneration

This work reports the results of in vivo assays of an implant composed of the hydrogel Chitosan-g-Glycidyl Methacrylate-Xanthan [(CTS-g-GMA)-X] in Wistar rats. Degradation kinetics of hydrogels was assessed by lysozyme assays. Wistar rats were subjected to laminectomy by cutting the spinal cord with a scalpel. After the surgical procedure, hydrogels were implanted in the injured zone (level T8). Somatosensory evoked potentials (SEPs) obtained by electric stimulation onto periphery nerves were registered in the corresponding central nervous system (CNS) areas. Rats implanted with the biomaterials showed a successful recovery compared with the non-implanted rats after 30days. Lysozyme, derived from egg whites, was used for in vitro assays. This study serves as the basis for testing the biodegradability of the hydrogels (CTS-g-GMA)-X that is promoted by enzymatic hydrolysis. Hydrogels' hydrolysis was studied via lysozyme kinetics at two pH values, 5 and 7, under mechanical agitation at 37°C. Results show that our materials' hydrolysis is slower than pure CTS possibly due to the steric hindrance imposed by the GMA grafting of functionalization. This hydrolysis helps degrade the biomaterial and at the same time it provides support for spinal cord recovery. Combination of these results may prove useful in the use of these hydrogels as scaffolds for cells proliferation and their application as implants in living organisms.