[Regeneration of the axotomised sciatic nerve in dogs using the tubulisation technique with Chitosan biomaterial preloaded with progesterone]

Abstract

Introduction: Injuries to peripheral nerves can have different causes and may lead to disorders affecting mobility, sensitivity and loss of motor function as they progress. Weiss, in 1944, introduced tubulisation to promote the regeneration of a sectioned nerve. In this study the biomaterial Chitosan was used to induce and stimulate the regeneration of the sciatic nerve in dogs. At the same time, we took advantage of the characteristics offered by Chitosan to include the neurosteroid progesterone in its matrix, as a promoter of axonal growth. AIMS. The aim of our study was to determine the degree of regeneration of the sciatic nerve in dogs when axotomised tubulised with a Chitosan prosthesis steeped in the neurosteroid progesterone.

Materials and methods: Young adult female dogs were used to evaluate the regeneration of the sciatic nerve induced at a standard of 15 mm; regeneration was determined by means of an axonal growth chamber. Nerve growth was studied through histological analysis and by electron microscope.

Results: The statistical analysis showed that there were no significant differences in the number of myelinated fibres between the experimental groups. The electron microscope images of the transmission in the regenerated nerves in the groups that were tubulised with Chitosan, with and without neurosteroid preloading, revealed an advanced regenerative process. This was evidenced by the fact that collagen fibres, elastin, Schwann cells and both myelinated and non myelinated fibres were observed in all cases.

Conclusions: The regeneration of axotomised, tubulised nerves was achieved regardless of the treatment that was applied. The distal nerve segment that was analysed revealed a similar structure to that of a normal nerve.