Regeneration of the dog's axotomized sciatic nerve with pregnenolone-saturated chitosan prosthesis implanted through the tubulization technique

Abstract

PERIPHERAL NERVES CAN BE INJURED BY TRAUMATISMS OR MECHANICAL CAUSES, AND THERMAL, ISCHEMIC OR TUMORAL DAMAGE, THIS COULD PRESENT INCONVENIENCES OF THE MOBILITY, SENSIBILITY AND LOSS OF MOTOR FUNCTION AT THE DENERVATED AREA. THE SURGICAL TECHNIQUES APPLIED TO REPAIR NERVES HAVE GONE THROUGH SEVERAL PHASES OF EVOLUTION SUCH AS THE TUBULIZATION TECHNIQUE WHICH CONSISTS OF A PROSTHESIS WITH A PIPE SHAPE AT THE SEGMENT INJURED. IN THIS WORK THE BIOMATERIAL UTILIZED TO MANUFACTURE THE PROSTHESIS WAS CHITOSAN, SINCE THIS COMPOUND ALLOWS TO INCORPORATE TO ITS MATRIX PROMOTING NERVOUS GROWING SUBSTANCES THAT ARE RELEASED IN SITU FOR A LONG TIME WHILE BEING DEGRADED BY TITULAR LYSOSOMES OF ORGANIC ORIGIN. IT IS KNOWN, BY DIVERSE STUDIES, THAT SEVERAL NEUROSTEROIDS ARE INVOLVED DURING THE REGENERATION PROCESS OF PERIPHERAL NERVES, WHICH FUNCTIONS ARE ALREADY DESCRIBED, AS PREGNENOLONE. IN ORDER TO DETERMINE IF THERE WAS OR NOT REGENERATION AND THE DEGREE OF MATURITY OF THIS ,12 YOUNG FRENCH POODLE FEMALE DOGS OF 1 TO 1.5 YEARS OLD WERE USED (FOUR WERE USED AS INTACT CONTROL GROUP, FOUR WERE SUBJECTED TO TUBULIZATION TECHNIQUE WITH CHITOSAN, AND FOUR WENT INTO TUBULIZATION TECHNIQUE WITH CHITOSAN AND PREGNENOLONE NEUROSTEROID, WHICH IS A STEM HORMONE), IN ORDER TO CORRECT 15 MM OF AXOTOMIZED SEGMENT. THE REGENERATED NERVES WERE EVALUATED BY MEANS OF ELECTRONIC MICROSCOPY OF TRANSMISSION AND LIGHT, PERFORMING CROSS CUTS OF 60-70 NM AND 1 ?M IN THICKNESS FOR THEIR HISTOLOGICAL ANALYSIS. THE MORPHOLOGICAL FINDINGS SHOWED A SIMILAR STRUCTURE TO THAT OF AN INTACT NERVE, SINCE THE NUMBER OF MYELINATED AXONS, NOT MYELINATED AND THE PROPORTION "G" (WHICH INDICATES THE RIPENING DEGREE OF THE AXON), WERE SIMILAR, INDICATING THAT THE REGENERATION OF THE AXOTOMIZED NERVES AND TUBULIZATION WAS ACHIEVED, INDEPENDENTLY OF THE ADMINISTERED TREATMENT.