Study of neuromuscular interaction after neurorrhaphy associated with heterologous fibrin biopolymer: morphological and functional aspects

• Grant number: 23/16239-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2024
• End date: May 31, 2025
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Selma Maria Michelin Matheus
• Grantee: Manuela Almeida e Silva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Nerves are fragile structures prone to being damaged by trauma that causes interruption of nerve conduction. Peripheral nerve injuries (PNLs) affect, in addition to the nerve, the innervated muscle and associated neuromuscular junctions (NMJs), leading to several changes. Despite advances in surgical techniques, recovery after LNP is rarely complete. Adjuvant methods have been used to accelerate nerve regeneration and enhance neuromuscular recovery, including the heterologous fibrin biopolymer (BHF). The objective of this study will be to evaluate the effects of nerve reconstruction via neurorrhaphy associated with BHF, with an emphasis on nerve regeneration and the morphofunctional aspects of neuromuscular interaction. 40 adult male Wistar rats (CEUA-FMB: 1402/2021) will be used, divided into 4 groups: Control (C): dissection and location of the right sciatic nerve; Denervated (D): nerve transection (neurotmesis) and removal of a 6 mm fragment; Neurorrhaphy (N): neurotmesis followed by end-to-end neurorrhaphy; Neurorrhaphy + BHF (NB): neurotmesis followed by neurorrhaphy and the addition of 250µL of BHF. Before the surgeries and every two weeks afterwards, functional gait analysis (CatWalk XT) will be carried out on all animals according to the experimental groups. At 120 days after surgery, the animals will be euthanized and the sciatic nerves and right soleus muscles collected, fixed and processed for analysis: morphology and morphometry of the sciatic nerve and muscle fibers, quantification of intramuscular connective tissue, morphology of the NMJs by confocal microscopy