Neuroregeneration and immune response after neurorrhaphy are improved with the use of heterologous fibrin biopolymer in addition to suture repair alone

Abstract

Introduction/Aims: Peripheral nerve injuries result in impaired neuromuscular interactions, leading to morphological and functional alterations. Adjuvant suture repair methods have been used to improve nerve regeneration and modulate the immune response. Heterologous fibrin biopolymer (HFB), a scaffold with adhesive properties, plays a critical role in tissue repair. The aim of this study is to evaluate neuroregeneration and immune response focusing on neuromuscular recovery, using sutureassociated HFB for sciatic nerve repair.Methods: Forty adult male Wistar rats were distributed into four groups (n = 10): C (control), only sciatic nerve location; D (denervated), neurotmesis and 6-mm gap removal and fixation stumps in subcutaneous tissue; S (suture), neurotmesis followed by suture; and SB (suture + HFB), neurotmesis followed by suture and HFB. Analysis of M2 macrophages (CD206 + ), as well as the morphology and morphometry of nerves, soleus muscle, and neuromuscular junctions (NMJs), were performed at 7 and 30 days after surgery. Results:The SB group had the highest M2 macrophage area in both periods. After 7 days, SB was the only group similar to the C group regarding the number of axons; furthermore, after 30 days, the SB group was closer to the C group concerning blood vessel and central myonuclear numbers, NMJ angle, and connective tissue volume.After 7 days, increases in nerve area, as well as the number and area of blood vessels, were also observed in SB.Discussion: HFB potentiates the immune response, increases axonal regeneration, induces angiogenesis, prevents severe muscle degeneration, and assists in NMJ recovery. In conclusion, suture-associated HFB has major implications for improved peripheral nerve repair.

Statin exposure during pregnancy promotes neuromuscular junction alterations in postpartum Wistar rats

“…1,30 In experimental models, intramuscular connective tissue infiltration and decreased muscle weight and area may act as possible indicators of muscle degeneration. [31][32][33] In our muscle tissue analysis, the numbers of muscle fibers with central nuclei were higher in the S and R groups when compared with C. Usually, myonuclei occupy the periphery of the myofibrils, whereas in pathological conditions the presence of central nuclei is higher. 34 Central nuclei usually appear after damage induced by a variety of injuries, including exposure to myotoxic drugs.…”

“…Magnetic resonance imaging studies in the lower limbs of patients affected by myopathy, including of anti–HMG‐CoA antibodies, the presence of which suggests SAMS, revealed generalized muscle edema of the affected musculature, fat infiltration due to inflammation, and fiber necrosis 1,30 . In experimental models, intramuscular connective tissue infiltration and decreased muscle weight and area may act as possible indicators of muscle degeneration 31–33 …”

Morphofunctional Improvement of the Facial Nerve and Muscles with Repair Using Heterologous Fibrin Biopolymer and Photobiomodulation

“…The methodology used in this experimental protocol was based on previous studies by our group on peripheral nerve regeneration, causing an injury to the buccal branch of the facial nerve in rats [ 37 , 38 , 83 ]. In these studies, it was proven that HFB has the capacity to allow the repair of the lesion with results similar to the gold standard of end-to-end neurorrhaphy, which uses suture thread [ 84 , 85 ]. In an unprecedented way, in the present study, we evaluated a protocol with a smaller number of PBM sessions and also the effects on facial muscles, through morphofunctional analysis.…”

Heterologous fibrin biopolymer as an emerging approach to peripheral nerve repair: a scoping review

“…In a recent study, we demonstrated the early beneficial effects of the use of HFB in conjunction with two sutures for the repair of transected sciatic nerves in rats [ 13 ]. HFB application in comparison to suture alone improved overall nerve regeneration, with increased axonal growth and tissue vascularization (angiogenesis), proper restoration of neuromuscular junctions, reduced severe muscle degeneration (collagen infiltration), and enhanced relative area of M2 markers, 7 and 30 days after reconstruction.…”

“…The use of HFB as an adjunct in peripheral and central nerve reconstruction has been showing promising results through the development of an immunomodulatory and neuroprotective environment at the injury site [ 10 - 13 ] and has also been applied in various other experimental models of reconstructive surgery [ 7 , 14 ]. The use of HFB has already been experimentally shown to provide a microenvironment of stability and protection at the reconstruction site, leading to positive scenarios of nerve regeneration.…”