Evaluating the Effectiveness of the Experimental Use of the Collagen Conduit Filled With Dermal hydrogel to Repair a Peripheral Nerve Defect

Abstract

Background: Current studies show that hollow conduits in combination with various synthetic and biological fillers significantly accelerate functional recovery of peripheral nerves. One of such fillers can be a hydrogel based on the extracellular matrix of the dermis, which contains surface ligands capable of providing topographic and biological signals for nerve regeneration.Objective: To evaluate the effectiveness of rat sciatic nerve regeneration using a collagen conduit filled with dermal hydrogel in an in vivo experiment.Materials and methods: We evaluated the effectiveness of the NeuraGen® collagen conduit filled with dermal hydrogel and compared it with that of an autograft and the NeuraGen® hollow collagen conduit in experimental treatment of rat sciatic nerve defects larger than 1 cm. Male Wistar rats underwent sciatic nerve resection. We calculated the Sciatic Functional Index (SFI) and ratio of the calf circumference in an operated limb to that in an intact limb on days 30, 60, and 90 after implantation. We performed electrophysiological tests and explanted samples for hematoxylin-eosin staining on day 90 of the experiment.Results: When assessing the SFI and electrophysiological parameters, the group of animals with autografts and the group with the NeuraGen® collagen conduits filled with dermal hydrogel demonstrated similar results. We observed muscle atrophy, low SFI scores, and low velocity and short duration of the action potential in the group with the hollow NeuraGen® collagen conduits. Histological analysis of explanted samples of the collagen conduits filled with dermal hydrogel demonstrated areas of glial proliferation and the absence of pronounced degeneration of nerve fibers throughout the implant compared with autografts, indicating functional regeneration of nerve fibers.Conclusions: Evaluation of the effectiveness of rat sciatic nerve regeneration showed that the NeuraGen® collagen conduit filled with dermal hydrogel provides functional and morphological integration with the nerve compared with an autograft. Our findings can be used for further development and improvement of nerve conduits.