Acellular Cauda Equina Allograft as Main Material Combined with Biodegradable Chitin Conduit for Regeneration of Long‐Distance Sciatic Nerve Defect in Rats

Abstract

Autologous nerve grafting (ANG), the gold standard treatment for peripheral nerve defects, still has many restrictions. In this study, the acellular cauda equina allograft (ACEA), which consists of biodegradable chitin conduit and acellular cauda equina, is developed. The cauda equina is able to complete decellularization more quickly and efficiently than sciatic nerves under the same conditions, and it is able to reserve more basal lamina tube. In vitro, ACEA shows superior guidance capacity for the regeneration of axons and migration of Schwann cells compared to acellular sciatic nerve allograft (ASNA) in dorsal root ganglion culture. In vivo, ACEA is used to bridge 15 mm long-distance defects in rat sciatic nerves. On day 21 after transplantation, the regenerative distance of neurofilaments in the grafting segment is not significantly different between the ACEA and ANG groups. At week 12, ACEA group shows better sciatic nerve repair than chitin conduit only and ASNA groups, and the effect is similar to that in the ANG group as determined by gait analysis, neural electrophysiological, and histological analyses. The above results suggest that the ACEA has the potential to become a new biological material as a replacement for autografting in the treatment of long-distance nerve defects.

A nerve conduit filled with Wnt5a‐loaded fibrin hydrogels promotes peripheral nerve regeneration

“…However, the autograft group was superior in terms of SFI, wet weight ratio of the gastrocnemius muscle, and CMAP amplitude compared with the Wnt5a/Fn group, which was similar to previous studies. 44,45 The SFI and wet weight ratio of the gastrocnemius muscle are crucial indicators for motor function recovery, 21,25 and the CMAP amplitude is associated with the number of reinnervated muscle fibers. 46 Thus, we speculate that the repair effect of the Wnt5a/Fn group remains inferior to that of the autograft group, which mainly for the following reasons.…”

“…The loading capacity (w/w%) was calculated based on the absorbance. 19 At specific time points (1,3,7,12,14,21,28, and 35 days), we tested the upper layer solution and subsequently added an equal amount of phosphate buffer saline solution (2 µL). The amount of Wnt5a in the samples was detected via UV-via-NIR spectroscopy.…”

“…20,24 Before the experiment, the SD rats were placed on the CatWalk XT machine (Noldus) for training to have consecutive uninterrupted runs. 21 Twelve weeks after the operation, the motor function of the SD rats was evaluated using the CatWalk XT 10.6 gait analysis system (Noldus). The walking tracks and footprints were recorded for the gait analysis.…”

Functional tissue-engineered microtissue formed by self-aggregation of cells for peripheral nerve regeneration

“…When there is a long segmental nerve defect, the effect of direct end-to-end anastomosis is poor due to high tension [ 4 ]. At present, autologous nerve transplantation is still the standard gold method for treating long segmental nerve defects, but it has some limitations, such as limited donor sources, complications from second operations, and permanent denervation dysfunction of donor site [ 5 ]. Therefore, effective autologous nerve replacement is critical in the field of peripheral nerve regeneration.…”

Nanochannel‐Based Poration Drives Benign and Effective Nonviral Gene Delivery to Peripheral Nerve Tissue

“…[6] Additional concerns include donor site morbidity and donor tissue scarcity. [14] While acellular nerve allografts (ANAs) could potentially circumvent these issues, ANAs lack important cues for nerve tissue repair (e.g., Schwann and endothelial cells) and as such have poorer outcomes. [15][16][17] Alternative strategies focused on the use of scaffolds or other means typically fail to address distal effects from Wallerian degeneration, and/or fall short in being able to sustain growth over large defects.…”