A 3D-engineered porous conduit for peripheral nerve repair

Abstract

End-to-end neurorrhaphy is the most commonly used method for treating peripheral nerve injury. However, only 50% of patients can regain useful function after treating with neurorrhaphy. Here, we constructed a 3D-engineered porous conduit to promote the function recovery of the transected peripheral nerve after neurorrhaphy. The conduit that consisted of a gelatin cryogel was prepared by molding with 3D-printed moulds. Due to its porous structure and excellent mechanical properties, this conduit could be collapsed by the mechanical force and resumed its original shape after absorption of normal saline. This shape-memory property allowed a simply surgery process for installing the conduits. Moreover, the biodegradable conduit could prevent the infiltration of fibroblasts and reduce the risk of scar tissue, which could provide an advantageous environment for nerve regeneration. The efficiency of the conduits in assisting peripheral nerve regeneration after neurorrhaphy was evaluated in a rat sciatic nerve transected model. Results indicated that conduits significantly benefitted the recovery of the transected peripheral nerve after end-to-end neurorrhaphy on the static sciatic index (SSI), electrophysiological results and the re-innervation of the gastrocnemius muscle. This work demonstrates a biodegradable nerve conduit that has potentially clinical application in promoting the neurorrhaphy.

The advances in nerve tissue engineering: From fabrication of nerve conduit toin vivonerve regeneration assays

“…As a natural protein biopolymer, gelatin possesses some beneficial properties such as availability, cost‐effectiveness, biocompatibility, biodegradability, having no toxic by‐products after enzymatic degradation, stimulation of cellular adhesion, and suitability for drug delivery (Elzoghby, ) and releasing growth factors (Chang et al, ). Previous studies have also shown that the use of gelatin conduits produced by various methods stimulates damaged nerve growth in a rat model (Ko et al, ; Tao et al, ). Moreover, it has been exhibited that NGF immobilized on SC‐loaded gelatin conduits can improve nerve regeneration in a 10‐mm rat sciatic nerve gap model (Chen et al, ).…”

“…The axonal growth is a critical factor during peripheral nerve regeneration. Some of the markers associated with nerve growth are growth‐associated protein 43 (Tao et al, ), neurofilament 200 (Stenberg et al, ), β‐III tubulin (Carriel, Garzón, Campos, Cornelissen, & Alaminos, ), and protein gene product 9.5 (Mobasseri et al, ). In some studies focusing on peripheral nerve regeneration, the expression level of neuronal markers has been determined by quantitative reverse‐transcription polymerase chain reaction and western blot (Hu, Chen, & Wang, ).…”

“…In most studies, on the basis of their frequency of usage (high vs. low), animals such as rats (Labroo et al, ; Tao et al, ), mice (Lin, Shea, et al, ; Yokoi et al, ), rabbits (Chang et al, ; Hsu, Chan, Chiang, Chen, & Jiang, ), dogs (Cui et al, ; Yao et al, ), cats (Kitahara et al, ), sheep (Siemionow et al, ), and monkeys (Zhang et al, ) are used (Angius et al, ).…”

“…The conduit implantation investigations on the rat sciatic nerve use most often male rats weighing 200−250 g (Tao et al, ). Sprague Dawley (Hu et al, ; Zhuang et al, ) and Wistar rats (Abbasipour‐Dalivand, Mohammadi, & Mohammadi, ; Foroutan et al, ) are the most commonly used species, because articles analysis revealed that these strains are most commonly used in regeneration studies.…”

Biomimetic neural scaffolds: a crucial step towards optimal peripheral nerve regeneration

“…33 There are many factors that impact the efficacy of nerve conduits, including thickness, porosity, and flexibility. Studies have shown that the conduit thickness is closely related to neuroma formation, 34 and that thicknesses greater than 0.81 mm attenuate axonal outgrowth.…”