Functional Outcomes of Nerve Allografts Seeded with Undifferentiated and Differentiated Mesenchymal Stem Cells in a Rat Sciatic Nerve Defect Model.

Background: Mesenchymal stem cells have the potential to produce neurotrophic growth factors and establish a supportive microenvironment for neural regeneration. The purpose of this study was to determine the effect of undifferentiated and differentiated mesenchymal stem cells dynamically seeded onto decellularized nerve allografts on functional outcomes when used in peripheral nerve repair.

Methods: In 80 Lewis rats, a 10-mm sciatic nerve defect was reconstructed with (1) autograft, (2) decellularized allograft, (3) decellularized allograft seeded with undifferentiated mesenchymal stem cells, or (4) decellularized allograft seeded with mesenchymal stem cells differentiated into Schwann cell-like cells.

Gene expression profiles of human adipose-derived mesenchymal stem cells dynamically seeded on clinically available processed nerve allografts and collagen nerve guides.

It was hypothesized that mesenchymal stem cells (MSCs) could provide necessary trophic factors when seeded onto the surfaces of commonly used nerve graft substitutes. We aimed to determine the gene expression of MSCs when influenced by Avance® Nerve Grafts or NeuraGen® Nerve Guides. Human adipose-derived MSCs were cultured and dynamically seeded onto 30 Avance® Nerve Grafts and 30 NeuraGen® Nerve Guides for 12 hours.

Introducing human adipose-derived mesenchymal stem cells to Avance nerve grafts and NeuraGen nerve guides.

Background: When direct nerve coaptation is impossible after peripheral nerve injury, autografts, processed allografts, or conduits are used to bridge the nerve gap. The purpose of this study was to examine if human adipose-derived Mesenchymal Stromal/Stem Cells (MSCs) could be introduced to commercially available nerve graft substitutes and to determine cell distribution and the seeding efficiency of a dynamic seeding strategy.

Methods: MTS assays examined the viability of human MSCs after introduction to the Avance Nerve Graft and the NeuraGen Nerve Guide.

Adipose derived mesenchymal stem cells seeded onto a decellularized nerve allograft enhances angiogenesis in a rat sciatic nerve defect model.

Purpose: Adipose derived mesenchymal stem cells (MSCs) are hypothesized to supplement tissues with growth factors essential for regeneration and neovascularization. The purpose of this study was to determine the effect of MSCs with respect to neoangiogenesis when seeded onto a decellularized nerve allograft in a rat sciatic nerve defect model.

Methods: Allograft nerves were harvested from Sprague-Dawley rats and decellularized.

Gene expression and growth factor analysis in early nerve regeneration following segmental nerve defect reconstruction with a mesenchymal stromal cell-enhanced decellularized nerve allograft.

Unlabelled: The purpose of this study was to evaluate the molecular mechanisms underlying nerve repair by a decellularized nerve allograft seeded with adipose-derived mesenchymal stromal cells (MSCs) and compare it to the unseeded allograft and autograft nerve.

Methods: Undifferentiated MSCs were seeded onto decellularized nerve allografts and used to reconstruct a 10 mm gap in a rat sciatic nerve model. Gene expression profiles of genes essential for nerve regeneration and immunohistochemical staining (IHC) for PGP9.

Gene expression profiles of differentiated and undifferentiated adipose derived mesenchymal stem cells dynamically seeded onto a processed nerve allograft.

Background: Differentiation of mesenchymal stem cells (MSCs) into Schwann-like cells onto processed nerve allografts may support peripheral nerve repair. The purpose of this study was to understand the biological characteristics of undifferentiated and differentiated MSCs before and after seeding onto a processed nerve allograft by comparing gene expression profiles.

Methods: MSCs from Lewis rats were cultured in maintenance media or differentiated into Schwann-like cells.

Adhesion, distribution, and migration of differentiated and undifferentiated mesenchymal stem cells (MSCs) seeded on nerve allografts.

Background: Although undifferentiated MSCs and MSCs differentiated into Schwann-like cells have been extensively compared in vitro and in vivo, studies on the ability and efficiency of differentiated MSCs for delivery into nerve allografts are lacking. As this is essential for their clinical potential, the purpose of this study was to determine the ability of MSCs differentiated into Schwann-like cells to be dynamically seeded on decellularized nerve allografts and to compare their seeding potential to that of undifferentiated MSCs.

Methods: Fifty-six sciatic nerve segments from Sprague Dawley rats were decellularized, and MSCs were harvested from Lewis rat adipose tissue.

Seeding decellularized nerve allografts with adipose-derived mesenchymal stromal cells: An in vitro analysis of the gene expression and growth factors produced.

Mesenchymal stromal cells (MSCs) secrete many soluble growth factors and have previously been shown to stimulate nerve regeneration. MSC-seeded processed nerve allografts could potentially be a promising method for large segmental motor nerve injuries. Further progress in our understanding of how the functions of MSCs can be leveraged for peripheral nerve repair is required before making clinical translation.

Collagen Nerve Conduits and Processed Nerve Allografts for the Reconstruction of Digital Nerve Gaps: A Single-Institution Case Series and Review of the Literature.

Objective: A single-institution case series is reported and a review of the literature on the outcomes of digital nerve gap reconstruction with the NeuraGen type 1 collagen nerve conduit (Integra Life Sciences, Plainsboro New Jersey, USA) and the Avance Nerve Graft (Axogen Inc., Alachua, Florida, USA) is presented.

Methods: Thirty-seven patients were included with a minimal follow-up of 12 months.

In Vivo Survival of Mesenchymal Stromal Cell-Enhanced Decellularized Nerve Grafts for Segmental Peripheral Nerve Reconstruction.

Purpose: Adipose-derived mesenchymal stromal cells (MSCs) have emerged as promising tools for peripheral nerve reconstruction. There is a paucity of information regarding the ultimate survivorship of implanted MSCs or whether these cells remain where they are placed. The aim of the present study was to track the in vivo distribution and survival of MSCs seeded on a decellularized nerve allograft reconstruction of a peripheral nerve defect using luciferase-based bioluminescence imaging (BLI).

A Simple Dynamic Strategy to Deliver Stem Cells to Decellularized Nerve Allografts.

Background: The addition of adipose-derived mesenchymal stromal cells to decellularized nerve allografts may improve outcomes of nerve reconstruction. Prior techniques used for cell seeding are traumatic to both the mesenchymal stromal cells and nerve graft. An adequate, reliable, and validated cell seeding technique is an essential step for evaluating the translational utility of mesenchymal stromal cell-enhanced decellularized nerve grafts.

Spinal accessory nerve to triceps muscle transfer using long autologous nerve grafts for recovery of elbow extension in traumatic brachial plexus injuries.

Despite continuous improvement and expansion of reconstructive options for traumatic brachial plexus injury, options to reinnervate the triceps muscle remain somewhat sparse. This study describes a novel option, using a spinal accessory nerve transfer to the long head of the triceps muscle with an intervening autologous nerve graft. The resulting quality of elbow extension and factors that influence outcome are discussed.

Ultrasound assessment of the sural nerve in patients with neuropathic pain after ankle surgery.

Introduction: The sural nerve may be damaged after ankle injury. The aim of our study was to determine the diagnostic utility of high-resolution sonography in patients with ankle fractures treated by open reduction and internal fixation in whom there was a clinical suspicion of sural neuropathy.

Methods: We examined the ultrasound (US) characteristics of patients with and without postsurgical sural neuropathic pain and healthy volunteers.

High Prevalence of Chronic Pain With Neuropathic Characteristics After Open Reduction and Internal Fixation of Ankle Fractures.

Background: Unstable ankle fractures require treatment with open reduction and internal fixation (ORIF). Long-term functional outcome is satisfying in most patients; however, a number of patients have persistent complaints. Superficial nerve complications following ankle surgery may be the cause of chronic pain and disability.

The Role of Nerve Graft Substitutes in Motor and Mixed Motor/Sensory Peripheral Nerve Injuries.

Alternatives to nerve autograft have been invented and approved for clinical use. The reported outcomes of these alternatives in mixed motor nerve repair in humans are scarce and marked by wide variabilities. The purpose of our Current Concepts review is to provide an evidence-based overview of the effectiveness of nerve conduits and allografts in motor and mixed sensory/motor nerve reconstruction.

Noninvasive Ultrasound of the Tibial Muscle for Longitudinal Analysis of Nerve Regeneration in Rats.

Background: Today's criterion standards for measuring functional recovery after nerve trauma in experimental studies are the muscle mass ratio and the isometric tetanic force; both tests are invasive and require a sacrificial procedure. The authors propose ultrasound as a noninvasive method to determine muscle atrophy, and evaluate its validity and reliability by comparing it to muscle mass ratio, isometric tetanic force, and histology.

Methods: Fifty rats sustained a 10-mm autograft sciatic nerve reconstruction.