Relevance and Recent Developments of Chitosan in Peripheral Nerve Surgery.

A Boecker,S C Daeschler,U Kneser,L Harhaus

doi:10.3389/fncel.2019.00104

Abstract

Developments in tissue engineering yield biomaterials with different supporting strategies to promote nerve regeneration. One promising material is the naturally occurring chitin derivate chitosan. Chitosan has become increasingly important in various tissue engineering approaches for peripheral nerve reconstruction, as it has demonstrated its potential to interact with regeneration associated cells and the neural microenvironment, leading to improved axonal regeneration and less neuroma formation. Moreover, the physiological properties of its polysaccharide structure provide safe biodegradation behavior in the absence of negative side effects or toxic metabolites. Beneficial interactions with Schwann cells (SC), inducing differentiation of mesenchymal stromal cells to SC-like cells or creating supportive conditions during axonal recovery are only a small part of the effects of chitosan. As a result, an extensive body of literature addresses a variety of experimental strategies for the different types of nerve lesions. The different concepts include chitosan nanofibers, hydrogels, hollow nerve tubes, nerve conduits with an inner chitosan layer as well as hybrid architectures containing collagen or polyglycolic acid nerve conduits. Furthermore, various cell seeding concepts have been introduced in the preclinical setting. First translational concepts with hollow tubes following nerve surgery already transferred the promising experimental approach into clinical practice. However, conclusive analyses of the available data and the proposed impact on the recovery process following nerve surgery are currently lacking. This review aims to give an overview on the physiologic properties of chitosan, to evaluate its effect on peripheral nerve regeneration and discuss the future translation into clinical practice.

Highlights

2.8% of all hospitalized trauma patients suffer from traumatic peripheral nerve injury (Noble et al, 1998)
Various materials have been tested for bridging peripheral nerve defects reaching from non-resorbable materials like silicon (Lundborg, 2004) to fully biodegradable materials such as Collagen or polyglycolic acid (PGA) (Inada et al, 2007; Bozkurt et al, 2012; Boecker et al, 2015)
Despite substantial developments in tissue engineering, there is still no material or bio-mimicking concept, which revealed superior results in peripheral nerve regeneration compared to the autologous nerve transplantation (ANT) as the current gold standard for bridging peripheral nerve defects (Deumens et al, 2010)

Summary

Introduction

2.8% of all hospitalized trauma patients suffer from traumatic peripheral nerve injury (Noble et al, 1998). If tension free coaptation is not achievable, the autologous nerve transplantation (ANT) is the current gold standard (Deumens et al, 2010). Various materials have been tested for bridging peripheral nerve defects reaching from non-resorbable materials like silicon (Lundborg, 2004) to fully biodegradable materials such as Collagen or PGA (Inada et al, 2007; Bozkurt et al, 2012; Boecker et al, 2015). It is a common consent that the material used to support the peripheral nerve regeneration should ideally base on a fully degradable matrix without negatively influencing the regeneration during biodegradation process (Schmidt and Leach, 2003). Despite substantial developments in tissue engineering, there is still no material or bio-mimicking concept, which revealed superior results in peripheral nerve regeneration compared to the ANT as the current gold standard for bridging peripheral nerve defects (Deumens et al, 2010)

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