In vitro models for peripheral nerve regeneration

Abstract

The study of peripheral nerve repair and regeneration is particularly relevant in the light of the high clinical incidence of nerve lesions. However, the clinical outcome after nerve lesions is often far from satisfactory and the functional recovery is almost never complete. Therefore, a number of therapeutic approaches are being investigated, ranging from local delivery of trophic factors and other molecules to bioactive biomaterials and complex nerve prostheses. Translation of the new therapeutic approaches to the patient always requires a final pre-clinical step using in vivo animal models. The need to limit as much as possible animal use in biomedical research, however, makes the preliminary use of in vitro models mandatory from an ethical point of view. In this article, the different types of in vitro models available today for the study of peripheral nerve regeneration have been ranked by adopting a three-step stair model based on their increasing ethical impact: (i) cell line-based models, which raise no ethical concern; (ii) primary cell-based models, which have low ethical impact as animal use, although necessary, is limited; and (iii) organotypic ex vivo-based models, which raise moderate ethical concerns as the use of laboratory animals is required although with much lower impact on animal wellbeing in comparison to in vivo models of peripheral nerve regeneration. This article aims to help researchers in selecting the best experimental approach for their scientific goals driven by the 'Three Rs' (3Rs) rules (Replacement, Reduction or Refinement of animal use in research) for scientific research.

Schwannoma of the hypoglossal nerve: Review of the literature based on an illustrative case

“…In these cases, in order to limit morbidity, reconstruction by direct nerve repair with epineurial microsutures or nervous grafts may be performed. In addition to these procedures, there are novel and upcoming techniques using biocompatible scaffolds that may help in the reconstruction of the transected nerve (32)(33)(34)(35)(36).…”

The role of growth factors in nerve regeneration

“…The explanation about the neurotrophic factors especially functions and roles of them in the nervous system has still been increasing including embryonic and postnatal development after injury. There are many studies mention main aims of neurotrophic factor researches involved in developmental roles, plasticity in the central nervous system, and mechanisms of injury and signal transduction (1)(2)(3)(4)(5)(6)(7)(8). The objective of this review is to give an overview of neurotrophic factors and emphasize importance of what we know about the functional mechanisms by which neurotrophic factors reveal their effects from an injury response window, including axonal growth and regeneration.…”

Polymeric scaffolds for three-dimensional culture of nerve cells: a model of peripheral nerve regeneration

“…[36] The appropriate selection of cells for the in vitro cellular models will support projections and expectations for potential in vivo models. Moreover, in vitro cellular models are not necessarily subjected to regulations as with animal or human models.…”

“…Their outgrowth have been demonstrated both alone or when co-cultured with SCs. [36]–[38] DRGs are a pivotal test subject for experiments using growth and/or regulatory factors. [39] …”