UV-Casting on Methacrylated PCL for the Production of a Peripheral Nerve Implant Containing an Array of Porous Aligned Microchannels

Abstract

Peripheral nerves are basic communication structures guiding motor and sensory information from the central nervous system to receptor units. Severed peripheral nerve injuries represent a large clinical problem with relevant challenges to successful synthetic nerve repair scaffolds as substitutes to autologous nerve grafting. Numerous studies reported the use of hollow tubes made of synthetic polymers sutured between severed nerve stumps to promote nerve regeneration while providing protection for external factors, such as scar tissue formation and inflammation. Few approaches have described the potential use of a lumen structure comprised of microchannels or microfibers to provide axon growth avoiding misdirection and fostering proper healing. Here, we report the use of a 3D porous microchannel-based structure made of a photocurable methacrylated polycaprolactone, whose mechanical properties are comparable to native nerves. The neuro-regenerative properties of the polymer were assessed in vitro, prior to the implantation of the 3D porous structure, in a 6-mm rat sciatic nerve gap injury. The manufactured implants were biocompatible and able to be resorbed by the host’s body at a suitable rate, allowing the complete healing of the nerve. The innovative design of the highly porous structure with the axon guiding microchannels, along with the observation of myelinated axons and Schwann cells in the in vivo tests, led to a significant progress towards the standardized use of synthetic 3D multichannel-based structures in peripheral nerve surgery.

Graphene oxide and electroactive reduced graphene oxide-based composite fibrous scaffolds for engineering excitable nerve tissue

“…The average number of neurites expressed per NG108-15 neuronal cell body was estimated at ~1.4 (Fig. 6C), in line with what has been previously reported using the same NG108-15 cell line on other scaffolds [94,95]. The average number of neurites per neuronal cell body decreased at increased GO content, while no differences were observed among the rGO/silk composites.…”

A Tuneable, Photocurable, Poly(Caprolactone)-Based Resin for Tissue Engineering—Synthesis, Characterisation and Use in Stereolithography

“…A previous study from our group also highlighted the cytocompatibility of similar PCLMA material to that reported in this study. Neuronal and Schwann cells were cultured on PCLMA and shown to exhibit comparable viability compared to TCP controls as assessed via a live/dead assay [ 84 ]. In the same study, porous PCLMA nerve guidance conduits were used to repair rat sciatic nerve injuries and resulted in good tissue integration.…”

Basic Principles of Emulsion Templating and Its Use as an Emerging Manufacturing Method of Tissue Engineering Scaffolds

“…Casting enables the manufacturing of scaffolds in a wide range of shapes and sizes, depending on the mould design ( Paljevac et al, 2018 ; Diez-Ahedo et al, 2020 ; Dikici et al, 2020a ; Owen et al, 2020 ). Recently, Dikici et al (2020a) reported the fabrication of the PolyHIPEs in tubular form by designing a re-usable tubular silicone mould system that, HIPE can be injected into, polymerised, and recovered easily ( Figure 10Ab ).…”