Hide/Show Apps

Design and in vitro testing of a peripheral nerve guide

Tamay, Dilara Göksu
Regeneration after peripheral nerve injury (PNI) is limited as chondroitin sulfate proteoglycans (CSPGs) within the scar tissue inhibit axon outgrowth. Nerve guides (NGs) are alternatives to the “gold standard” autografting, which has limitations including donor site morbidity and limited tissue availability. NGs are tubular constructs designed to form a bridge between the transected nerve ends, provide physical support, and achieve axon guidance via topographical and/or chemical cues. This study aims to design and test the in vitro performance of a NG with topographical cues, capable of removing CSPGs via release of enzyme chondroitinase ABC (ChABC). A bisphenol A methacrylate (Dental SG)-based NG filled with crosslinked gelatin methacrylate (GelMA) hydrogel containing microchannels was constructed. For practical observation, a halved tube was used for in vitro testing. Cell adhesion and viability analyses were conducted in vitro using neuron-like PC12 cell line. Optimum GelMA concentration was determined as 15% (w/v). In vitro studies showed hydrogel provides cells with the optimal conditions for attachment and growth. Enzyme release from alginate (using BSA as a model) was in accordance to Korsmeyer-Peppas model with a 100% release achieved in ~3 days. 3D printed Dental SG exterior was shown to significantly degrade in the presence of cells. The effectiveness of NG in supporting cell viability and growth was tested in vitro. Cells showed good attachment and were viable along the microchannels with visible alignment during 3 days of incubation. However, due to possible toxic effect of Dental SG degradation products, cells did not survive until Day 7.