Abstract
Peripheral nerve injuries affect a great amount of trauma patients annually. Development of nerve conduits will likely allow scientific and medical communities to improve functional recovery after nerve injuries. However, the efficacy of nerve conduits is often compromised by the lack of cells within the conduit, molecular factors enriched microenvironment and the extracellular matrix (ECM) mimetic spatial arrangement for nerve regeneration. In this study, a multi-channeled scaffold combined with aligned nanofibers and neurotrophic gradient (MC/AN/NG) was developed to attract axon outgrowth and mimic the fascicular architecture of ECM. In mechanical test, the result confirmed that a multi-channeled (MC) scaffold crosslinked with microbial transglutaminase (mTG) was stronger as demonstrated by the higher ultimate tensile strength and Young's modulus compared to untreated one. Nerve growth factor (NGF) release profile exhibited a discontinuous concentration gradient from 6.6 ng/mL to 107.2 ng/mL. In in vitro study, differentiated neural stem cells (dNSCs) could extend their neurites along the aligned nanofibrous structure. The cell density increased in higher NGF concentration region of gradient membrane. BDNF promoted myelination more significantly than the non-treated and NGF-treated groups, evidenced by the immunostaining. In in vivo study, the MC/AN/NG scaffold was used for bridging a 15 mm gap in a rabbit sciatic nerve transection model. The MC/AN/NG scaffold achieved functional recovery comparable to autograft as evidenced by significantly improved nerve function and fascicular morphology. From the above result findings, we suggests that the MC/AN/NG scaffold could be a promising nerve guidance conduit for peripheral nerve regeneration.