Keratin Gel Filler for Peripheral Nerve Repair in a Rodent Sciatic Nerve Injury Model

BACKGROUND: Restoration with sufficient functional recovery after long-gap peripheral nerve damage remains a clinical challenge. In vitro, keratins, which are derived from human hair, enhance activity and gene expression of Schwann cells. The specific aim of the authors' study was to examine keratin gel as conduit filler for peripheral nerve regeneration in a rat sciatic nerve injury model. METHODS: Incorporation of glial cell line-derived, neurotrophic factor, double-walled microspheres into polycaprolactone nerve guides has demonstrated an off-the-shelf product alternative to promote nerve regeneration, and this conduit was filled with keratin gel and examined in a rat 15-mm sciatic nerve defect model. As an indicator of recovery, nerve sections were stained with S100 and protein gene product 9.5 antibody. RESULTS: The keratin-treated groups, compared with both saline and empty polycaprolactone (control) groups (p < 0.05), demonstrated a significantly increased density of Schwann cells and axons. Polycaprolactone-based nerve conduits possess optimal mechanical and degradative properties, rendering the biocompatible conduits potentially useful in peripheral nerve repair. CONCLUSION: From their studies, the authors conclude that polycaprolactone nerve guides with glial cell line-derived, neurotrophic factor-loaded, double-walled microspheres filled with keratin gel represent a potentially viable guiding material for Schwann cell and axon migration and proliferation in the treatment of peripheral nerve regeneration.