Human Hair Derived Keratins Mediate Schwann Cell Behavior in vitro and Facilitate Rapid Peripheral Nerve Regeneration in vivo

Nerve defects are a common result of peripheral nerve injury and present a significant challenge clinically. Keratins extracted from human hair fiber are a novel group of biomaterials with superior biocompatibility to many synthetic and naturally derived scaffolds. The specific aims of this study were to investigate the ability of human hair keratins to mediate Schwann cell behavior in vitro and to determine whether keratin scaffolds are capable of accelerating functional nerve regeneration in vivo. Using a variety of in vitro assays we have found that keratins increase Schwann cell proliferation, migration and attachment. In addition, keratins have the ability to self‐assemble into fibrous and highly porous scaffolds suitable for cell infiltration and axonal growth. To determine whether a keratin hydrogel scaffold could facilitate functional nerve regeneration in vivo, a tibial nerve axotomy mouse model was employed. After 6 weeks, the extent of regeneration was evaluated using electrophysiology and muscle force testing. Functional testing showed that keratin filled conduits significantly enhanced the nerve regeneration process in comparison to empty conduit controls, and were comparable to autograft. This data demonstrates that keratin hydrogels serve as effective scaffolds for neural tissue engineering and may facilitate functional nerve regeneration by acting on Schwann cells.