Treatment of a Spinal Cord Hemitransection Injury with Keratin Biomaterial Hydrogel Elicits Recovery and Tissue Repair

Abstract

Medical care costs can reach an estimated value of $4 billion for spinal cord injuries (SCI) each year in the USA alone. With no viable treatment options available, care remains palliative and aims to minimize lifelong disabilities and complications, such as immobility, bladder and bowel dysfunction, breathing problems, and blood clots. Human hair keratin biomaterials have demonstrated efficacy in peripheral nerve injury models and were shown to improve conduction delay and increase axon number and density. In this study, a keratin hydrogel was tested in a central nervous system (CNS) application of spinal cord hemisection injury. Keratin-treated rats showed increased survival rates as well as a better functional recovery of gait properties and bladder function. Histological results demonstrated reduced glial scar formation with keratin treatment and suggested a greater degree of beneficial remodeling and cellular influx. The data provided in this pilot study suggest the possibility of using a keratin-based treatment for SCI and warrant further investigation.

Keratin Biomaterials Improve Functional Recovery in a Rat Spinal Cord Injury Model

“…26 Influencing macrophage polarization is a novel strategy to manipulate the innate immune response following injury. Previously, keratin materials were demonstrated to influence polarization of M1 to M2 macrophage phenotypes, 16,17 although the exact mechanism remains unknown. Physiologic response after SCI varies slightly with size of the spinal cord and size of the cord-blood-barrier, which can lead to variation in treatment outcomes.…”

“…Influencing macrophage polarization is a novel strategy to manipulate the innate immune response following injury. Previously, keratin materials were demonstrated to influence polarization of M1 to M2 macrophage phenotypes, 16,17 although the exact mechanism remains unknown.…”

“…Recently, keratin biomaterials have been utilized for drug delivery, wound healing, and other tissue regeneration applications 13–15 . Although the mechanism is unclear, keratin biomaterials have been shown to induce macrophage polarization in THP-1 human monocytic cell derived macrophages 16,17 . Based on previous research utilizing keratin biomaterials for tissue repair, 18 the purpose of this study was to examine the effect of route of delivery and efficacy of a soluble keratin biomaterial to improve functional recovery and lesion healing in a rat contusion SCI model.…”

Natural and synthetic polymeric scaffolds used in peripheral nerve tissue engineering: Advantages and disadvantages

“…Hydrogel keratin consistently displayed a significant development in hind limb motor function improvement and on the other hand the histological study offers an increased cellular appearance. 95 Keratin can be easily electrospun in combination with other nonnatural polymers with stronger mechanical characteristics, enhancing their biocompatibility with excellent results. Hao et al, a group of researchers from china that they studied on Keratin nanoparticles-coating electrospun Polyvinyl alcohol nanofiber with electrospray technique with potential NTE application to improve the hydrophilicity and mechanical property.…”

Activation of Astrocytes <i>in Vitro</i> by Macrophages Polarized with Keratin Biomaterial Treatment

“…A new intervention being studied for SCI is keratin biomaterials. A keratin hydrogel has demonstrated efficacy in promoting greater recovery of gait and bladder functions following a rat hemisection injury [23]. It has also shown an ability to skew macrophage polarization toward a M2 phenotype and promote significant up-regulation of M2-associated cytokines like IL-10, while down-regulating M1-associated cytokines like IL-6 [24].…”