Generation of Tissue Engineered Nerve Grafts from GalSafe Porcine Neurons

PROJECT SUMMARY Tissue engineered medical products have tremendous promise to address the currently irreparable effects of neurotrauma and/or neurodegenerative diseases. Axonova Medical’s lead product, the tissue engineered nerve graft (TENG), is a bioactive “living scaffold” proven to promote rapid nerve regeneration and functional restoration when implanted to repair major peripheral nerve injury (PNI). Implementing living neuronal cells as the starting biomass, Axonova routinely biomanufactures TENGs comprised of living, long, aligned axon tracts through the proprietary process of axon “stretch-growth”. To date, TENGs have been shown to consistently promote host axon regeneration and improve functional recovery compared to current clinical practices in both small and large animal models of PNI, including the repair of 5 cm segmental defects. In order to move to a manufacturing- compliant biomass, Axonova has partnered with Revivicor to generate GalSafe® TENGs using their genetically engineered porcine neurons to mitigate a host immune response upon eventual transplantation in humans. Through the Phase I efforts, GalSafe® TENGs were successfully stretch-grown to create products at lengths of 1 cm, 3 cm, and 5 cm with a health and axon density that met or exceeded established quality benchmarks. Moreover, 1 cm TENGs were transplanted into a rodent PNI model to demonstrate regenerative efficacy, revealing that GalSafe® TENGs survived as well as actively drove host axonal regeneration via the proprietary mechanism-of-action of TENGs, referred to as axon facilitated axon regeneration (AFAR). Along with choosing a safe and readily available starting biomass, other product development challenges include biopreservation and quality assurance criteria to allow increased shelf life, transportation, and maintained efficacy of the product. Accordingly, the current Phase II SBIR program addresses a key facet of clinical grade biomanufacturing, specifically the validation of an effective storage protocol and release criteria ensuring product health, sterility, and potency. TENGs will be biofabricated from a cGMP-compliant cell source (GalSafe® porcine neurons), cold- stored using a cGMP-compliant preservation protocol, and then tested in small and large animal models of PNI to demonstrate regenerative efficacy. Specifically, Axonova will systematically complete the objectives of this program across 3 Specific Aims: (1) determine the efficacy of fresh GalSafe® TENGs in an established porcine PNI model; (2) effectively biopreserve GalSafe® TENGs to increase shelf-life and validate non-invasive release criteria; and (3) determine the potency and efficacy of biopreserved GalSafe® TENGs in vivo in rodent and porcine PNI models. This program addresses a major challenge in the translation of next-generation tissue engineered medical products by validating manufacturing, storage and release criteria for a living biological product to enable eventual testing in humans. The ability to store and distribute GalSafe® TENGs as an “off-the- shelf” product will vastly increase commercial potential by reducing costs and expanding patient access, thereby improving recovery and quality of life for patients suffering from the debilitating effects of major PNI.