Development of Tissue Engineered Neuromuscular Interfaces from GalSafe Neurons.

PROJECT SUMMARY Major peripheral nerve injury (PNI) is classified as an injury with a long defect (≥3cm) or occurring proximally, requiring long regenerative distances of the host nerve to distal structures (distal nerve, target muscle, etc.). These features result in minimal, if any, functional regeneration as the distal nerve and muscle often degenerate before the host nerve is able to reinnervate these structures due to inherently slow regeneration rates. Since current standard clinical practices delay repairing nerve injuries until the patient (in cases of polytrauma) or the injury site is stabilized, functional recovery is often extremely limited. In order to maintain the innervation capability of nerves and muscles following injury, the team at Axonova Medical has developed a proxy for these degenerating axons to maintain or “babysit” the distal structures until the host axons are able to reinnervate the distal targets. This product, the tissue engineered neuromuscular interface (TE-NMI), consists of axon tracts spanning a discrete population of neurons within a hydrogel column. Notably, the diameter of TE-NMIs is designed to be on the scale of micrometers, making them easily injectable to facilitate incorporation into current standard of care practices in the clinic. In pre-clinical rodent studies, TE-NMIs have been seen to extend axons into distal structures post implantation, resulting in babysitting of distal nerve and muscle, therefore keeping it receptive to eventual host axon reinnervation. Previously, laboratory-grade TE-NMIs have been fabricated using primary rat and porcine neurons as well as human induced pluripotent stem cell (iPSC)-derived neurons. In this study, a clinical product will be developed and characterized using GalSafe® neurons as the starting biomass. GalSafe® tissue is an FDA-approved xenogeneic source produced by Revivicor, Inc. Revivicor has genetically engineered swine to produce tissue lacking a carbohydrate, known as -galactosidase, that is known to play a key role in eliciting an immune response in humans. GalSafe® neurons are harvested from the spinal cords of GalSafe® swine embryo, and is the chosen biomass for Axonova’s other product, tissue engineered nerve grafts (TENGs). For this proposal, initial characterization and a preliminary in vivo study to determine the efficacy of TE-NMIs to promote recovery in a chronic axotomy model in swine will be carried out. Successful execution of these studies will accelerate preclinical safety and efficacy studies and will be incorporated in Axonova’s IND application. Overall, TE-NMIs hold promise in transforming the field of nerve repair by significantly increasing the clinical window for PNI repair.