Peripheral Nerve Decellularisation Protocol for Allogeneic Transplantation: From Tissue Procurement to Banking.

Peripheral nerve injuries affect over one million individuals annually worldwide due to various causes such as trauma, metabolic disorders, and autoimmune diseases. While autologous nerve grafting remains the gold standard for treating large-gap nerve injuries, its limitations, including limited tissue availability, donor site morbidity, infection risk, and suboptimal functional recovery, have spurred interest in alternative approaches. Among these, allogeneic nerve grafting has emerged as a promising option, offering structural and functional advantages due to the native architecture of donor nerves. However, immune rejection due to histocompatibility antigens remains a significant challenge. Decellularisation protocols utilising mild detergents have shown the most promise in preserving the extracellular matrix's structural and regenerative properties while mitigating immunogenicity. The study aimed to adapt and validate a decellularisation protocol for human nerves within our tissue bank, adhering to European and national regulatory guidelines. The protocol, based on the cleanroom-compliant method previously developed by our group, was optimised to reduce tissue handling time and ensure regulatory compliance. Decellularised sural nerves were assessed for extracellular matrix preservation and sterility using European (EU) Pharmacopoeia and European Directorate for the Quality of Medicines & HealthCare (EDQM) guidelines. The results demonstrated the feasibility of producing high-quality acellular nerve allografts (ANAs) that are suitable for peripheral nerve repair, paving the way for cost-effective and widely accessible grafting solutions.