Fabrication of ECM protein coated hollow collagen channels to study peripheral nerve regeneration

Peripheral nerve injury is a prevalent clinical problem that often leads to lifelong disability and reduced quality of life. Although peripheral nerves can regenerate, recovery after severe injury is slow and incomplete. The current gold standard treatment, autologous nerve transplantation, has limitations including donor site morbidity and poor functional outcomes, highlighting the need for improved repair strategies. We developed a reproducible in vitro hollow channel collagen gel construct to investigate peripheral nerve regeneration (PNR) by exploring the influence of key extracellular matrix (ECM) proteins on axonal growth and regeneration. Channels were coated with ECM proteins: collagen IV, laminin, or fibronectin and seeded with dorsal root ganglia (DRG) collected from E16 rat embryos to compare the ability of the ECM proteins to enhance axonal growth. Robust axonal extension and Schwann cell (SC) infiltration were observed in fibronectin-coated channels, suggesting its superiority over other ECM proteins. Differential effects of ECM proteins on axons and SCs indicated direct growth stimulation beyond SC-mediated guidance. In vitro laceration injury modeling further confirmed fibronectin's superior pro-regenerative effects, showcasing its potential in enhancing axonal regrowth post-injury. Advancing in vitro modeling that closely replicates native microenvironments will accelerate progress in overcoming the limitations of current nerve repair approaches.