3D Bioprinted Cell-laden GrooveNeuroTube: A Multifunctional Platform for Ex Vivo Neural Cell Migration and Growth Studies

Extensive peripheral nerve injuries often lead to the loss of neurological function due to slow regeneration and limited recovery over large gaps. Current clinical interventions, such as nerve guidance conduits (NGCs), face challenges in creating biomimetic microenvironments that effectively support nerve repair. In this study, we designed the GrooveNeuroTube, composed of a hyaluronic acid methacrylate and gelatin methacrylate (HAMA-GelMA) hydrogel, incorporating active agents (growth factors and antibacterial agent) encapsulated within an NGC conduit made of 3D-printed PCL grid fibers. This bioengineered conduit demonstrated high cytocompatibility (>90%) and extended degradability (over 60 days). In vitro studies showed that GrooveNeuroTube significantly promoted the proliferation and migration of dorsal root ganglion (DRG) neuronal cells, 3D bioprinted at the far ends of the conduit to imitate a proximal nerve injury as a novel ex vivo model. A long-term culture of up to 60 days was employed to better mimic in vivo conditions. We then used this model to test the effects of pulsed electromagnetic field (PEMF) stimulation on neural tissue development and integration. Analysis revealed that neurite length was significantly greater in cells exposed to PEMF stimulation, with more elongated neurites (38%). After 60 days in culture, GrooveNeuroTube showed cell migration reaching 7.2 mm, representing a 32% increase compared to the GF-only group and a 105% increase compared to the no-growth-factor condition. These results confirm that the GrooveNeuroTube system can effectively support sustained neural cell migration and maturation over extended periods, proving a new technology for testing peripheral nerve injury ex vivo.