4D Oriented Dynamic Scaffold for Promoting Peripheral Nerve Regeneration and Functional Recovery

Neurological function recovery after peripheral nerve injury (PNI) is exceptionally challenging, chiefly because neurons cannot efficiently proliferate, differentiate, and form regenerated axons to pass through the defect region expeditiously and transmit neurological signals. In this study, a four-dimensional (4D) oriented dynamic scaffold is constructed based on shape memory polymer (SMP), which can regulate spatiotemporally controllable neuronal early adequate proliferation, subsequently effective differentiation and axon formation by synergizing the on-demand microtopography and deformation force-based mechanical stimuli (DFMS). This dynamic scaffold can accelerate the restoration of large segmental nerve defects, elevate the neural signaling efficiency by 60% compared with static scaffold, and finally form the functionalized robust regenerating nerve fascicles with comparable therapeutic effects on autologous nerve transplantation. Furthermore, the crucial role of Piezo1/Camk2b modulated neuronal differentiation and axon extension is also revealed through deep transcriptomic analysis. In summary, the 4D oriented dynamic scaffold can precisely and remotely regulate neuronal behavior and fate in a non-invasive way, which has excellent potential for clinical application in peripheral nerve restoration. Dynamic microtopography and mechanical stimulation are two fruitful strategies to regulate neuronal proliferation, differentiation, and axon formation. Taking them into a sciatic nerve defect model, a 4D oriented dynamic scaffold is constructed by shape memory polymer, which can accelerate peripheral nerve regeneration and functional recovery. Piezo1/Camk2b plays a crucial role in this process.image