The introduction of neurotrophic factors into injured peripheral nerve sites is beneficial to peripheral nerve regeneration. However, neurotrophic factors are rapidly degraded in vivo and obstruct axonal regeneration when used at a supraphysiological dose, which limits their clinical benefits. Bioactive mimetic peptides have been developed to be used in place of neurotrophic factors because they have a similar mode of action to the original growth factors and can activate the equivalent receptors but have simplified sequences and structures. In this study, we created polydopamine-modified chitin conduits loaded with brain-derived neurotrophic factor mimetic peptides and vascular endothelial growth factor mimetic peptides (Chi/PDA-Ps). We found that the Chi/ PDA-Ps conduits were less cytotoxic in vitro than chitin conduits alone and provided sustained release of functional peptides. In this study, we evaluated the biocompatibility of the Chi/PDA-Ps conduits. Brain-derived neurotrophic factor mimetic peptide and vascular endothelial growth factor mimetic peptide synergistically promoted proliferation of Schwann cells and secretion of neurotrophic factors by Schwann cells and attachment and migration of endothelial cells in vitro. The Chi/PDA-Ps conduits were used to bridge a 2 mm gap between the nerve stumps in rat models of sciatic nerve injury. We found that the application of Chi/PDA-Ps conduits could improve the motor function of rats and reduce gastrocnemius atrophy. The electrophysiological results and the microstructure of regenerative nerves showed that the nerve conduction function and remyelination was further restored. These findings suggest that the Chi/PDA-Ps conduits have great potential in peripheral nerve injury repair.

Department of Orthopedics and Trauma,Peking University People's Hospital,Beijing,China;Key Laboratory of Trauma and Neural Regeneration,Ministry of Education,Beijing,China;National Center for Trauma Medicine,Beijing,China;Beijing Key Laboratory for Bioengineering and Sensing Technology,School of Chemistry and Biological Engineering,University of Science and Technology Beijing,Beijing,China

[1]Ci Li;Song-Yang Liu;Li-Ping Zhou;Tian-Tian Min;Meng Zhang;Wei Pi;Yong-Qiang Wen;Pei-Xun Zhang-.Polydopamine-modified chitin conduits with sustained release of bioactive peptides enhance peripheral nerve regeneration in rats)[J].中国神经再生研究（英文版）,2022(11):2544-2550

supraphysiological,stumps

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