Electroactive chitosan-aniline pentamer hydrogel for peripheral nerve regeneration

Electroactive hydrogels could guide the regeneration of nerves and promote their functional recovery. An aniline pentamer-crosslinked chitosan (CS-AP) hydrogel with better electroactivity and degradation was fabricated by the carbodiimide method, and then injected into the repair site of sciatic nerve damage, with its gelation time, tensile strength, and conductivity reaching 35 min, 5.02–6.69 MPa, and from 2.97 × 10⁻⁴ to 3.25 × 10⁻⁴ S·cm⁻¹, respectively, due to the cross-linkage and well-distribution of AP. There was better cytocompativility of CS-AP hydrogel on nerve cells. The results of the in vivo repair indicated that CS-AP10 hydrogel induced the capillaries formation and the repair of sciatic nerve defect, and re-innervated gastrocnemius muscle in the CS-AP10 group were obviously better than other experimental groups, due to the electroactivity of CS-AP and its degradation into fragments. These results indicated the potential application of CS-AP hydrogel in the regeneration and function recovery of peripheral nerve injury.