A shape-persistent plasticine-like conductive hydrogel with self-healing properties for peripheral nerve regeneration

In recent years, electrically conductive hydrogel-based nerve guidance conduits (NGCs) have yielded promising results for treating peripheral nerve injuries (PNIs). However, developed ones are generally pre-manufactured and exhibit a limited ability to achieve good contact with nerve tissue with irregular surfaces. Herein, we developed a plasticine-like electrically conductive hydrogel consisting of gelatin, conducting polypyrrole , and tannic acid (named GPT) and assessed its ability to promote peripheral nerve regeneration. The shape-persistent GPT hydrogel exhibited good self-healing properties and could easily be molded to form a conduit that could match any injured nerve tissue. Their electrical properties could be tuned by changing the PPy concentration. In vitro , the improved conductivity of the hydrogel promoted dorsal root ganglion (DRG) axonal extension. More importantly, we found that the GPT hydrogel enhanced axonal regeneration and remyelination in vivo , preventing denervation atrophy and enhancing functional recovery in a mice model of sciatic nerve injury. These results suggest that our plasticine-like NGC has huge prospects for clinical application in the repair of PNI.