Fabrication and characterization of polyacrylamide/silk fibroin hydrogels for peripheral nerve regeneration

Various hydrogels have been used for repairing peripheral nerve injury; however, the silk fibroin (SF)-based hydrogels in peripheral nerve regeneration are still rarely reported. In this study, the SF/pAM hydrogels with different SF concentrations and ethanol treatment time were developed by solution blending and in situ radical polymerization. The physiochemical properties of composite hydrogels were measured, the cytotoxicity of hydrogels was evaluated by L929 fibroblasts, and the effect on peripheral nerve regeneration was evaluated via Schwann cells culture in vitro. The results showed that the physiochemical properties of SF/pAM hydrogels could be changed by varying SF concentration and ethanol treatment time, and the mechanical property was enhanced with increasing SF concentration, while the presence of SF in pAM hydrogels and ethanol treatment does not affect hydrogels structure in per se. All the composite hydrogels displayed no obvious cytotoxicity, while the SF/pAM composite hydrogels with 10% SF and 60-min ethanol treatment could obviously accelerate the attachment and proliferation of Schwann cells. Therefore, the SF/pAM composite hydrogels possessed the beneficial properties required for in situ cell scaffolding and may have potential application in peripheral nerve regeneration.