Low voltage electric field governs fibrous silk electrogels

Abstract

Silk fibroin gels, formed with electric fields, have been studied and potential utility in medical materials. However, silk electrogels with controllable nanofiber network morphology have rarely been reported. In this work, low voltage electric field was developed to control the nanofiber network morphology formation and resulting electrogelation of silk fibroin aqueous solution, inducing a transition from an overall protein structure that is initially rich in random coil to one that is rich in β-sheet. Under low voltage (3–24 V), solution concentration (≤5.0 wt%), and neutral, alkaline conditions, silk fibroin fibrous electrogels were easily formed. At the same time, compression test result exhibited the compressive stress of silk fibroin fibrous electrogels was 250.17 ± 16.50 kPa at dry state, which formed from silk fibroin concentration 3.0 wt%. Moreover, the recovery rate of electrogels can reach more than 50% after 10 compression-recovery circles, exhibiting excellent flexibility. In addition, silk fibroin electrogels loaded cefixime drugs have obvious antibacterial effect against Staphylococcus aureus and Escherichia coli than commercial medical band-aids. Drug-loaded silk fibroin fibrous electrogels supported mouse embryonic fibroblasts 3 T3 cells attachment and proliferation over 7 days. This study offers an effective approach to design and synthesis of new dressings.

Keywords

• Silk fibroin
• Electrogelation
• Electric field
• Wound dressings