Fabrication of conductive electrospun silk fibroin scaffolds by coating with polypyrrole for biomedical applications

Scaffolds constituted by micro and nanofibers of silk fibroin were obtained by electrospinning. Fibers of fibroin meshes were coated with polypyrrole (pPy) by chemical polymerization; chemical linkages between polymers were observed by SEM and IR spectroscopy. Mechanical resistance of the meshes was improved by polypyrrole coating. Furthermore, coated meshes present a high electroactivity allowing anion storage and delivery during oxidation/reduction reactions in aqueous solutions. Uncoated and pPy coated materials support the adherence and proliferation of adult human mesenchymal stem cells (ahMSCs) or human fibroblasts (hFb). The bioactivity of fibroin mesh overcomes that of the polypyrrole coated meshes. ► Silk fibroin meshes were chemically coated with polypyrrole. ► The electroactivity of the coated fibroin meshes to store and release anions was quantified. ► Molecular structures and mechanical properties of the materials were characterized. ► Adherence and proliferation of human cells (ahMSCs and hFb) were studied. ► Biocompatibility of polypyrrole coated and uncoated materials is discussed.