Nanocomposite Gold-Silk Nanofibers

Abstract

Cell-biomaterial interactions can be controlled by modifying the surface chemistry or nanotopography of the material, to induce cell proliferation and differentiation if desired. Here we combine both approaches in forming silk nanofibers (SNFs) containing gold nanoparticles (AuNPs) and subsequently chemically modifying the fibers. Silk fibroin mixed with gold seed nanoparticles was electrospun to form SNFs doped with gold seed nanoparticles (SNF[subscript seed]). Following gold reduction, there was a 2-fold increase in particle diameter confirmed by the appearance of a strong absorption peak at 525 nm. AuNPs were dispersed throughout the AuNP-doped silk nanofibers (SNFs[subscript Au]). The Young’s modulus of the SNFs[subscript Au] was almost 70% higher than that of SNFs. SNFs[subscript Au] were modified with the arginine-glycine-aspartic acid (RGD) peptide. Human mesenchymal stem cells that were cultured on RGD-modified SNF[subscript Au] had a more than 2-fold larger cell area compared to the cells cultured on bare SNFs; SNF[subscript Au] also increased cell size. This approach may be used to alter the cell–material interface in tissue engineering and other applications.