Mesenchymal stem cell growth on silicon nanowires made by metal-assisted chemical etching

D. Ratchford, J. Morabito, P.A. Fulmer, J. Yeom, J.W. Baldwin, T.J.O. Shaughnessy, C.R. Field, S.P. Mulvaney, P.E. Pehrsson
U.S. Naval Research Laboratory, US

Keywords: mesenchymal stem cell, silicon nanowires

Summary:

Vertically aligned arrays of silicon nanowires (SiNWs) provide a multifunctional platform for controlling stem cell differentiation with nanoscale topography. It has been shown that the spacing between the NWs can influence stem cell morphology, and by using NWs in an array to penetrate the cell membrane, biomolecules can be delivered into the interior of a cell. In addition to the nanoscale topography, surface chemistry plays a critical role in determining cell fate. In this work, we use metal-assisted chemical etching to produce porous SiNWs with different surface treatments for controlling mesenchymal stem cell growth. SiNWs were fabricated with a variety of diameters, pitch, and surface treatments including native oxide, poly-D-lysine and laminin, and atomic layer deposition (ALD) of Al2O3. The growth of mesenchymal stem cells was characterized up to 2 weeks after cell plating. While UV-ozone treated SiNWs with a native oxide showed almost no mesenchymal stem cell survival, SiNWs coated with ALD Al2O3 yielded survival rates similar to the control substrates. These results will be discussed in light of our goal to understand the role of SiNW geometry and surface chemistry in determining stem cell growth.