Highly permeable membranes for live cell imaging of co‐cultures

A new class of porous membrane, porous nanocrystalline silicon (pnc‐Si) has been fabricated that is unique in its combination of nanoscale thickness (5–30 nm) with macroscopic, yet robust, millimeter‐scale lateral dimensions and tunable pore sizes in the range of 5 to 100 nm. We have reported permeability values as much as two orders of magnitude greater than conventional track‐etched and ultrafiltration membranes. Pnc‐Si offers a physical barrier for cell co‐culture and drug permeability applications while minimizing the resistance to diffusion of small molecules. Unlike conventional polymeric membranes that are microns in thickness, the thinness of the membrane results in nearly optical transparency, enabling high‐resolution imaging of cells on both the top and the bottom of the membrane. In addition, membrane surface treatments can be used to control degradation from 1 to 30 days yielding a two‐dimensional degradable scaffold. We have used this membrane to develop a blood‐brain barrier model resulting in greater transendothelial resistance (TEER) than a conventional track‐etched membrane. Sources of Funding: SiMPore, NYSTAR, NIH.