Optically transparent and permeable microarrays for cellular assays

Abstract

A new class of porous membrane, porous nanocrystalline silicon (pnc‐Si), offers a unique combination of nanoscale thickness (< 100 nm) and tunable pore sizes in the range of 5 to 100 nm. Pnc‐Si is ideally suited for small volume cell culture devices because the nanometer thinness and high permeability enable rapid diffusion of low abundance species with minimal loss. Two cell types can be cultured within tens of nanometers of one another, allowing cell‐cell communication and other microenvironment‐dependent co‐culture studies. We have developed an approach to create microwells on these suspended membranes using photopolymerized PEG. Cells grown within these microwells are spatially separated, but can readily communicate through the membrane with a feeder cell layer or with neighboring microwells due to PEG permeability. Additionally, pnc‐Si membranes are extraordinarily transparent to light, permitting their use in image‐based, high‐content screening assays. Sources of Funding: NIH and RIT.