SELECTIVE SURFACE COATING IN CLOSED MICROFLUIDIC ARRAYS FOR CELL ASSAYS

A microfluidic array format is often used to increase the throughput of cell assays.For assays with adherent cells, the microfluidic surfaces require surface treatment for cell survival and function.However, uniform surface treatment results in cell migration out of the arrays, preventing accurate cell tracking during an assay.Thus, there is a need for selective surface coating to aid in site-specific patterning of adherent cells.While micro-contact printing is the most common surface patterning technique [1], this technique must be performed on open surfaces, increasing contamination risk for cell culture.Photopatterning techniques have been developed for surface patterning of bonded microfluidic devices [2], but they require complex fabrication and expensive substrates.Capillary-based patterning is much simpler as it relies on fluid transport in microchannels to guide the delivery of functional molecules.One platform utilizes capillary forces to pattern two populations of cells in one dimension along a microchannel [3].To our knowledge, most capillary-based platforms are not adequate for twodimensional patterning.