Microfluidic Control of Microparticle Diffusion through A Semi-Permeable Matrix

In this study, microparticle flow and diffusion was observed through unique channel geometries patterned into a semi-permeable hydrogel matrix. The microfluidic channel geometry was designed to mimic the bifurcations of vasculature. First, the appropriate photomasks were created and used to fabricate a device master using photolithography. The master was used to emboss a cavity into a PDMS slab, which was adhered to a glass slide using plasma treatment. The inner PDMS surface was then subjected to surface chemical modification using a silane-based monolayer. To complete the fabrication of the device, the unique channel configuration was then patterned into an acrylated PEG hydrogel within the cavity. Finally, flow of microparticle-laden media through the microchannels and diffusion of microparticles into the hydrogel was observed. These observations have implications for drug delivery and fluid mechanics phenomena involving tumor cells.