Configurable microfluidic platform for investigating therapeutic delivery from biomedical device coatings.

Advanced biomedical device coatings have shown significant promise in delivery of therapeutics (e.g., small-molecule drugs, proteins) for a wide range of medical interventions ranging from targeted cancer therapy to management of atherosclerosis. In order to accelerate the development of such coatings, there is a need for tools to investigate the loading capacity and release kinetics with high temporal resolution and in a variety of physiological conditions. To address this need, we report a microfluidic platform, where the coating on a substrate can be mounted onto the microchannel and the device can be configured in two physiologically-relevant modes: (i) flow-mode allows for monitoring the release from the coating in contact with a liquid flowing at a specific rate, modeling the case of a drug-eluting stent. (ii) Static-mode, where the channel is filled with a stationary gel, mimics the case of drug-eluting brain implant. We demonstrate the utility of the platform with a fluorescein-loaded nanoporous gold coating and monitor in real-time the release kinetics both under deionized water infusion and an agarose gel-filled channel via fluorescence microscopy coupled to a LabVIEW-based interface.