A robust, electrochemically driven microwell drug delivery system for controlled vasopressin release
Micro-electro-mechanical-system (MEMS) based implantable drug delivery devices represent a promising approach to achieving more precise dosing, faster release and better localization of therapeutic compounds than is possible with existing technology. Despite recent advancements, there remain challenges in being able to build systems that enable active control over the dose rate and release time, in a robust, low power but simple to fabricate package. Here we demonstrate an implantable microreservoir device that enables delivery of dose volumes as high as 15 μl using an electrochemically based transport mechanism. This approach allows for a significant reduction in the amount of time required for drug delivery as well as reducing the dependence on the external physiological conditions. We present the overall design, operating principle and construction of the device, and experimental results showing the volume transport rate as a function of the strength of the applied electric field. The concentration profile vs. time, the power consumption, and ejection efficiency are also investigated. To demonstrate the medical utility of the device we also characterize the in-vitro release of vasopressin.
KeywordsDrug delivery Microfluidics Electrochemical reaction Vasopressin Microwell
This work was supported by the Defense Advanced Research Project Agency, Microsystems Technology Office, Hybrid Insect MEMS (HI-MEMS) program, through the Boyce Thompson Institute for Plant Research. Distribution unlimited. Fundamental research exempt from prepublication controls. The authors would like to thank Donn Kim and Bernardo Cordovez for helpful discussions and technical assistances. The facilities used for this research include Nanoscale Science & Technology Facility (CNF) and Nanobiotechnology Center (NBTC) at Cornell University.
Supplementary movie 1 Electrochemical transport of 15 μl of vasopressin directly into air for the case of an applied potential of 12 V (MPG 3620 kb)
Supplementary movie 2 Electrochemical transport of 15 μl of vasopressin into PBS buffer for the case of an applied potential of 12 V (MPG 3934 kb)
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