Spatially Controlled, Wirefree, Drug Release along a Single PEDOT Film

A wire-free bipolar electrochemical strategy for spatially resolved release of encapsulated molecules from within a conducting polymer film is described. Thin electrodeposited PEDOT films were loaded with fluorescein and exposed to an externally generated electric field (∼0.6 V cm^-1), creating a longitudinal potential gradient within the PEDOT film. The resulting spatial variation in PEDOT oxidation state modulates fluorescein release, producing programmable, region-dependent release along the single continuous film. This enables directional drug elution (low-to-high release across the film) without the need for wires, embedded electronics, or segmented reservoirs. This, wirefree, spatially nonuniform drug release enables applications where the drug needs to be delivered preferentially to one tissue, e.g., to reduce irritation or toxicity to adjacent healthy tissue, e.g., ocular inserts, periodontal chips, wound dressings, stents, orthopedic implants etc., where a drug release is only beneficial on one area of the device. Moreover, reconfiguring the external field distribution provides a route to translate the release zone over time enabling dynamic targeting postdeployment.