Wireless, spatially controlled in-situ methotrexate drug encapsulation and release from PEDOT films

Here, we demonstrate the in-situ wireless doping and release of methotrexate from the conducting polymer film poly(3,4-ethylenedioxythiophene), PEDOT. PEDOT films were electrodeposited and simultaneously doped with methotrexate. The electric field in solution induces a potential gradient along the bipolar electrode leading to thicker films at the anodic pole, and correspondingly, a substantial enhancement in methotrexate loading compared to conventional electrodeposition. In release mode, this approximately linear distribution in PEDOT oxidation states enables spatial control of methotrexate loading and produces regioselective release, with the total moles of methotrexate encapsulated depending on the PEDOT layer thickness. This substantial enhancement in loading capacity addresses a key limitation in conventional systems, establishing a proof-of-concept platform for remote drug loading and controlled therapeutic delivery from conductive devices, with the potential to strive towards rechargeable, implantable systems.