*Article* **Electrochemically Enhanced Drug Delivery Using Polypyrrole Films**

**Sayed Ashfaq Ali Shah 1,2,†, Melike Firlak 1,†, Stuart Ryan Berrow 1, Nathan Ross Halcovitch 1, Sara Jane Baldock 1, Bakhtiar Muhammad Yousafzai 3, Rania M. Hathout 1,4,5,6 and John George Hardy 1,7,\***


Received: 1 June 2018; Accepted: 26 June 2018; Published: 1 July 2018

**Abstract:** The delivery of drugs in a controllable fashion is a topic of intense research activity in both academia and industry because of its impact in healthcare. Implantable electronic interfaces for the body have grea<sup>t</sup> potential for positive economic, health, and societal impacts; however, the implantation of such interfaces results in inflammatory responses due to a mechanical mismatch between the inorganic substrate and soft tissue, and also results in the potential for microbial infection during complex surgical procedures. Here, we report the use of conducting polypyrrole (PPY)-based coatings loaded with clinically relevant drugs (either an anti-inflammatory, dexamethasone phosphate (DMP), or an antibiotic, meropenem (MER)). The films were characterized and were shown to enhance the delivery of the drugs upon the application of an electrochemical stimulus in vitro, by circa (ca.) 10–30% relative to the passive release from non-stimulated samples. Interestingly, the loading and release of the drugs was correlated with the physical descriptors of the drugs. In the long term, such materials have the potential for application to the surfaces of medical devices to diminish adverse reactions to their implantation in vivo.

**Keywords:** conducting polymers; electroactive polymers; medical devices; drug delivery; anti-inflammatory; antibiotic
