Conducting Polymers for <i>In Situ</i> Drug Release Triggered via Electrical Stimulus

Conducting polymers (CPs) are a unique type of polymer that exhibit metal-like features. Their ability to undergo reversible redox conversion, in addition to their optical and electronic properties, have enhanced the use of CPs in the development of advanced materials for technological applications, mainly focused on the energy field. However, during the last 15 years, increasing interest has been focused on biomedical and pharmaceutical applications of CPs. The development of CPs-based biocomposites for drug release takes advantage of the reversible redox behavior of CPs, allowing an accurate control of therapeutic agents and other bioactive molecule release profiles, triggered by an external stimulus. This Review discusses the development of drug delivery systems based on CPs. Encompassing intrinsic features, such as physicochemical aspects, electrical ability, and conducting mechanism involved in the release of therapeutic agents driven by electrochemical stimuli. A detailed description of the electrochemical drug-loading, methods of fabrication, and characterization of innovative CPs-based drug delivery platforms is provided. A comparative analysis of polymerization methods is presented to guide researchers in the method selection. Finally, application of CPs on drug release, and cell response, is discussed in terms of their intrinsic properties, which enhance their pharmaceutical applications.