Conducting polymer hydrogels for electrically responsive drug delivery

Electrically responsive drug delivery is an attractive approach for the localised, tuneable release of drugs to meet therapeutic demands. Conducting polymers and hydrogels have been explored individually as materials for drug delivery applications with hybrids of these two materials offering potential to extend the range and amount of drug delivered, thereby creating new opportunities to achieve real-world benefit. Although accurate and long-term on-demand release of drugs through conducting polymer hydrogels still presents challenges, these are promising materials for the next generation of electrically responsive drug delivery devices. Here we review the fabrication methods and properties of conducting polymer hydrogels, relevant to drug delivery. In addition, the mechanisms behind drug loading and release are discussed, and applications for these systems presented. The current state of the field is discussed, alongside future steps required to achieve successful translation of these materials to the clinic.