Electroactive polymers and coatings

Abstract

Electroactive polymers (EAPs) and coatings (EACs) provide an expanding and progressive frontier for responsive drug delivery and the design of biomedical devices. EAPs possess the distinctive propensity to undergo a change in shape and/or size following electrical current activation. Current interest in EAPs and EACs extends to use in controlled drug delivery applications, where an "on-off" mechanism for drug releases would be optimal, as well as application in a biomedical devices and implants. This chapter explores and molecularly characterizes various EAPs such as polyaniline, polypyrrole, polythiophene, and polyethylene, which can ultimately be incorporated into responsive hydrogels in conjunction with, for example, a desired bioactive, to obtain a stimulus-controlled bioactive release system, which can be actuated by the patient, for enhanced specificity. The institution of hybrids of conducting polymers and hydrogels has also been subjected to increasing investigation as soft EACs, which have been applied, for example, in the improvement of the mechanical and electrical performance of metallic implant electrodes. The various interconnected aspects of EAP-based systems, including their synthesis, proposed modus operandi, physical properties, as well as functionalization approaches for enhancing the performance of these systems, are delineated. The use and comparison of these EAPs and EACs alone, and in conjunction with hydrogels, is further elaborated, together with strategies for integrating electroactive components and hydrogels. Approaches for modeling and explaining the proposed modus operandi of these systems are delineated. A critical review of diverse biomedical systems implementing EAPs and EACs having application in the pharmaceutical and medical industry, specifically, is provided, highlighting their applications, potential advantages, and possible limitations. Ultimately, this chapter illuminates innovative approaches for enabling EAP- and EAC-based systems to attain their full clinical potential.