3D printed electro-responsive system with programmable drug release

Abstract

Precision medicine is the next frontier in pharmaceutical research, aiming to improve the safety and efficacy of therapeutics for patients. The ideal drug delivery system (DDS) should be programmable to provide real-time controlled delivery that is personalised to the patient's needs. However, little progress has been made in this domain. Herein, we combined two cutting-edge technologies, conductive polymers (CPs) and three-dimensional (3D) printing, to demonstrate their potential for achieving programmable controlled release. A DDS was formulated where the CP provided temporal control over drug release. 3D printing was used to ensure dimensional control over the design of the DDS. The CP used in this study is known to be fragile, and thus was blended with thermoplastic polyurethane (TPU) to achieve a conductive elastomer with sound mechanical properties. Rheological and mechanical analyses were performed, where it was revealed that formulation inks with a storage modulus in the order of 103–104 Pa were both extrudable and maintained their structural integrity. Physico-chemical analysis confirmed the presence of the CP functional groups in the 3D printed DDS. Cyclic voltammetry demonstrated that the DDS remained conductive for 100 stimulations. in vitro drug release was performed for 180 min at varying voltages, where a significant difference (p < 0.05) in cumulative release was observed between either ±1.0 V and passive release. Furthermore, the responsiveness of the DDS to pulsatile stimuli was tested, where it was found to rapidly respond to the voltage stimuli, consequently altering the release mechanism. The study is the first to 3D print electroactive medicines using CPs and paves the way for digitalising DDS that can be integrated into the Internet of Things (IoT) framework.