Digital electronics-free implantable drug delivery system for on-demand therapy

Electronic-free implantable drug delivery systems (IDDSs) enables direct and biocompatible drug delivery at the lesion site, holding immense potential to treat a variety of diseases. However, this electronics-free feature prevents such systems from utilizing conventional electromechanical or microelectromechanical technologies, making the controllability of drug release inherently deficient. To address this issue, we propose a digital IDDS for on-demand local drug delivery in vivo. Quantitative drugs are encapsulated in the drug capsules by using 3D printing to keep the drug in an accurate and viable state. These capsules are then stored in a multi-reservoir implantable drug delivery device (IDDD) and implanted subcutaneously. The IDDD can be magnetically actuated by a robot arm for sequential drug release when required. A noninvasive sensing strategy combining magnetic and force/torque signals is proposed to perceive the pose of the IDDD and the drug delivery state of the drug capsules. Digital drug release is achieved in vitro and in vivo experiments. The experimental results on the animal model of disuse osteoporosis showed that compared with systemic injection and local sustained-release methods, our approach can produce better therapeutic effects with lower doses. This innovative IDDS holds potential to realize automated and efficient therapy in clinic settings. © 2024 Elsevier B.V.