Ionic Diode-Based Drug Delivery System

Drug delivery systems hold promise for delivering cytotoxic drugs by controlling the timing and location of the drug release. However, conventional delivery mechanisms often fall short of achieving spatiotemporally controlled yet sustained release, which is crucial for ensuring drug efficacy and minimizing impact on surrounding tissues. Here, an ionic diode-based drug delivery system is reported that is controlled by an electric potential and capable of releasing drugs at scales ranging from nanogram to microgram. The migrated drug is slowly but continuously diffused to the lesion through the hydrogel at the desired rate. The ionic diode provides flow-free drug delivery while minimizing unintended drug leakage over prolonged periods. Implanted in a freely moving tumor-bearing mouse model, the system filled with doxorubicin demonstrated superior anti-tumor efficacy and minimal off-target immune toxicity compared to the intratumoral injection of free doxorubicin. With its mechanically compliant and biocompatible components, the system offers a safe and readily translatable approach to patients with surgically unresectable tumors.