On-demand drug delivery bioelectronics through a water-processable low dimensional highly conductive MXene layer.

On-demand drug delivery holds great promise to optimize pharmaceutical efficacy while minimizing the side effects. However, existing on-demand drug delivery systems often require complicated manufacturing processes that preclude their wide implementation of a broad range of drugs. In this work, we demonstrate the introduction of MXene-coated microneedles (MNs) into bioelectronics for digitally controllable gate-valve drug delivery. MXenes, featuring high electronic conductivity, excellent biocompatibility, and solution processibility, enable low-cost scalability for printable bioelectronics. In an electrolytic state (e.g., body fluid), the coated MXene is oxidized and desorbed due to redox reactions caused by electrical bias, allowing the underlying drug to be controllably released. The MXene-incorporated drug delivery system not only demonstrates excellent biocompatibility and operational stability, but also features low-cost construction and sustainable usage. Besides, these MXene-coated MNs allow both on-demand transformation and local-region customization, further increasing the structural versatility and capability of multidrug delivery systems.

Orbit symmetry breaking in MXene implements enhanced soft bioelectronic implants.

Bioelectronic implants featuring soft mechanics, excellent biocompatibility, and outstanding electrical performance hold promising potential to revolutionize implantable technology. These biomedical implants can record electrophysiological signals and execute direct therapeutic interventions within internal organs, offering transformative potential in the diagnosis, monitoring, and treatment of various pathological conditions. However, challenges remain in improving excessive impedance at the bioelectronic-tissue interface and thus the efficacy of electrophysiological signaling and intervention. Here, we devise orbit symmetry breaking in MXene (a low-cost scalability, biocompatible, and conductive two dimensionally layered material, which we refer to as OBXene), which exhibits low bioelectronic-tissue impedance, originating from the out-of-plane charge transfer. Furthermore, the Schottky-induced piezoelectricity stemming from the asymmetric orbital configuration of OBXene facilitates interlayered charge transport in the device. We report an OBXene-based cardiac patch applied on the left ventricular epicardium of both rodent and porcine models to enable spatiotemporal epicardium mapping and pacing while coupling the wireless and battery-free operation for long-term real-time recording and closed-loop stimulation.