Flexible multilevel nonvolatile biocompatible memristor with high durability.

Current protein or glucose based biomemristors have low resistance-switching performance and require complex structural designs, significantly hindering the development of implantable memristor devices. It is imperative to discover novel candidate materials for biomemristor with high durability and excellent biosafety for implantable health monitoring. Herein, we initially demonstrate the resistance switching characteristics of a nonvolatile memristor in a configuration of Pt/AlOOH/ITO consisting of biocompatible AlOOH nanosheets sandwiched between a Indium Tin Oxides (ITO) electrode and a platinum (Pt) counter-electrode. The hydrothermally synthesized AlOOH nanosheets have excellent biocompatibility as confirmed through the Cell Counting Kit-8 (CCK-8) tests. Four discrete resistance levels are achieved in this assembled device in responsible to different compliance currents (ICC) for the set process, where the emerging multilevel states show high durability over 103 cycles, outperforming the protein-based biomemristors under similar conditions. The excellent performance of the Pt/AlOOH/ITO memristor is attributed to the significant role of hydrogen proton with pipe effect, as confirmed by both experimental results and density functional theory (DFT) analyses. The present results indicate the nonvolatile memristors with great potential as the next generation implantable multilevel resistive memories for long-term human health monitoring.

Biodegradable Nanoprodrugs: "Delivering" ROS to Cancer Cells for Molecular Dynamic Therapy.

Biodegradable nanoprodrugs, inheriting the antitumor effects of chemotherapy drugs and overcoming the inevitable drawback of side effects on normal tissues, hold promise as next-generation cancer therapy candidates. Biodegradable nanoprodrugs of transferrin-modified MgO2 nanosheets are developed to selectively deliver reactive oxygen species to cancer cells for molecular dynamic therapy strategy. The nanosheets favor the acidic and low catalase activity tumor microenvironment to react with proton and release nontoxic Mg2+ . This reaction simultaneously produces abundant H2 O2 to induce cell death and damage the structure of transferrin to release Fe3+ , which will react with H2 O2 to produce highly toxic ·OH to kill tumor cells.