A self-responsive insulin delivery system is highly desirable because of its high sensitivity dependent on blood glucose levels. Herein, a smart pH-triggered and glucose-mediated transdermal delivery system, insulin-loaded and ZnO quantum dots (ZnO QDs) capped mesoporous bioactive glasses (MBGs) integrated with microneedles (MNs), was developed to achieve control and painless administration. ZnO QDs as a promise pH-responsive switch were employed to cap the nanopores of MBGs via electrostatic interaction. The drug (insulin) and glucose-responsive factor (glucose oxidase/catalase, GO_x/CAT) were sealed into the pores of MBGs. GO_x/CAT in the MBGs could catalyze glucose to form gluconic acid, resulting decrease in the local pH. The ZnO QDs on the surface of the MBGs could be dissolved in the acidic condition, leading to disassembly of the pH-sensitive MBGs and then release of preloaded insulin from the MBGs. As a result of administration in a diabetic model, an excellent hypoglycemic effect and lower hypoglycemia risk were obtained. These results indicate that as-prepared pH-triggered and glucose-mediated transdermal delivery systems have hopeful applications in the treatment of diabetes.

中文翻译：

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微针与ZnO量子点封闭的介孔生物活性玻璃相集成，用于葡萄糖介导的胰岛素递送

由于其高灵敏度取决于血糖水平，因此非常需要一种自响应式胰岛素输送系统。在本文中，开发了一种智能的pH触发和葡萄糖介导的透皮递送系统，将胰岛素负载和ZnO量子点（ZnO QDs）封端的中孔生物活性玻璃（MBG）与微针（MNs）集成在一起，以实现控制和无痛给药。ZnO QD作为有希望的pH响应开关，可通过静电相互作用覆盖MBG的纳米孔。将药物（胰岛素）和葡萄糖反应因子（葡萄糖氧化酶/过氧化氢酶，GO _x / CAT）封入MBG的孔中。GO _XMBG中的/ CAT可以催化葡萄糖形成葡萄糖酸，从而导致局部pH降低。MBG表面上的ZnO QD可以在酸性条件下溶解，导致pH敏感MBG分解，然后从MBG中释放预载的胰岛素。通过在糖尿病模型中施用，获得了优异的降血糖作用和较低的低血糖风险。这些结果表明，制备的pH触发和葡萄糖介导的透皮递送系统在糖尿病的治疗中具有希望的应用。