The use of microneedles has facilitated the painless localized delivery of drugs across the skin. However, their efficacy has been limited by slow diffusion of molecules and often requires external triggers. Herein, an autonomous and degradable, active microneedle delivery platform is introduced, employing magnesium microparticles loaded within the microneedle patch, as the built-in engine for deeper and faster intradermal payload delivery. The magnesium particles react with the interstitial fluid, leading to an explosive-like rapid production of H2 bubbles, providing the necessary force to breach dermal barriers and enhance payload delivery. The release kinetics of active microneedles is evaluated in vitro by measuring the amount of IgG antibody (as a model drug) that passed through phantom tissue and a pigskin barrier. In vivo experiments using a B16F10 mouse melanoma model demonstrate that the active delivery of anti-CTLA-4 (a checkpoint inhibitor drug) results in greatly enhanced immune response and significantly longer survival. Moreover, spatially resolved zones of active and passive microneedles allow a combinatorial rapid burst response along with slow, sustained release, respectively. Such versatile and effective autonomous dynamic microneedle delivery technology offers considerable promise for a wide range of therapeutic applications, toward a greatly enhanced outcome, convenience, and cost.

中文翻译：

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内置主动微针贴片，具有增强的自主给药功能。

微针的使用促进了药物在皮肤上的无痛局部输送。然而，它们的功效受到分子扩散缓慢的限制，并且通常需要外部触发。在此，引入了一种自主且可降解的主动微针递送平台，采用装载在微针贴片内的镁微粒作为内置引擎，以实现更深、更快的皮内有效负载递送。镁颗粒与间质液发生反应，导致爆炸般快速产生氢气气泡，提供突破真皮屏障和增强有效负载输送所需的力量。通过测量穿过模型组织和猪皮屏障的 IgG 抗体（作为模型药物）的量，在体外评估活性微针的释放动力学。使用 B16F10 小鼠黑色素瘤模型的体内实验表明，主动递送抗 CTLA-4（一种检查点抑制剂药物）可大大增强免疫反应并显着延长生存期。此外，主动和被动微针的空间分辨区域分别允许组合的快速爆发响应和缓慢、持续的释放。这种多功能且有效的自主动态微针输送技术为广泛的治疗应用提供了巨大的希望，从而大大提高了结果、便利性和成本。