Palanisamy Barath, Goshi Noah, Seker Erkin
Department of Biomedical Engineering, University of California, Davis, CA 95616, USA.
Department of Electrical and Computer Engineering, University of California, Davis, CA 95616, USA.
Nanomaterials (Basel). 2021 Feb 16;11(2):498. doi: 10.3390/nano11020498.
Sustained release and replenishment of the drug depot are essential for the long-term functionality of implantable drug-delivery devices. This study demonstrates the use nanoporous gold (np-Au) thin films for in-plane transport of fluorescein (a small-molecule drug surrogate) over large (mm-scale) distances from a distal reservoir to the site of delivery, thereby establishing a constant flux of molecular release. In the absence of halides, the fluorescein transport is negligible due to a strong non-specific interaction of fluorescein with the pore walls. However, in the presence of physiologically relevant concentration of ions, halides preferentially adsorb onto the gold surface, minimizing the fluorescein-gold interactions and thus enabling in-plane fluorescein transport. In addition, the nanoporous film serves as an intrinsic size-exclusion matrix and allows for sustained release in biofouling conditions (dilute serum). The molecular release is reproducibly controlled by gating it in response to the presence of halides at the reservoir (source) and the release site (sink) without external triggers (e.g., electrical and mechanical).
药物储库的持续释放和补充对于可植入给药装置的长期功能至关重要。本研究展示了使用纳米多孔金（np-Au）薄膜实现荧光素（一种小分子药物替代物）在平面内从远端储库到给药部位的长距离（毫米级）传输，从而建立分子释放的恒定通量。在不存在卤化物的情况下，由于荧光素与孔壁之间强烈的非特异性相互作用，荧光素的传输可以忽略不计。然而，在存在生理相关浓度离子的情况下，卤化物优先吸附到金表面，使荧光素与金的相互作用最小化，从而实现平面内荧光素的传输。此外，纳米多孔膜作为一种固有的尺寸排阻基质，在生物污染条件（稀释血清）下能够实现持续释放。分子释放可通过响应储库（源）和释放部位（汇）处卤化物的存在进行门控，无需外部触发（如电和机械触发），从而可重复控制。
