Department of Dentistry-Biomaterials, Radboud University Medical Center, Philips van Leydenlaan 25, Nijmegen 6525 EX, The Netherlands.
Department of Preventive Dentistry, Academic Center for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam 1081 LA, The Netherlands.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):12018-12029. doi: 10.1021/acsami.9b21808. Epub 2020 Feb 25.
Electrophoretically deposited (EPD) polymer-based coatings have been extensively reported as reservoirs in medical devices for delivery of therapeutic agents, but control over drug release remains a challenge. Here, a simple but uncommon assembly strategy for EPD polymer coatings was proposed to improve drug release without introducing any additives except the EPD matrix polymer precursor. The added value of the proposed strategy was demonstrated by developing a novel EPD silk fibroin (SF) coating assembled from pre-assembled SF nanospheres for an application model, that is, preventing infections around percutaneous orthopedic implants via local delivery of antibiotics. The EPD mechanism of this nanosphere coating involved oxidation of water near the substrate to neutralize SF nanospheres, resulting in irreversible deposition. The deposition process and mass could be easily controlled using the applied EPD parameters. In comparison with the EPD SF coating assembled in a conventional way (directly obtained from SF molecule solutions), this novel coating had a similar adhesion strength but exhibited a more hydrophobic nanotopography to induce better fibroblastic response. Moreover, the use of nanospheres as building blocks enabled 1.38 and 21 times enhancement on the antibiotic release amount and time (of 95% maximum dug release), respectively, while retaining drug effectiveness and showing undetectable cytotoxicity. This unexpected release kinetics was found attributable to the electrostatic and hydrophobic interactions between the drug and nanospheres and a negligible initial dissolution effect on the nanosphere coating. These results illustrate the promising potential of the pre-assembled strategy on EPD polymer coatings for superior control over drug delivery.
电泳沉积（EPD）聚合物基涂层已被广泛报道为医疗设备中的储库，用于输送治疗剂，但控制药物释放仍然是一个挑战。在这里，提出了一种简单但不常见的 EPD 聚合物涂层组装策略，旨在改善药物释放，而无需引入任何添加剂，除了 EPD 基质聚合物前体。所提出策略的附加值通过开发一种新型 EPD 丝素蛋白（SF）涂层来证明，该涂层由预先组装的 SF 纳米球组装而成，用于应用模型，即通过局部递送抗生素来防止经皮骨科植入物周围的感染。这种纳米球涂层的 EPD 机制涉及到基底附近水的氧化，以中和 SF 纳米球，导致不可逆的沉积。沉积过程和质量可以通过施加的 EPD 参数轻松控制。与以传统方式组装的 EPD SF 涂层（直接从 SF 分子溶液获得）相比，这种新型涂层具有相似的粘附强度，但表现出更疏水的纳米形貌，以诱导更好的成纤维细胞反应。此外，纳米球作为构建块的使用分别使抗生素释放量和时间（最大释放量的 95%）提高了 1.38 倍和 21 倍，同时保持了药物的有效性，并表现出不可检测的细胞毒性。这种出乎意料的释放动力学归因于药物和纳米球之间的静电和疏水相互作用以及纳米球涂层的初始溶解效应可以忽略不计。这些结果表明，预组装策略在 EPD 聚合物涂层上对药物输送的卓越控制具有广阔的应用前景。
