Department of Pharmacy, Biopharmaceutics and Pharmaceutical Technology, Saarland University, Campus C4 1, 66123 Saarbrücken, Germany.
Anatomy and Cell Biology, Medical Faculty, Saarland University, building 61, 66421 Homburg, Germany.
Eur J Pharm Biopharm. 2021 Jan;158:284-293. doi: 10.1016/j.ejpb.2020.11.024. Epub 2020 Dec 5.
The delivery of oligonucleotides such as siRNA to the lung is a major challenge, as this group of drugs has difficulties to overcome biological barriers due to its polyanionic character and the associated hydrophilic properties, resulting in inefficient delivery. Especially in diseases such as asthma, chronic obstructive pulmonary disease and cystic fibrosis, where increased proinflammation is present, a targeted RNA therapy is desirable due to the high potency of these oligonucleotides. To address these problems and to ensure efficient uptake of siRNA in macrophages, a microparticulate, cylindrical delivery system was developed. In the first step, this particle system was tested for its aerodynamic characteristics to evaluate the aerodynamic properties to optimize lung deposition. The mass median aerodynamic diameter of 2.52 ± 0.23 µm, indicates that the desired target should be reached. The inhibition of TNF-α release, as one of the main mediators of proinflammatory reactions, was investigated. We could show that our carrier system can be loaded with siRNA against TNF-α. Gel electrophoreses allowed to demonstrate that the load can be incorporated and released without being degraded. The delivery system was found to transport a mass fraction of 0.371% [%w/w] as determined by inductively coupled plasma mass spectroscopy. When investigating the release kinetics, the results showed that several days are necessary to release a major amount of the siRNA indicating a sustained release. The cylindrical microparticles with an aspect ratio of 3.3 (ratio of length divided by width) were then tested in vitro successfully reducing TNF-α release from human macrophages significantly by more than 30%. The developed formulation presents a possible oligonucleotide delivery system allowing due to its internal structure to load and protect siRNA.
将寡核苷酸（如 siRNA）递送到肺部是一个主要挑战，因为由于其多阴离子特性和相关的亲水性，这组药物难以克服生物屏障，导致递送效率低下。特别是在哮喘、慢性阻塞性肺疾病和囊性纤维化等疾病中，由于存在过度炎症，需要靶向 RNA 治疗，因为这些寡核苷酸具有很高的效力。为了解决这些问题并确保 siRNA 在巨噬细胞中有效摄取，开发了一种微粒、圆柱形递药系统。在第一步中，对该粒子系统进行了空气动力学特性测试，以评估其优化肺部沉积的空气动力学特性。2.52±0.23µm 的质量中值空气动力学直径表明应该达到所需的目标。研究了作为促炎反应主要介质之一的 TNF-α 释放的抑制作用。我们可以证明我们的载体系统可以负载针对 TNF-α 的 siRNA。凝胶电泳允许证明可以在不降解的情况下掺入和释放负载。递药系统被发现可以输送 0.371%（[w/w]）的质量分数，这是通过电感耦合等离子体质谱法确定的。在研究释放动力学时，结果表明需要几天时间才能释放大部分 siRNA，表明持续释放。然后成功地在体外测试了具有 3.3（长度与宽度之比）纵横比的圆柱形微粒，显著降低了人巨噬细胞中 TNF-α 的释放超过 30%。开发的制剂提供了一种可能的寡核苷酸递药系统，由于其内部结构，能够负载和保护 siRNA。
