Liverpool John Moores University, School of Pharmacy and Biomolecular Sciences, Liverpool L3 3AF, UK.
Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Jamaica, NY, USA.
Eur J Pharm Biopharm. 2019 Mar;136:1-8. doi: 10.1016/j.ejpb.2019.01.002. Epub 2019 Jan 4.
RNA interference (RNAi) based therapeutics are considered an endogenous mechanism for modulating gene expression. In addition, microRNAs (miRNAs) may be tractable targets for the treatment of Chronic Obstructive Pulmonary Disease (COPD). In this study miR146a was adsorbed onto poly (glycerol adipate-co-ω-pentadecalactone), PGA-co-PDL, nanoparticles (NPs) to reduce target gene IRAK1 expression. NPs were prepared using an oil-in-water single emulsion solvent evaporation method incorporating cationic lipid dioleoyltrimethylammoniumpropane (DOTAP). This resulted in NPs of 244.80 ± 4.40 nm at 15% DOTAP concentration, zeta potential (ZP) of +14.8 ± 0.26 mV and miR-146a (40 µg/ml) maximum adsorption onto 15% DOTAP NPs was 36.25 ± 0.35 µg per 10 mg NP following 24 h incubation. Using the MTT assay, it was observed that over 75% at 0.312 mg/ml of A549 cells remained viable after 18 h exposure to cationic NPs at a concentration of 1.25 mg/ml. Furthermore, the in vitro release profile of miR-146a from loaded NPs showed a continuous release up to 77% after 24 h. Internalization of miR-146a loaded cationic NPs was observed in A549 cell lines using fluorescence and confocal microscopy. The miR146a delivered as miR-146a-NPs had a dose dependent effect of highest NPs concentrations 0.321 and 0.625 mg/ml and reduced target gene IRAK1 expression to 40%. In addition, IL-8 promoter reporter output (GFP) was dampened by miR-146a-NPs. In conclusion, miR-146a was successfully adsorbed onto PGA-co-PDL-DOTAP NPs and the miR-146a retained biological activity. Therefore, these results demonstrate the potential of PGA-co-PDL NPs as a delivery system for miR-146a to treat COPD.
RNA 干扰（RNAi）为基础的疗法被认为是调节基因表达的内源性机制。此外，微小 RNA（miRNA）可能是治疗慢性阻塞性肺疾病（COPD）的可行靶点。在这项研究中，miR146a 被吸附到聚（甘油癸二酸酯-co-ω-十五内酯）、PGA-co-PDL 纳米颗粒（NPs）上，以降低靶基因 IRAK1 的表达。NPs 是通过油包水单乳液溶剂蒸发法制备的，其中包含阳离子脂质二油酰基三甲基丙铵丙烷（DOTAP）。结果，在 15% DOTAP 浓度下，得到了 244.80±4.40nm 的 NPs，Zeta 电位（ZP）为+14.8±0.26mV，miR-146a（40μg/ml）在 15% DOTAP NPs 上的最大吸附量为 24h 孵育后每 10mgNP 吸附 36.25±0.35μg。通过 MTT 测定法观察到，在 1.25mg/ml 浓度下，A549 细胞暴露于阳离子 NPs 18h 后，仍有超过 75%的细胞在 0.312mg/ml 时存活。此外，负载 miR-146a 的 NPs 的体外释放曲线显示，在 24h 后释放量持续增加，达到 77%。用荧光和共聚焦显微镜观察到 miR-146a 负载的阳离子 NPs 在 A549 细胞系中的内化。miR146a 作为 miR-146a-NPs 给药具有最高 NPs 浓度 0.321 和 0.625mg/ml 的剂量依赖性效应，降低靶基因 IRAK1 表达至 40%。此外，miR-146a-NPs 抑制了 IL-8 启动子报告基因输出（GFP）。总之，miR146a 成功地吸附到 PGA-co-PDL-DOTAP NPs 上，并且 miR-146a 保留了生物活性。因此，这些结果表明 PGA-co-PDL NPs 作为 miR-146a 治疗 COPD 的递送系统具有潜力。
