O'Mahony Aoife M, Ogier Julien, Darcy Raphael, Cryan John F, O'Driscoll Caitriona M
Pharmacodelivery group, School of Pharmacy, University College Cork, Cork, Ireland.
PLoS One. 2013 Jun 21;8(6):e66413. doi: 10.1371/journal.pone.0066413. Print 2013.
Optimising non-viral vectors for neuronal siRNA delivery presents a significant challenge. Here, we investigate a co-formulation, consisting of two amphiphilic cyclodextrins (CDs), one cationic and the other PEGylated, which were blended together for siRNA delivery to a neuronal cell culture model. Co-formulated CD-siRNA complexes were characterised in terms of size, charge and morphology. Stability in salt and serum was also examined. Uptake was determined by flow cytometry and toxicity was measured by MTT assay. Knockdown of a luciferase reporter gene was used as a measure of gene silencing efficiency. Incorporation of a PEGylated CD in the formulation had significant effects on the physical and biological properties of CD.siRNA complexes. Co-formulated complexes exhibited a lower surface charge and greater stability in a high salt environment. However, the inclusion of the PEGylated CD also dramatically reduced gene silencing efficiency due to its effects on neuronal uptake. The co-formulation strategy for cationic and PEGylated CDs improved the stability of the CD.siRNA delivery systems, although knockdown efficiency was impaired. Future work will focus on the addition of targeting ligands to the co-formulated complexes to restore transfection capabilities.
优化用于神经元小干扰RNA（siRNA）递送的非病毒载体是一项重大挑战。在此，我们研究了一种共配制物，其由两种两亲性环糊精（CDs）组成，一种为阳离子型，另一种为聚乙二醇化型，将它们混合在一起用于向神经元细胞培养模型递送siRNA。对共配制的CD-siRNA复合物进行了大小、电荷和形态方面的表征。还检测了其在盐和血清中的稳定性。通过流式细胞术测定摄取情况，并通过MTT法测量毒性。使用荧光素酶报告基因的敲低作为基因沉默效率的衡量指标。在制剂中加入聚乙二醇化CD对CD-siRNA复合物的物理和生物学性质有显著影响。共配制的复合物在高盐环境中表现出较低的表面电荷和更高的稳定性。然而，由于其对神经元摄取的影响，聚乙二醇化CD的加入也显著降低了基因沉默效率。阳离子型和聚乙二醇化CD的共配制策略提高了CD-siRNA递送系统的稳定性，尽管敲低效率受到损害。未来的工作将集中于向共配制的复合物中添加靶向配体以恢复转染能力。
