Hibbitts Alan, O'Connor Aoife M, McCarthy Joanna, Forde Éanna B, Hessman Gary, O'Driscoll Caitriona M, Cryan Sally-Ann, Devocelle Marc
Tissue Engineering Research Group, Department of Anatomy, Department of Chemistry, and Drug Delivery & Advanced Materials Team, School of Pharmacy, Royal College of Surgeons in Ireland (RCSI), 123 St. Stephen's Green, Dublin 2, Ireland.
Trinity Centre for Biomedical Engineering and School of Chemistry, Trinity College Dublin (TCD), The University of Dublin, College Green, Dublin 2, Ireland.
ACS Omega. 2019 Jun 10;4(6):10078-10088. doi: 10.1021/acsomega.9b00265. eCollection 2019 Jun 30.
While a wide range of experimental and commercial transfection reagents are currently available, persistent problems remain regarding their suitability for continued development. These include the transfection efficiency for difficult-to-transfect cell types and the risks of decreased cell viability that may arise from any transfection that does occur. Therefore, research is now turning toward alternative molecules that improve the toxicity profile of the gene delivery vector (GDV), while maintaining the transfection efficiency. Among them, cell-penetrating peptides, such as octa-arginine, have shown significant potential as GDVs. Their pharmacokinetic and pharmacodynamic properties can be enhanced through peptidomimetic conversion, whereby a peptide is modified into a synthetic analogue that mimics its structure and/or function, but whose backbone is not solely based on α-amino acids. Using this technology, novel peptidomimetics were developed by co- and postpolymerization functionalization of substituted ethylene oxides, producing poly(ethylene glycol) (PEG)-based peptidomimetics termed "PEGtides". Specifically, a PEGtide of the poly(α-amino acid) oligo-arginine [poly(glycidylguanidine)] was assessed for its ability to complex and deliver a small interfering ribonucleic acid (siRNA) using a range of cell assays and high-content analysis. PEGtide-siRNA demonstrated significantly increased internalization and gene inhibition over 24 h in Calu-3 pulmonary epithelial cells compared to commercial controls and octa-arginine-treated samples, with no evidence of toxicity. Furthermore, PEGtide-siRNA nanocomplexes can provide significant levels of gene inhibition in "difficult-to-transfect" mouse embryonic hypothalamic (mHypo N41) cells. Overall, the usefulness of this novel PEGtide for gene delivery was clearly demonstrated, establishing it as a promising candidate for continued translational research.
虽然目前有各种各样的实验性和商业性转染试剂，但在它们是否适合持续开发方面仍然存在一些持续性问题。这些问题包括对难以转染的细胞类型的转染效率，以及任何已发生的转染可能导致的细胞活力下降风险。因此，现在的研究正转向替代分子，这些分子在保持转染效率的同时，能改善基因递送载体（GDV）的毒性特征。其中，细胞穿透肽，如八聚精氨酸，已显示出作为基因递送载体的巨大潜力。它们的药代动力学和药效学特性可以通过拟肽转化得到增强，即把一种肽修饰成模拟其结构和/或功能的合成类似物，但其主链并非仅基于α-氨基酸。利用这项技术，通过取代环氧乙烷的共聚和后聚合功能化开发了新型拟肽，产生了基于聚乙二醇（PEG）的拟肽，称为“PEGtides”。具体而言，使用一系列细胞试验和高内涵分析评估了聚（α-氨基酸）寡聚精氨酸[聚（缩水甘油胍）]的一种PEGtide复合和递送小干扰核糖核酸（siRNA）的能力。与商业对照和八聚精氨酸处理的样品相比，PEGtide-siRNA在Calu-3肺上皮细胞中24小时内的内化和基因抑制作用显著增强，且没有毒性迹象。此外，PEGtide-siRNA纳米复合物能在“难以转染”的小鼠胚胎下丘脑（mHypo N41）细胞中提供显著水平的基因抑制。总体而言，这种新型PEGtide在基因递送方面的实用性得到了明确证明，使其成为持续转化研究的一个有前景的候选者。
