The University of Texas Southwestern Medical Center, Department of Biochemistry, Simmons Comprehensive Cancer Center, Dallas, TX, USA.
Nat Mater. 2021 May;20(5):701-710. doi: 10.1038/s41563-020-00886-0. Epub 2021 Feb 4.
Endosomal escape remains a fundamental barrier hindering the advancement of nucleic acid therapeutics. Taking inspiration from natural phospholipids that comprise biological membranes, we report the combinatorial synthesis of multi-tailed ionizable phospholipids (iPhos) capable of delivering messenger RNA or mRNA/single-guide RNA for gene editing in vivo. Optimized iPhos lipids are composed of one pH-switchable zwitterion and three hydrophobic tails, which adopt a cone shape in endosomal acidic environments to facilitate membrane hexagonal transformation and subsequent cargo release from endosomes. Structure-activity relationships reveal that iPhos chemical structure can control in vivo efficacy and organ selectivity. iPhos lipids synergistically function with various helper lipids to formulate multi-component lipid nanoparticles (called iPLNPs) for selective organ targeting. Zwitterionic, ionizable cationic and permanently cationic helper lipids enable tissue-selective mRNA delivery and CRISPR-Cas9 gene editing in spleen, liver and lungs (respectively) following intravenous administration. This rational design of functional phospholipids demonstrates substantial value for gene editing research and therapeutic applications.
内涵体逃逸仍然是阻碍核酸治疗发展的一个基本障碍。受构成生物膜的天然磷脂的启发，我们报告了多尾可离子化磷脂（iPhos）的组合合成，该磷脂能够在体内递送信使 RNA 或 mRNA/单指导 RNA 进行基因编辑。优化的 iPhos 脂质由一个 pH 可切换的两性离子和三个疏水性尾巴组成，在内涵体酸性环境中采用锥形结构，有利于膜六方相转变和随后的内涵体中货物的释放。结构-活性关系表明，iPhos 的化学结构可以控制体内疗效和器官选择性。iPhos 脂质与各种辅助脂质协同作用，用于配制多组分脂质纳米颗粒（称为 iPLNPs），以实现选择性器官靶向。两性离子、可离子化阳离子和永久性阳离子辅助脂质可使静脉注射后脾脏、肝脏和肺部（分别）中组织选择性的 mRNA 递送达和 CRISPR-Cas9 基因编辑成为可能。这种功能性磷脂的合理设计为基因编辑研究和治疗应用提供了巨大的价值。
