Xu Yue, Gong Fanglin, Golubovic Alex, Strilchuk Amy, Chen Jingan, Zhou Muye, Dong Songtao, Seto Breanna, Li Bowen
Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada.
Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada.
Proc Natl Acad Sci U S A. 2025 Feb 4;122(5):e2409572122. doi: 10.1073/pnas.2409572122. Epub 2025 Jan 30.
The ionizable lipid component of lipid nanoparticle (LNP) formulations is essential for mRNA delivery by facilitating endosomal escape. Conventionally, these lipids are synthesized through complex, multistep chemical processes that are both time-consuming and require significant engineering. Furthermore, the development of new ionizable lipids is hindered by a limited understanding of the structure-activity relationships essential for effective mRNA delivery. In this work, we have developed a modular platform utilizing the Passerini reaction to rapidly generate large, chemically diverse libraries of biodegradable ionizable lipids. This high-throughput approach enables the systematic exploration of various lipid components-head groups, tails, and spacers-and their impacts on mRNA delivery efficiency. By investigating the hydrogen bonding potential between the lipid's head groups and the mRNA's ribose phosphate complex, we found that optimizing the methylene units between the lipid's head groups and linkages could enhance endosomal escape and, consequently, mRNA delivery efficiencies. Leveraging this insight, our platform has led to the identification of the biodegradable ionizable lipid A4B4-S3, which outperforms the current clinical benchmark, SM-102, in gene editing efficacy in mouse liver following systemic administration and demonstrates the promise for repeat-dose protein replacement treatments. This work not only offers a rapid, scalable method for ionizable lipid synthesis but also deepens our understanding of their structure-activity relationships, paving the way for more effective mRNA therapeutics.
脂质纳米颗粒（LNP）制剂中的可电离脂质成分通过促进内体逃逸对于mRNA递送至关重要。传统上，这些脂质是通过复杂的多步化学过程合成的，既耗时又需要大量工程技术。此外，对有效mRNA递送所必需的构效关系的有限理解阻碍了新型可电离脂质的开发。在这项工作中，我们开发了一个模块化平台，利用Passerini反应快速生成大量化学性质多样的可生物降解可电离脂质文库。这种高通量方法能够系统地探索各种脂质成分——头部基团、尾部和间隔基团——及其对mRNA递送效率的影响。通过研究脂质头部基团与mRNA的核糖磷酸复合物之间的氢键潜力，我们发现优化脂质头部基团与连接基团之间的亚甲基单元可以增强内体逃逸，从而提高mRNA递送效率。利用这一见解，我们的平台已鉴定出可生物降解的可电离脂质A4B4-S3，在全身给药后，其在小鼠肝脏中的基因编辑效果优于当前临床基准SM-102，并显示出重复剂量蛋白质替代治疗的前景。这项工作不仅为可电离脂质合成提供了一种快速、可扩展的方法，还加深了我们对其构效关系的理解，为更有效的mRNA治疗方法铺平了道路。
