Yoltech lipid 4, a highly efficient ionizable lipid disclosed in patent PCT/CN2023/116607, features a central tertiary amine group flanked by hydrophobic tails—specifically, a bis(2-ethylhexyl) core and a linoleyl (C18:2) chain linked via ester bonds. This structure enables pH-responsive behavior critical for mRNA/LNP delivery: neutral in circulation (reducing toxicity) but protonated in endosomes to facilitate membrane disruption and payload release. In murine studies targeting liver PCSK9, Compound 4 achieved ~90% gene-editing efficiency. Its optimized formulation yields LNPs of 70–150 nm with >90% encapsulation, ideal for hepatocyte-specific delivery.
