TT3 together with helper lipid DMG-PEG2000 Cholesterol and mRNA formed TT3 lipid nanoparticles (LNPs) which improve the delivery efficiency of firefly luciferase FLuc mRNA over 350-fold in vitro. TT3 LNPs with human factor IX (hFIX) mRNA can efficiently improve the hFIX level to normal physiological values in FIX-knockout mice.