Lipid nanoparticles (LNPs) are novel spherical vesicles with core-shell nanostructure. A typical LNP usually has a specially designed ionizable lipid component, which is positively charged at low pH (for RNA complexation) and neutral at physiological pH (reducing potential toxic effects compared with cationic liposomes). Due to their special characteristics and small size (~100 nm), LNPs could be uptake by cells via endocytosis and then release the cargo into the cytoplasm by low pH mediated endosomal escape. Thus, the LNPs possess additional advantages over the traditional lipid-based carriers such as improved nucleic acid encapsulation and transfection efficiency, better penetration capacity, and decreased cytotoxicity.