Table 1.
Typical composition and function of lipids in LNPs for mRNA delivery.
| Component | Examples | Proportion (%) | Function | Modifications and Related Functions | Refs. |
|---|---|---|---|---|---|
| Ionizable lipid | DLin-MC3-DMA, ALC-0315, SM-102 |
30–50 | Encapsulates payload mRNA, improves transfection efficacy, and enables differential delivery |
Introduction of multiple tertiary amine nitrogen atoms: higher delivery efficiency and safety | [1,8,16,17,18,19,20,21,22] |
| Phospholipid | DOPE, DSPC, DOPG | 10–20 | Helper lipids considered to improve the structural stability of formulations | A 3-phosphate group modification: improves transfection efficiency; increases the distribution in vivo | [23,24] |
| Sterol | Cholesterol, cholesterol analogues |
20–50 | Structural stability |
C-24 alkyl derivatives: regulate the integrity of the membrane; impact on delivery efficiency and biodistribution | [8,16,17] |
| PEG–lipid | PEG-DMG, PEG-DSPE |
~1.5 | Stealthiness: provides colloidal stability and enables evasion of the mononuclear phagocytic system | Covalent coupling modification: improving the half-life of LNPs | [1,18,19] |