Phospholipids can significantly enhance the interaction between LNPs and endosomal membranes

The research team used Förster resonance energy transfer (FRET) to assess how phospholipid content affects the interaction between LNPs and endosomal membranes. The results showed that adding phospholipids, in a formulation-dependent manner, markedly increased fusion with endosomal membranes.

Phospholipids can improve the in vitro cellular transfection efficiency of LNPs

The research team transfected HEK293 and HeLa cells with luciferase mRNA using LNPs containing varying amounts of phospholipids. By measuring average luminescence intensity to determine luciferase activity, they quantitatively assessed intracellular endosomal escape and mRNA transfection expression. The findings revealed that LNPs with 0% phospholipid content exhibited lower transfection efficiency, whereas transfection efficiency significantly improved as phospholipid content increased.

Figure 3: Comparison of transfection efficiency of HeLa cells by LNPs with different phospholipid contents [1]

Phospholipids can enhance SORT LNP-mediated mRNA delivery efficiency in vivo

The research team injected gradient-phospholipid-content LNPs carrying human erythropoietin mRNA into C57BL/6 mice aged 6–8 weeks, evaluating transfection efficiency through quantitative measurement of protein secretion produced by transfected cells. Results indicated that increasing phospholipid content in LNPs led to enhanced transfection efficiency. Notably, the optimal phospholipid addition ratio was formulation-dependent.

Figure 4: In vivo mRNA transfection expression comparison among LNPs with different phospholipid contents [1]

Phospholipid content influences LNP morphology

The research team employed cryo-electron microscopy to directly reveal how phospholipids reshape the nanostructure of LNPs.

Figure 5: Cryo-EM images of LNPs with different phospholipid contents [1]

In liver-targeting SORT LNPs, phospholipid enrichment induced the formation of a semi-ordered lipid core; this outwardly protruding structure may indicate higher fusion activity of the LNP.

In lung-targeting SORT LNPs, increased phospholipid content resulted in a transition from disordered monolayer to multilayer vesicular structures, potentially affecting the exposure of SORT lipids on the particle surface.

In spleen-targeting SORT LNPs, particles with 0% phospholipid content had sharp, irregular edges, while the addition of phospholipids made their morphology more regular and spherical, enhancing membrane stability.

Summary

This study has reshaped industry understanding of the role of phospholipids in advanced LNP delivery systems. Phospholipids are not merely “auxiliary lipids” maintaining structural stability; they also serve as multifunctional “molecular helmsmen,” regulating LNP membrane fusion kinetics, endosomal escape efficiency, cellular uptake, nanostructural morphology, and ultimately organ-specific targeting. This research suggests that when designing next-generation LNPs, phospholipids should be regarded as a key functional design parameter rather than a passive structural component. With deeper insights into inter-lipid interactions, organ-specific LNP therapies tailored to individual needs will accelerate from vision toward reality.

References:

[1] Guerrero, Erick D et al. “Investigating the functional contributions of phospholipids in selective organ targeting lipid nanoparticles.” Biomaterials vol. 326 (2026): 123671.

Further Reading

Guangzhou Baiyunshan Hanfang Modern Pharmaceutical is committed to providing end-to-end support—from mature excipients to innovative candidate materials—for the global development of fat emulsions, LNP, and liposome drug formulations, helping drive technological breakthroughs and industrial growth in the biopharmaceutical field!

Table 1: Partial List of the Company’s Injectable Lipid Products