Lipid Nanoparticles and the Revolution in mRNA Medicine

A lipid nanoparticle in a cell, from Cross, R

We know that the end of the Covid-19 pandemic is due to the development and spread of the messenger RNA (mRNA) vaccines, but not many people know exactly how they work. In truth, mRNA is quite finicky and hard to bend to your goals. The enzymes (proteins that speed up chemical reactions) in our bodies and environment quickly chop up mRNA, rendering them useless. In addition to that, mRNA can’t easily go through our cell membranes, making it very hard for it to fight the Covid-19 viruses. Fortunately, scientists found a marvelous solution to fix this essential problem: lipid nanoparticles.

What are lipid nanoparticles?

Lipid nanoparticles are, in short, very small fat bubbles in your body that can be used to transport vaccines and other things into your cells. They are made of four things: ionizable lipids, phospholipids, PEG-lipids, and cholesterol. Ionizable lipids are selectively charged lipids that can withstand a wide range of pHs, helping the nanoparticle survive in a wide range of environments. Phospholipids are very important in lipid nanoparticle formation, making sure that the nanoparticle has a stable structure and effectively spreading the particles so they can deliver drugs to cells on a wider scale. Cholesterol has many different functions in lipid nanoparticles, such as keeping the particle as rigid as it needs to be and keep it from falling apart. PEG-lipids make sure that the immune system doesn’t think the particle’s an enemy and prevent unwanted protein build-up. 

Lipid nanoparticles are always artificially made, through a number of procedures like pipette mixing (when you mix the components by repeated injections) and ethanol injections (when the components are dissolved in ethanol and mixed around until the nanoparticles form). 

What are they even used for?

The biggest and most recent purpose lipid nanoparticles have been used for is the Covid-19 vaccine, saving millions of lives.They’re also very important in the vaccines for influenza since mRNA lipid nanoparticles can help make universal ones, important in the rapid evolution of the virus. The particles have even shown promise in fighting cancer! In hematological malignancies (blood cancers), the virus vectors currently used in some treatments have severe long-term effects. As a response to this, lipid nanoparticles could be used to deliver the mRNA the vectors make, reducing the risk. Also, engineered mRNA could possibly be used to destroy solid tumors without hurting regular cells (though this is still under study). In addition to fighting various diseases, lipid nanoparticles have shown promise in improving the general efficiency and quality of cells, improving the resources the cell takes in to use, and tracking medicine in the body to make sure it works. 

Lipid nanoparticles as a major way of drug delivery are still being studied, and the real uses of it are mostly in the Covid-19 vaccine. Still, it has enormous potential and its usage in a vaccine to a pandemic-causing virus shows its prowess already. Whatever the future holds for them, they are immensely intriguing and contribute to our growing progress in medicine.

References

Cross, R. (2021, March 6). Without these lipid shells, there would be no mRNA vaccines for COVID-19. Acs.Org. https://cen.acs.org/pharmaceuticals/drug-delivery/Without-lipid-shells-mRNA-vaccines/99/i8

Xu, S., Hu, Z., Song, F., Xu, Y., & Han, X. (2025). Lipid nanoparticles: Composition, formulation, and application. Molecular Therapy Methods & Clinical Development, 33(2), 101463. https://doi.org/10.1016/j.omtm.2025.101463

Lipid Nanoparticles – Johns Hopkins Translational ImmunoEngineering. (2025). Jhmi.Edu. https://jhtie.jhmi.edu/lipidnanoparticles/