lipid nanoparticles

"Spherical vesicles made of ionizable lipids, which are positively charged at low pH (enabling RNA complexation) and neutral at physiological pH (reducing potential toxic effects, as compared with positively charged lipids, such as liposomes)."  

 

Source: https://www.nature.com/articles/s41578-021-00281-4#:~:text=Lipid%20nanoparticles%20are%20spherical%20vesicles,lipids%2C%20such%20as%20liposomes).

 

"When the mRNA COVID-19 vaccine is injected into the arm, these LNP delivery vehicles shuttle the mRNA instructions into cells. The instructions are then unloaded, and the cell can make the spike protein ..."  Source:  https://www.pfizer.com/news/behind-the-science/inside-delivery-vehicles-critical-success