However, because natural mRNA is easily broken down, this means the experimental gene therapy needs a special delivery system to make it to the body’s cells.
Moderna and Pfizer are using lipid nanoparticles that contain polyethylene glycol (PEG)2 for this purpose. The mRNA is wrapped in lipid nanoparticles (LNPs) that carry it to your cells, and the LNPs are “PEGylated” — that is, chemically attached to PEG molecules to increase stability.