Lipid nanoparticle formulations of self-amplifying RNA contain lipids, phospholipids, and cholesterol (for review, see Ch. 7, Section 7.5). By which process do they enter cells?


a. beating cilia
b. phagocytosis
c. receptor-mediated endocytosis
d. macropinocytosis

Lipid nanoparticles (LNPs) are small lipid-based carriers that encapsulate nucleic acids, such as RNA, to facilitate their delivery into cells. They are composed of lipids, phospholipids, and cholesterol, which help stabilize the RNA and enhance cellular uptake. LNPs are particularly important in mRNA vaccine technology, as they protect the RNA from degradation and promote efficient delivery to target cells.

Endocytosis is a cellular process in which substances are brought into the cell by engulfing them in a membrane-bound vesicle. This process is crucial for the uptake of large molecules, such as RNA encapsulated in lipid nanoparticles. There are various forms of endocytosis, including receptor-mediated endocytosis, which is highly specific and involves the binding of ligands to cell surface receptors.

Receptor-mediated endocytosis is a selective process where cells internalize specific molecules based on their recognition by cell surface receptors. This mechanism allows for the efficient uptake of nutrients, hormones, and other signaling molecules. In the context of lipid nanoparticles, this process enables the targeted delivery of RNA to cells, enhancing the effectiveness of therapies such as vaccines.