mRNA-LNP Encapsulation

LNPs are liposome-like structures, engineered for encapsulating a broad variety of nucleic acids (RNA, mRNA, siRNA, gRNA, circRNA and DNA) and APIs; LNPs consist in an aqueous core surrounded by a lipidic shell based on a combination of 4 families of chemicals: an ionizable cationic lipid, a polyethylene-glycol (PEG) lipid, cholesterol, and a helper phospholipid. The ionizable cationic lipids are used to sequester the nucleic acids through charge absorption. The PEG lipids are incorporated to increase the circulatory half-life in the body. Cholesterol is a structural "helper" lipid that improves efficacy possibly by promoting membrane fusion and promoting endosomal escape. Similarly, the helper phospholipids are also commonly used in LNP formulation to promote cell binding.