Endosomal lipid bilayer

The endosomal lipid bilayer is a dynamic, semi-permeable membrane that defines the boundaries of endosomes, playing a critical role in the sorting and trafficking of internalized extracellular material and surface receptors. It is composed of a complex mixture of phospholipids, cholesterol, and phosphoinositides that evolve in composition as the endosome matures from early to late stages (Nature Nanotechnology, 2021). This structure serves as a primary barrier for the intracellular delivery of macromolecular therapeutics, such as mRNA and siRNA, which must escape the endosome to reach the cytosol to be functional (Journal of Controlled Release, 2014). In many viral infections, including those caused by influenza and coronaviruses, the endosomal lipid bilayer is the site where viral envelopes fuse with host membranes, a process often triggered by the acidic environment of the endosomal lumen (Cell, 2014). Drugs targeting this structure typically aim to either facilitate endosomal escape for gene therapy or inhibit viral fusion to prevent infection (PubMed, 16115318). Additionally, alterations in the lipid composition or integrity of this bilayer are implicated in lysosomal storage disorders and neurodegenerative diseases like Alzheimer's (NIH, 2020). Understanding the biophysical properties of the endosomal lipid bilayer is essential for optimizing drug delivery systems and developing novel antiviral strategies.

Other names

Endosomal membraneEndosome membraneEndocytic membraneEndosomal vesicle membrane

Facilitation of endosomal escape via pH-triggered membrane destabilization or fusion; inhibition of viral-endosomal membrane fusion; modulation of endosomal pH to disrupt trafficking.