Lipid bilayer of cellular membranes

The lipid bilayer of cellular membranes is a fundamental biological structure composed of two layers of amphiphilic phospholipids, providing a semi-permeable barrier that separates the interior of cells and organelles from the external environment (Wikipedia: Lipid bilayer). It serves as a matrix for membrane proteins and plays a critical role in signal transduction, transport, and maintaining electrochemical gradients. In pharmacology, the lipid bilayer is a direct target for several classes of anti-infective agents, such as polyene antifungals and lipopeptide antibiotics, which exploit differences in lipid composition (e.g., ergosterol vs. cholesterol) between host and pathogen membranes (StatPearls: Antifungal Medications). Beyond direct disruption, the physical state of the bilayer influences the activity of embedded receptors and channels, making it a key factor in the pharmacodynamics of general and local anesthetics. Therapeutic strategies targeting the membrane often focus on inducing pore formation or altering membrane permeability to trigger cell death in pathogens or malignant cells (Nature Reviews Drug Discovery: The membrane as a drug target).

Other names

Plasma membraneCell membranePhospholipid bilayerCytoplasmic membraneBiological membrane

Drugs targeting the lipid bilayer typically act by disrupting its structural integrity or physical properties. This includes the formation of transmembrane pores (e.g., polyenes) that lead to ion leakage and cell death, the sequestration of essential lipids like ergosterol or lipid II, and the alteration of membrane fluidity or curvature. Some agents, such as polymyxins, exert a detergent-like effect by displacing divalent cations from phosphate groups, solubilizing the membrane components to cause rapid lysis (PubMed: 25231515; StatPearls: Amphotericin B).