Negatively charged phospholipid membrane

Negatively charged phospholipid membranes are biological surfaces characterized by a high concentration of anionic lipids, including phosphatidylserine (PS), phosphatidylglycerol, and cardiolipin. In healthy mammalian cells, these lipids are typically restricted to the inner leaflet of the plasma membrane, but they become exposed on the outer surface during apoptosis, platelet activation, or malignant transformation (Birge et al., 2016, PMID: 27153392). This loss of membrane asymmetry creates a distinct biochemical signature that differentiates pathological cells or bacterial pathogens from healthy host cells. Consequently, these membranes serve as a selective target for various therapeutic classes, including cationic antimicrobial peptides and lipopeptides that exploit the negative charge of bacterial surfaces (Velkov et al., 2013, PMID: 24079232). In oncology, the exposure of PS on tumor cells and tumor-associated vascular endothelium provides a docking site for targeted antibodies and imaging agents designed to disrupt tumor growth and stimulate immune responses. Furthermore, the interaction of drugs with these membranes can lead to rapid membrane depolarization or the induction of antibody-dependent cellular cytotoxicity (ADCC). Understanding the dynamics of anionic lipid exposure is crucial for developing therapies that minimize off-target effects on healthy tissues while maximizing potency against pathogens and tumors (He et al., 2019, PMID: 31110262).

Other names

Anionic phospholipid membraneAcidic phospholipid membranePhosphatidylserine-exposed membraneAnionic lipid bilayer

Drugs targeting negatively charged phospholipid membranes primarily utilize electrostatic interactions between cationic drug moieties and anionic lipid headgroups, such as phosphatidylserine or phosphatidylglycerol (Velkov et al., 2013, PMID: 24079232). This binding often leads to membrane permeabilization, pore formation, and loss of cytoplasmic contents, as seen with antimicrobial peptides and lipopeptides like daptomycin (Muller et al., 2016, PMID: 27341313). In the context of cancer, therapeutic antibodies like bavituximab bind to exposed anionic phospholipids to facilitate immune-mediated destruction of tumor cells and vasculature (Birge et al., 2016, PMID: 27153392). Additionally, some agents inhibit essential membrane-associated processes, such as cell wall synthesis, by sequestering lipid intermediates like Lipid II on the anionic surface.