Liposomal membrane interface

The liposomal membrane interface is the transitional boundary region between the external aqueous environment and the hydrophobic hydrocarbon core of a liposomal lipid bilayer [1]. This interface is primarily composed of the hydrophilic head groups of phospholipids, such as phosphatidylcholine, along with sequestered water molecules and often cholesterol or surface-modifying polymers like polyethylene glycol (PEG) [2]. While it is not a biological therapeutic target in the traditional sense (e.g., a receptor or enzyme), the interface is a critical site for the partitioning and stabilization of amphiphilic drugs within liposomal delivery systems [1]. The physicochemical properties of this interface, including its zeta potential and hydration state, are engineered to control the pharmacokinetic profile, circulation time, and release kinetics of encapsulated therapeutic agents [2,3]. Interactions at the interface are also responsible for the "stealth" properties of long-circulating liposomes, which help evade the mononuclear phagocyte system to improve drug delivery to tumors or sites of infection [3]. Safety concerns associated with the liposomal interface include the potential for complement-activation-related pseudoallergy (CARPA) and the accelerated blood clearance (ABC) phenomenon upon repeated administration [2,3].

Other names

Lipid-water interfaceLiposomal bilayer interfacePhospholipid headgroup regionLiposomal surface

Facilitates drug encapsulation, stabilization, and controlled release via interfacial partitioning and modulation of membrane permeability.