Preparation of Small Unilamellar Vesicle Liposomes Using Detergent Dialysis Method

Small unilamellar liposomes are commonly used as model biomembranes and carriers for drug and gene delivery. Although methods which employ mechanical forces or organic solvents can be used to reduce the liposome size and the number of lipid bilayers, they are not suitable options when the purpose is to incorporate biologically active proteins into lipid bilayers or to encapsulate nucleic acid into liposomes. Detergent dialysis is a simple and inexpensive procedure to produce homogeneous small unilamellar vesicles (SUVs). Lipids are solubilized by detergent at a concentration much higher than its critical micellar concentration (CMC) in an aqueous dispersion medium. Free monomer detergent molecules in the dispersion medium are removed during dialysis, while the supramolecular detergent-lipid mixed micelles (MMs) are kept inside the dialysis tubing, leading to dissociation of detergent molecules from MMs. SUVs are formed after the micelle to vesicle transition (MVT).