Preparation of Liposomes from Soy Lecithin Using Liquefied Dimethyl Ether

Abstract

We investigated a method to prepare liposomes; soy lecithin was dissolved in liquefied dimethyl ether (DME) at 0.56 MPa, which was then injected into warm water. Liposomes can be successfully prepared at warm water temperatures above 45 °C. The transmission electron microscopy (TEM) images of the obtained liposomes, size distribution, ζ-potential measurements by dynamic light scattering and the amount of residual medium were compared by gas chromatography using the conventional medium, diethyl ether. The size of the obtained liposomes was approximately 60–300 nm and the ζ-potential was approximately −57 mV, which was almost the same as that of the conventional medium. Additionally, for the conventional media, a large amount remained in the liposome dispersion even after removal by depressurization and dialysis membrane treatment; however, liquefied DME, owing to its considerably low boiling point, was completely removed by depressurization. Liquefied DME is a very attractive medium for the preparation of liposomes because it does not have the toxicity and residue problems of conventional solvents or the hazards of ethanol addition and high pressure of supercritical carbon dioxide; it is also environmentally friendly.

Acoustically-Activated Liposomal Nanocarriers to Mitigate the Side Effects of Conventional Chemotherapy with a Focus on Emulsion-Liposomes

“…[ 43 , 44 ]. Phospholipids are the main structural components of liposomes, where the most commonly used are soy phosphatidylcholine (soy PC) [ 39 ], egg phosphatidylcholine (egg PC) [ 40 ], phosphatidylcholine (PC), and milk fat phospholipids [ 41 ]. Phospholipids occur abundantly in nature; however, their synthetic derivatives also exist, such as 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) as derivatives of PC, and 1,2-Dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) as a derivative of PE, etc.…”

Lipid-Based Nanotechnology: Liposome

“…Typically, solvent injection will produce LUVs. Alternatively, if the organic solvent has a higher boiling point than the aqueous phase, then after injection, the organic solvent can be removed by dialysis, centrifugation, or passing through a Sepharose gel column [ 48 , 49 ].…”

Liposomes: preparation and characterization with a special focus on the application of capillary electrophoresis

“…Another method of liposome preparation is the ethanol injection method, which is based on rapid injection of the lipid suspension into the aqueous phase. The advantages of this method include the simplicity of the operation and the possibility of preparing a large quantity of liposomes [ 20 , 23 , 24 ]. An alternative to the ethanol injection method is the ether injection method, where lipids are dissolved in diethyl ether and injected into the aqueous phase.…”

“…An alternative to the ethanol injection method is the ether injection method, where lipids are dissolved in diethyl ether and injected into the aqueous phase. Thanks to the higher solubility of lipids in ether, liposomes of higher lipid concentrations can be made using this method [ 2 , 20 , 23 ].…”