Effect of phospholipid/flaxseed oil ratio on characteristics, structure change, and storage stability of liposomes

The flaxseed oil, a rich source of α-linolenic acid, was loaded in liposomes. The vesicle characteristics, encapsulation efficiency, and loading content with different amounts of flaxseed oil addition were investigated. At the ratio of phospholipid to flaxseed oil 5:1, the liposomes displayed an almost spherical shape and a homogeneous size distribution (observed by transmission electron microscopy and atomic force microscopy), with an average particle size 156 nm and an encapsulation efficiency of approximately 85%. The addition of flaxseed oil could change the phospholipid arrangement by Fourier-transform infrared spectroscopy and Raman spectra. The hydrophobicity of membrane surface and the micropolarity of the bilayer interior decreased with the incorporation of flaxseed oil by fluorescence probe analysis. Liposomes showed higher oxidative stability and retention rate during the storage at the ratio of 5:1. In addition, the encapsulation of flaxseed oil in liposomes showed the ability of slower release. It comprehensively illustrated the flaxseed oil could affect the membrane structure of liposomes and provided useful information regarding the preparation of liposomes for hydrophobic compounds.