Effect of Glucose and Methyl Glucoside on the Structure and Physicochemical Properties of Liposomes

Sugars have been widely used as humectants and cryoprotectants in the cosmetics and pharmaceutical industries; thus, investigating their effects on the structure and properties of lipid bilayers can provide valuable insights for the development of functional lipid nanoparticles and drug delivery systems. In this study, glucose (Glc) and methyl glucoside (m-Glc) were introduced to phospholipid-derived liposomes. The particle size of the resulting liposomes, as determined by dynamic light scattering, decreased in the low-concentration range (5-10 wt%) in the Glc-containing system and at a higher concentration (30 wt%) in the m-Glc-containing system, and both systems showed improved dispersion stability. The bilayer structures of liposomes were analyzed by small-angle X-ray scattering (SAXS) measurements followed by generalized indirect Fourier transformation (GIFT) analysis. Unlike polyhydric alcohol-containing systems reported in our previous studies, the thickness of the bilayer (D max ) of sugar-containing liposomes remained nearly constant regardless of the type or concentration of the sugar. This is likely because the hydrophilic groups of the sugar molecules formed hydrogen bonds preferentially with the hydrophilic regions on the surface of the bilayer. Therefore, the interactions with the interior of the bilayer were limited, preventing the formation of an interdigitated structure observed for polyhydric alcohols. In addition, Caillé parameter (η), which serves as an indicator of membrane flexibility, increased in both the Glc- and m-Glc-containing systems compared with the water system, and the enhanced membrane flexibility contributed to improved dispersion stability. Differential scanning calorimetry (DSC) measurements revealed a higher gel/liquid crystal phase transition temperature (T c ) upon the addition of sugars, implying that the packing between hydrophobic groups was maintained. Furthermore, the addition of sugars resulted in a sharper pre-transition peak, suggesting the formation of a ripple phase or microphase separation of a bilayer.

Abstract from PubMed (PMID 42968319). This entry was added automatically by our daily literature monitor because it matches the topics we follow; read the full paper at the original source.