Impurities in Commercial Phytantriol Significantly Alter Its Lyotropic Liquid-Crystalline Phase Behavior

Abstract

The lyotropic liquid-crystalline phase behavior of phytantriol is receiving increasing interest in the literature as a result of similarities with glyceryl monooleate, despite its very different molecular structure. Some differences in the phase-transition temperature for the bicontinuous cubic to reverse hexagonal phase have been reported in the literature. In this study, we have investigated the influence that the commercial source and hence the purity has on the lyotropic phase behavior of phytantriol. Suppression of the phase-transition temperatures (by up to 15 degrees C for the bicontinuous cubic to reverse hexagonal phase transition) is apparent with lower-purity phytantriol. In addition, the composition boundaries were also found to depend significantly on the source and purity of phytantriol, with the bicontinuous cubic phase + excess water boundary occurring at a water content above that reported previously (i.e., >5% higher). Both the temperature and compositional changes in phase boundaries have significant implications on the use of these materials and highlight the impact that subtle levels of impurities can play in the phase behavior of these types of materials.

Alkylation of Spiropyran Moiety Provides Reversible Photo-Control over Nanostructured Soft Materials

“…The lattice parameter for the H 2 phase (48-49 Å , Fig. 3b) is consistent with previous reports for the H 2 phase in phytantriol-water systems [10,26,27]. In order to exert the greatest effect on lipid packing, the photochromic molecules should align themselves in the lipid bilayer near the hydrophilic headgroups of the amphiphiles.…”

“…Briefly, the photochromics, SP, SPL and SOX were pre-dissolved in phytantriol, and phosphate buffered saline (pH 7.4) was added to the lipid phase in a ratio of 1:1 (w:w) to ensure excess water conditions [10,26,27]. The samples were heated transiently to 70°C to enable vortex mixing three times, and left to equilibrate for 1 week at 25°C before irradiation experiments.…”

Phase behavior of Phytantriol/water bicontinuous cubic Pn3m cubosomes stabilized by Laponite disc-like particles

“…Indeed, the main difference between MLO/MO and PT is the ester structure of MLO/MO, which renders hydrolysis possible depending on the pH, and leads to a chemical instability and/or disruption of the LC structure. The bulk behavior of a PT system has been presented in detail by Barauskas and Landh [16] and Dong et al [18].…”

Effects of High Pressure on Internally Self-Assembled Lipid Nanoparticles: A Synchrotron Small-Angle X-ray Scattering (SAXS) Study

“…The 'excess water boundary' (also called the maximum water solubilization line in phase diagrams) signifies that the inverse self-assembled nanostructure is not able to accommodate any further water 53,[64][65] . It is generally regarded as a 'biologically relevant' condition where physical properties, for instance, type of lipid phase, transition temperature, and lattice parameters remain constant with further addition of water 66 .…”