Small-angle X-ray (SAXS) and Raman spectroscopy studies of biot-CMG(2)-DOPE quasicrystalline phases

Abstract

Neoglycolipids due to their amphiphilic properties exhibit self-assembly in aqueous phases. In high concentrations the liquid crystalline or gel phases may form. So-called soft-material are a subject of interest of many scientists especially as biosensors and wound healing materials. In this study we examine the structure of a quasicrystalline phase of biot-CMG(2)-DOPE obtained at the concentration of 150 mg/ml (13wt.%) in PBS. The structural data such as interplanar spacing, order parameter and long-range order were obtained by SAXS, while the changes in chemical structure were studied by Raman spectroscopy. It was also in our interest to examine a correlation between the ionic strength and the self-assembly, so we also studied a similar quasicrystalline phase of the same compound but in a buffer containing CaCl2 at the concentration of 4wt.%. According to SAXS data, FSL-biotin construct formed a complex ordered phase consisting of overlapping latices of different kind. The addition of CaCl2 into PBS resulted in obtaining a more structured system demonstrating cubic-like crystal lattice. Change in peak intensities on Raman spectrums of -C-H- and -C-C- bonds vibrations explained the change in phase properties.