Crystallography of dispersed liquid crystalline phases studied by cryo-transmission electron microscopy
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Crystallography of dispersed liquid crystalline phases studied by cryo-transmission electron microscopy. / Sagalowicz, L.; Michel, M.; Adrian, M.; Frossard, P.; Rouvet, M.; Watzke, H. J.; Yaghmur, A.; De Campo, L.; Glatter, O.; Leser, M. E.
In: Journal of Microscopy, Vol. 221, No. 2, 01.02.2006, p. 110-121.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Crystallography of dispersed liquid crystalline phases studied by cryo-transmission electron microscopy
AU - Sagalowicz, L.
AU - Michel, M.
AU - Adrian, M.
AU - Frossard, P.
AU - Rouvet, M.
AU - Watzke, H. J.
AU - Yaghmur, A.
AU - De Campo, L.
AU - Glatter, O.
AU - Leser, M. E.
PY - 2006/2/1
Y1 - 2006/2/1
N2 - Low molecular weight surfactants, for example monoglycerides and phospholipids, form a multitude of self-assembled structures, such as inverted cubic or hexagonal mesophases, if brought into contact with water/oil. These mesophases can be dispersed in water using adequate surface-active materials such as low molecular weight surfactants or surface active polymers. In order to use such mesophase particles for incorporating drugs and aromas, it is essential to determine their internal crystallographic structure and to understand their mechanism of stabilization. Cryo-transmission electron microscopy was used to investigate the internal structure of different dispersed particles at various temperatures and oil contents. It is shown here that cryo-transmission electron microscopy, in combination with fast Fourier transform and tilting experiments, is effective in obtaining information on crystallographic structure, space group and morphology of particles with reversed bicontinuous cubic and hexagonal structures. In particular, using the presence or the absence of the {111} reflections and viewing the same particle under different axes of observation allows one to discriminate between the Im3m and Pn3m space groups. A major advantage of cryo-transmission electron microscopy is the ability to analyse single particles. This allows the identification of particles present at very low concentrations and the coexistence of particles with different internal self-assembly structures. With this technique we have obtained strong evidence for the presence of two cubic internal self-assembly structures with different space groups within the same dispersion. In addition, we found that cryo-transmission electron microscopy combined with tilting experiments enables the analysis of internal particle morphology, allowing the discussion of mechanisms for hexosome stabilization.
AB - Low molecular weight surfactants, for example monoglycerides and phospholipids, form a multitude of self-assembled structures, such as inverted cubic or hexagonal mesophases, if brought into contact with water/oil. These mesophases can be dispersed in water using adequate surface-active materials such as low molecular weight surfactants or surface active polymers. In order to use such mesophase particles for incorporating drugs and aromas, it is essential to determine their internal crystallographic structure and to understand their mechanism of stabilization. Cryo-transmission electron microscopy was used to investigate the internal structure of different dispersed particles at various temperatures and oil contents. It is shown here that cryo-transmission electron microscopy, in combination with fast Fourier transform and tilting experiments, is effective in obtaining information on crystallographic structure, space group and morphology of particles with reversed bicontinuous cubic and hexagonal structures. In particular, using the presence or the absence of the {111} reflections and viewing the same particle under different axes of observation allows one to discriminate between the Im3m and Pn3m space groups. A major advantage of cryo-transmission electron microscopy is the ability to analyse single particles. This allows the identification of particles present at very low concentrations and the coexistence of particles with different internal self-assembly structures. With this technique we have obtained strong evidence for the presence of two cubic internal self-assembly structures with different space groups within the same dispersion. In addition, we found that cryo-transmission electron microscopy combined with tilting experiments enables the analysis of internal particle morphology, allowing the discussion of mechanisms for hexosome stabilization.
KW - Cryo-TEM
KW - Cubosomes
KW - Dispersion
KW - Freeze fracture
KW - Hexosomes
KW - Liquid crystals
KW - Mesophases
KW - Monoglyceride
KW - SAXS
KW - Vesicles
UR - http://www.scopus.com/inward/record.url?scp=33644755736&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2818.2006.01544.x
DO - 10.1111/j.1365-2818.2006.01544.x
M3 - Journal article
AN - SCOPUS:33644755736
VL - 221
SP - 110
EP - 121
JO - Journal of Microscopy
JF - Journal of Microscopy
SN - 0022-2720
IS - 2
ER -
ID: 221830428