TY - JOUR
T1 - Highly stable phospholipid unilamellar vesicles from spontaneous vesiculation
T2 - A DLS and SANS study
AU - Yue, Baohua
AU - Huang, Chien Yueh
AU - Nieh, Mu Ping
AU - Glinka, Charles J.
AU - Katsaras, John
PY - 2005/1/13
Y1 - 2005/1/13
N2 - Spontaneously formed unilamellar vesicles (ULV) composed of short- and long-chain phospholipids, dihexanoyl phosphorylcholine (DHPC) and dimyristoyl phosphorylcholine (DMPC), respectively, were doped with a negatively charged lipid, dimyristoyl phosphorylglycerol (DMPG), and studied with small-angle neutron scattering (SANS) and dynamic light scattering (DLS). Upon dilution, the spontaneous formation of vesicles was found to take place from bilayered micelles, or so-called "bicelles". SANS and DLS data show that ULV with narrow size distributions are highly stable at low lipid (C lp < 0.50 wt %) and NaCl salt (C s) concentrations. ULV size was found to be independent of both C lp and C s when they were below 0.33 and 0.5 wt %, respectively. Surface charge and salinity were found to be important factors in preparing ULV of a certain size. This observation is not in complete agreement with previous experimental results and cannot be completely explained with current theoretical predictions based on equilibrium calculations for catanionic surfactant mixtures. ULV size is found to be invariant over a wide range of temperatures, both below and above the phase-transition temperature, T M, of DMPC, and was stable for periods of weeks and months, even after sonication.
AB - Spontaneously formed unilamellar vesicles (ULV) composed of short- and long-chain phospholipids, dihexanoyl phosphorylcholine (DHPC) and dimyristoyl phosphorylcholine (DMPC), respectively, were doped with a negatively charged lipid, dimyristoyl phosphorylglycerol (DMPG), and studied with small-angle neutron scattering (SANS) and dynamic light scattering (DLS). Upon dilution, the spontaneous formation of vesicles was found to take place from bilayered micelles, or so-called "bicelles". SANS and DLS data show that ULV with narrow size distributions are highly stable at low lipid (C lp < 0.50 wt %) and NaCl salt (C s) concentrations. ULV size was found to be independent of both C lp and C s when they were below 0.33 and 0.5 wt %, respectively. Surface charge and salinity were found to be important factors in preparing ULV of a certain size. This observation is not in complete agreement with previous experimental results and cannot be completely explained with current theoretical predictions based on equilibrium calculations for catanionic surfactant mixtures. ULV size is found to be invariant over a wide range of temperatures, both below and above the phase-transition temperature, T M, of DMPC, and was stable for periods of weeks and months, even after sonication.
UR - http://www.scopus.com/inward/record.url?scp=12344309271&partnerID=8YFLogxK
U2 - 10.1021/jp047510q
DO - 10.1021/jp047510q
M3 - Article
C2 - 16851053
AN - SCOPUS:12344309271
SN - 1520-6106
VL - 109
SP - 609
EP - 616
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 1
ER -