TY - JOUR
T1 - Interaction between phospholipid vesicular structures with long chain zwitterionic surfactants
AU - Sehgal, Pankaj
AU - Doe, Hidekazu
AU - Sharma, Manu
AU - Otzen, Daniel E.
PY - 2004/5/1
Y1 - 2004/5/1
N2 - Solubilization of different zwitterionic phospholipid vesicles structures such as L-α-phosphatidyl-choline (PC) and 1,2-didecanoyl-snglycero-3-phosphocholine (DPC) have been studied in aqueous bulk by using zwitterionic surfactant dimethylhexadecylammoniopropanesulfonate (HPS). This has been done by studying the aggregation of HPS in pure water and in the presence of 7-36 μM of fixed concentrations of each lipid with the help of pyrene fluorescence intensity (I1/I3) measurements. The fluorescence measurements showed that HPS monomers undergo two kinds of aggregation process, which were identified by the three breaks in a plot of pyrene fluorescence versus HPS concentration. The first two breaks, C1 and C2, indicate the onset and completion of vesicle solubilization respectively, upon incorporation of HPS monomers into the vesicles and led to solubilization in the form of mixed micelles. This process was not clearly visible at low lipid concentration. We evaluated the partition coefficient (K), which defines the degree of partitioning of surfactant monomers into the vesicles with respect to the aqueous medium. A high K value of HPS-lipid aggregates indicates the stronger interactions between surfactant and lipid vesicles. The K values evaluated for PC and DPC are quite close to each other, which indicates that K values were independent of phospholipid chain length.
AB - Solubilization of different zwitterionic phospholipid vesicles structures such as L-α-phosphatidyl-choline (PC) and 1,2-didecanoyl-snglycero-3-phosphocholine (DPC) have been studied in aqueous bulk by using zwitterionic surfactant dimethylhexadecylammoniopropanesulfonate (HPS). This has been done by studying the aggregation of HPS in pure water and in the presence of 7-36 μM of fixed concentrations of each lipid with the help of pyrene fluorescence intensity (I1/I3) measurements. The fluorescence measurements showed that HPS monomers undergo two kinds of aggregation process, which were identified by the three breaks in a plot of pyrene fluorescence versus HPS concentration. The first two breaks, C1 and C2, indicate the onset and completion of vesicle solubilization respectively, upon incorporation of HPS monomers into the vesicles and led to solubilization in the form of mixed micelles. This process was not clearly visible at low lipid concentration. We evaluated the partition coefficient (K), which defines the degree of partitioning of surfactant monomers into the vesicles with respect to the aqueous medium. A high K value of HPS-lipid aggregates indicates the stronger interactions between surfactant and lipid vesicles. The K values evaluated for PC and DPC are quite close to each other, which indicates that K values were independent of phospholipid chain length.
KW - Bulk properties
KW - Critical micellar concentration
KW - Mixed micelles
KW - Surfactant-lipid interaction
KW - Vesicles
UR - http://www.scopus.com/inward/record.url?scp=2442516178&partnerID=8YFLogxK
U2 - 10.1007/s00396-003-0992-0
DO - 10.1007/s00396-003-0992-0
M3 - Journal article
AN - SCOPUS:2442516178
SN - 0303-402X
VL - 282
SP - 677
EP - 683
JO - Colloid and Polymer Science
JF - Colloid and Polymer Science
IS - 7
ER -