Membrane properties of cationic liposomes composed of dipalmitoylphosphatidylcholine and dipalmityldimethylammonium bromide

Yokoyama, Shoko; Inagaki, Akiko; Imura, Tomohiro; Ohkubo, Takahiro; Tsubaki, Nobuyuki; Sakai, Hideki; Abe, Masahiko

doi:10.1016/j.colsurfb.2005.01.005

Cited by 11 publications

(11 citation statements)

References 21 publications

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“…DPAB is a cationic amphiphilic substance with dialkyl chains, and DPAB can form pure DPAB vesicles. The shape of the DPAB vesicles was that of MLVs (8). Furthermore, we confirmed using freezefracture electron microscopy that the shape of the DPPC liposomes was changed from that of MLVs to LUVs by the mixing of a small amount of DPAB into the DPPC liposomes (8).…”

Section: Introductionsupporting

confidence: 65%

“…We found using an inverted microscope with a transmitted light differential interference contrast attachment that the dipalmitoylphosphatidylglycerol liposomes (6) and the mixed dipalmitoylphosphatidylcholine (DPPC)/ceramide 3 liposomes (7) prepared by the Bangham method are MLVs, which were observed to have an onion-like structure with an inner aqueous phase. We also found using freeze-fracture electron microscopy that the shape of the DPPC liposomes (8) prepared by the Bangham method was that of MLVs. Furthermore, we found that the shape of the mixed DPPC/dipalmityldimethylammonium bromide (DPAB) liposomes (8) prepared by the Bangham method is that of LUVs.…”

Section: Introductionmentioning

confidence: 84%

“…We also found using freeze-fracture electron microscopy that the shape of the DPPC liposomes (8) prepared by the Bangham method was that of MLVs. Furthermore, we found that the shape of the mixed DPPC/dipalmityldimethylammonium bromide (DPAB) liposomes (8) prepared by the Bangham method is that of LUVs. DPAB is a cationic amphiphilic substance with dialkyl chains, and DPAB can form pure DPAB vesicles.…”

Section: Introductionmentioning

confidence: 84%

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Stearylamine Changes the Liposomal Shape from MLVs to LUVs

et al. 2005

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The shape of mixed dipalmitoylphosphatidylcholine (DPPC)/stearylamine (SA) liposomes prepared by the Bangham method was examined using freeze-fracture electron microscopy. The shape of the mixed DPPC/SA liposomes (X SA 0.05) was not that of multilamellar vesicles (MLVs) but large unilamellar vesicles (LUVs) with a diameter of approximately 1.0 mm. These facts overthrow the preconceived idea that the shape of the DPPC/SA liposomes prepared by the Bangham method is that of MLVs. The trapping efficiency of the mixed DPPC/SA liposomes (X SA 0.05) was ten times greater than that of the DPPC liposomes, since the DPPC liposomes were MLVs. The data of the DSC peak for the DPPC/SA liposomes also indicated that the shape of the DPPC/SA liposomes is that of LUVs. We emphasize that the shape of the DPPC liposomes changes from that of MLVs to LUVs by the mixing of a small amount of SA into the DPPC liposomes.

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Section: Introductionsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 84%

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Stearylamine Changes the Liposomal Shape from MLVs to LUVs

et al. 2005

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“…For DPPC, and other phosphatidylcholines, a change in sign can be experienced with increasing salt concentration, and for 150 mM NaCl both negative and positive potentials have been reported. [41][42][43] That DOPC is slightly more positive than DPPC has also been reported previously, although for different conditions. 44 The PC head group is zwitterionic in nature, and the charged subunits sit at considerable distances from each other.…”

Section: Resultssupporting

confidence: 59%

Direct measurement of surface charge distribution in phase separating supported lipid bilayers

et al. 2018

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The local surface charge density of the cell membrane influences regulation and localization of membrane proteins. The local surface charge density could, until recently, not be measured directly under physiological conditions, and it was largely a hypothetical yet very important parameter. Here we use unsaturated lipids of a distinct charge (DOTAP, DOPC, and DOPG) and a neutral fully saturated lipid (DPPC) to create model membranes with phase separating domains of a defined charge. We then apply quantitative surface charge microscopy (QSCM) to investigate the local surface charge density; this is a technique based on a scanning ion conductance microscope (SICM) capable of measuring surface charge density with nanoscale lateral resolution. We are able to clearly distinguish lipid domains from charge and topography in all three model membranes. The measured surface charge densities furthermore reveal that disordered domains formed by charged lipids are in fact not only impure, but also incorporate uncharged saturated lipids. We estimate that at least 30% of disordered domains in DOPG : DPPC and DOTAP : DPPC will be DPPC. These ratios could present a limit for the formation of charged domains in lipid membranes.

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“…Based on considerations of the economics of potential future industrial development, dialkyldimethylammonium bromides (DXDAB) and the neutral phospholipids, hydrogenated soybean phosphatidylcholine (HSPC) and egg phosphatidylcholine (EPC), are adopted herein to prepare cationic vesicles. A series of studies have noted that the general chemical structures and physical properties of dialkyldimethylammonium salts are analogous to those of phospholipids, whose components have been extensively employed in the preparation of cationic vesicles (Carmona-Ribeiro and Chaimovich, 1983;Carmona-Ribeiro, 1992;Kikuchi and Carmona-Ribeiro, 2000;Yokoyama et al, 2005;Sobral et al, 2008). The cytotoxicity of pure dioctadecyldimethylammonium bromide (DODAB) dispersions toward bacteria, fungi and some cultured mammalian cells has already been examined (Cortesi et al, 1996;Martins et al, 1997;Carmona-Ribeiro et al, 1997;Campanhã et al, 2001;CarmonaRibeiro, 2003;Korsholm et al, 2007).…”

Section: Introductionmentioning

confidence: 98%