Liposome anionic

Awasthi VD, Garcia D, Klipper R, et al. Neutral and anionic liposome-encapsulated hemoglobin effect of postinserted poly(ethylene glycol)-distearoylphospha-tidylethanolamine on distribution and circulation kinetics. J Pharmacol Exp Ther 2004 309 241. 

The amino acid sequences of haptides comprise hydrophobic and cationic residues with a net charge of +4 to +5 per 19 to 21 amino acids. It was proposed that haptides could be attracted to the anionic liposomes as well as the anionic cell membrane and that the hydrophobic properties of the haptide facilitate membrane translocation (106). Haptide uptake was reported to be energy independent, occurring at 4°C. The advantage of this peptide compared to CPP such as TAT and Antp, is that, unlike the virus-derived peptides, the haptides are not recognized as foreign antigens and do not induce cell transformation (106). However, haptides have also been found to accelerate fibrin clot formation and lack cell specificity (106). 

Lakkaraju A, Rahman YE, Dubinsky JM. Low-density lipoprotein receptor-related protein mediates the endocytosis of anionic liposomes in neurons. J Biol Chem 2002 277(17) 15085-15092. 

Fig. 25 (a) DNA release from EDOPC-DNA lipoplexes after addition of negatively charged lipid dispersion, as monitored by FRET (CM, oleic acid DOPA, dioleoyl phosphatidic acid DOPG, dioleoyl phosphatidylglycerol CL, cardiolipin DOPS, dioleoyl phosphatidylserine PI, phospha-tidylinositol). (b) Fraction of released DNA from EDOPC lipoplexes 10 min after addition of the respective anionic liposomes (c) X-ray diffraction patterns of mixtures of EDOPC and anionic liposome dispersions the respective structures are shown schematically on the left side (reproduced with permission from [98] copyright (2004) Biophysical Society)... 

With the optimized lipid composition (opDC ePC DOPE eSph Choi DC-Chol = 5 5 5 12 3), the HVJ-cationic liposomes showed 100 to 800 times greater transfection efficiency in vitro compared with the conventional HVJ-PS liposomes. The presence of serum (10% FCS) in the transfection mixture did not decrease luciferase activity significantly. Even 70% FCS reduced the activity by less than 40%. LacZ gene expression showed that transfection efficiency of BHK-21 cells by optimized HVJ-cationic liposomes (opDC) and by conventional HVJ-cationic liposomes (DC) was 90-100% and 50-60%, respectively. With conventional HVJ-anionic liposomes (PS), LacZ expression was found in only 1-3% of the cells. The optimized HVJ-cationic liposomes were also much more effective for the transfer of FITC-labeled ODNs to cultured cells [16]. 

Mozafari MR, Reed CJ, Rostron C, Kocum C, Piskin E (2002) Construction of stable anionic liposome-plasmid particles using the heating method a preliminary investigation. Cell Mol Biol Lett 7 923-927... 

Anionic liposome was prepared by the film method on a rotary evaporator Heidolph, VWR, equipped with a vacuubrand CVC2 to control the pressure. Sonication was performed on sonicator branson 1210. Size and zeta potentials measurements were performed on a Zeta Sizer NanoSeries from Malvern Instruments equipped with a MPT2 autotitrator. Fluorescence was measured on a multilabel plate reader Wallac Victor2 1420 Multilabel Counter, Perkin Elmer, France, equipped with excitation and emission filters (350 10 nm, 450 10 nm). 

Leave the sample 1 h at room temperature to incubate before using it or adding it to the anionic liposomes. 

The anionic liposomes were prepared by the film method as described for the cationic liposome in Subheading 3.1. 

The preformed cationic lipopiexes were added to the anionic liposomes according to the charge lipid ratio DMAPAP/CCTC... 

Prepare a suspension of the anionic liposomes at 0.55 mM from the 20.5 mM suspension prepared in Subheading 3.3. 

Dilute lOOpL of this anionic liposome suspension in Hepes 20 mM, glucose 10%... 

Add the preformed lipopiexes described in Subheading 3.2 to the suspension of the anionic liposomes. 

Folate-targeted LPD-II particles were generated by mixing anionic liposomes composed of DOPE/cholesteryl hemisuccinate (CHEMS)/ folate-polyethyleneglycol (PEG)-DOPE and the cationic DNA-polylysine (1 0.75, w/w) complexes. Structural analysis of LPD-II by negative-stain EM showed that the DNA-polylysine (which appears individually as rod shaped) and lipid complex seemed to be a highly electron dense, spherical core with a low-density coating. The mean diameter of these particles was 74 14 nm, i.e., smaller than the empty liposomes. 

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