Spontaneous formation of vesicles from complexes of block ionomers and surfactants [1]

Journal of the American Chemical Society

Volumn 120, Issue 38, 1998, Pages 9941-9942

  Kabanov, A V ^a   Bronich, T K ^a   Kabanov, V A ^a   Yu, K ^a   Eisenberg, A ^a  

^a UNIVERSITY OF NEBRASKA MEDICAL CENTER   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

6 CARBOXYFLUORESCEIN; CALCEIN; CATIONIC SURFACTANT; COPOLYMER; MACROGOL; POLYACRYLIC ACID; POLYMER; POLYMETHACRYLIC ACID; POLYSTYRENE;

AQUEOUS SOLUTION; COMPLEX FORMATION; DRUG DELIVERY SYSTEM; ELECTRON MICROSCOPY; GENE TARGETING; LETTER; SPECTROFLUOROMETRY; ZETA POTENTIAL;

EID: 0032581954     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja981922t     Document Type: Letter

References (16)

1. Kwon, G.S.; Kataoka, K. Adv. Drug. Deliv. Rev. 1995, 16, 295-309.
2. Kabanov, A. V.; Feigner, P. L.; Seymour, L. W., Eds.; Self-assembling complexes for gene delivery. From laboratory to clinical trial. John Wiley & Sons: New York, 1998.
3. 16PyBr). The complexes were prepared by mixing PEO-b-PMANa and surfactant aqueous solutions at room temperature in the absence of added elctrolyte. In all cases, the final concentration of the PEO-b-PMANa carboxylate groups was 0.6 mM, the [surfactant]/[carboxylate group] ratio varied from 0.1 to 1.0, pH 8.4 to 8.6. No additional mechanical agitation commonly used for vesicle preparation was applied.
4. Particle ζ-potential was measured as previously described (Bronich, T. K.; Kabanov, A. V.; Kabanov, V. A.; Yu, K.; Eisenberg, A. Macromolecules 1997, 30, 3519-3525).
5. Khougaz, K.; Astafieva, I.; Eisenberg, A. Macromolecules 1995. 28, 7135-7147.
6. For the negative staining experiment, a drop of sample solution was settled on a Formvar-coated EM grid for 1 min. Excess sample was wicked away with filter paper, and a drop of staining solution (aqueous 1% uranyl acetate or 1% ammonium molybdate) was allowed to contact the sample for 1 min. The samples were analyzed using a Philips 410 TEM microscope. For freeze fracture, samples were loaded in winged double replica holders and frozen by plunging into liquid propane. After freezing, the samples were fractured in a Balzers 301 freeze fracture apparatus at-110 °C, followed by platinum/carbon replication. Replicas were washed in 1:1:1 mixture of acetic: nitric:sulfuric acids, rinsed in distilled water, and picked up on 200-mesh copper grids. The images of the replicas were recorded using a Hitachi H-600 TEM microscope.
7. Johnson, S. M.; Bangham, A. D.; Hill, M. W.; Korn, E. D. Biochim. Biophys. Acta 1971, 233, 820-825.
8. Stoichiometric complexes prepared in the presence of the dye (10 mM CF or 0.1 mM calcein) were separated from nonentrapped dye by gel penetration chromatography on Sephadex G-25 equilibrated with 0.01 mM solutions of the surfactant. The vesicles disintegrated in the presence of Triton X-100 (0.16%) as shown by photon correlation spectroscopy. This was accompanied by the release of CF in the external solution as evidenced by an increase in fluorescence resulting from the dye dilution (de la Maza, A.; Parra, J. L.; Leal, J. S. Langmuir 1992, 8, 2422-2426).
9. 2+ ions (Oku, N.; Kendall, D. A.; Macdonald, R. C. Biochim. Biophys. Acta 1982, 691, 332-340). The residual fluorescence corresponding to calcein entrapped in the vesicles (2% of the initial value) quenched after vesicle disintegration by Triton X-100.
10. Zhang, L.; Eisenberg, A. Science 1995, 268, 1728-1731.
11. The wall thickness was determined using 46 measurements randomly collected from four ammonium molybdate TEM images using the Image Pro Plus program (Media Cybernetics).
12. In the solid state, regular complexes organize into lamellae consisting of alternating layers of polymer chains separated by layers of surfactant molecules (Khandurina, Y. V.; Dembo, A. T.; Rogacheva, V. B.; Zezin, A. B.; Kabanov, V. A. Polym. Sci. U.S.S.R. 1994, 36, 189-194.).
13. McIntoch, T. J.; Kenworthy, A. K.; Needham, D. Stealth Liposomes, Lasic, D., Martin, F., Eds.: CRS Press: Boca Raton, 1995; pp 63-71. The thickness of PEO layers in Stealth liposomes was compared at PEO. Iipid molar ratio ca. 1 % which is close to the PEO:surfactant ratio in the studied complexes.
14. Kaler, E. W.; Murthy, A. K.; Rodriguez, B. E.; Zasadzinski, J. A. Science 1989, 245, 1371-1374.
15. Szleifer, I.; Gerasimov, O. V.; Thompson, D. H. Proc. Natl. Acad. Sci. U.S.A. 1998, 95, 1032-1037.
16. Effective diameters were determined by photon correlation spectroscopy using a “ZetaPlus” ζ-potential analyzer (Brookhaven Instrument Co.) equipped with the multiangle option. The sizing measurements were performed in aqueous solutions ([COONa] = [surfactant] = 0.6 mM) at 25 °C at a detection angle of 90°. Polydispersity indexes were less than 0.1, indicating narrow size distribution.