Abstract
Surfactant bilayers in aqueous media interact non-specifically via long range electrostatic, electrodynamic, and solvation forces.1–5 Even though the magnitude of each interaction can be very large, the free energy minimum at stable contact is usually small with a progressive increase in depth as bilayer separation decreases. Addition of large, non-adsorbing polymers (e.g. dextran or polyethylene oxide) can greatly augment the weak natural attraction between bilayers to force them into closer proximity (perhaps sufficiently close to facilitate fusion). With micromechanical experiments on giant bilayer vesicles, direct measurements are made of free energy potentials for assembly of two bilayers to adhesive contact in salt solutions and in concentrated polymer solutions.6–14 Results for neutral and charged lipid bilayers in salt buffer correlate well with classical prescriptions for van der Waals attraction and electric double-layer repulsion based on structural data derived from published X-ray diffraction studies. Adhesion in concentrated solutions of non-adsorbing polymers is promoted by interaction of depletion layers due to polymer exclusion from the bilayer surfaces. For equilibrium exchange of polymer between the gap and bulk regions, the added attraction is shown to be simply the osmotic pressure difference between the bulk polymer concentration and the depreciated value at the mid-point of bilayer separation.
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References
E.J.W. Verwey and J.Th.G. Overbeek: Theory of the Stability of Lyophobic Colloids (Elsevier, Amsterdam, 1948).
V.A. Parsegian, N. Fuller and R.P. Rand: Proc. Natl. Acad. Sci. USA. 76, 2750 (1979).
V.A. Parsegian: Ann. Rev. BioPhys. Bioeng.. 2, 221 (1973).
J.N. Israelachvili and R.M. Pashley: In Biophysics of Water, F. Franks Ed. (John Wiley and Sons, 1982) p. 183.
R.P. Rand: Ann. Rev. BioPhys. Bioeng.. 10, 277 (1981).
E. Evans: Colloids and Surfaces 1984, 10, 133.
E. Evans and M. Metcalfe: Biophys. J.. 45, 715 (1984).
R. Kwok and E. Evans: Biophys. J., 35, 637 (1981).
E. Evans and D. Needham: Faradav Discuss. Chem. Soc., No. 81 (1987).
E. Evans and D. Needham: J. Phys. Chem. (in press).
E. Evans: BioPhys. J. 1980, 31, 425.
E. Evans and V.A. Parsegian: In Surface Phenomena in Hemorheologv: Theoretical ExperimentalT and Clinical Aspects; Copley, A.L., Seaman, G.V.F., Eds. (N.Y. Acad. Sci., 1983) p. 13.
E. Evans and M. Metcalfe: BioPhys. J., 46, 423 (1984).
E. Evans and D. Needham: Macromolecules (submitted).
E.M. Lifshitz: J. Exp. Theor. Phys. USSR, 29, 94 (1955); Sov. Phys. JETP, 2, 73 (1956).
L.J. Lis, M. McAlister, N. Fuller and R.P. Rand: Biophys. J.. 37, 657 (1982).
W. Helfrich: Z. Naturforsch, 33a, 305 (1978).
E. Evans and V.A. Parsegian: Proc. Natl. Acad. Sci. USAT 83, 7132 (1986).
E. Evans and R. Skalak: Mechanics and Thermodynamics of Biomembranes (CRC Press, Boca Raton, Fla., 1980).
V. Luzzati: In Biological Membranes, D. Chapman Ed. (Academic Press, New York, 1968) p. 71.
E. Evans, D. Needham and R.P. Rand: Colloids and Surfaces (to be submitted).
R.P. Rand and V.A. Parsegian: (to be submitted).
D. Le Neveu, R.P. Rand, D. Gingell and V.A. Parsegian: Biophys. J., 18, 209 (1977).
B.W. Ninham and V.A. Parsegian: J. Chem. Phys.. 53, 3398 (1970).
J. Marra: J. Colloid Interface Sci., 107, 446 (1985)
M. Hauser, I. Pascher, R.M. Pearson and S. Sundell: Biochim et BioPhys. Acta, 650, 21 (1981).
T.J. Mcintosh and S.A. Simon: Biochem., 25, 4058 (1986).
V.A. Parsegian: Private Communication; and V.A. Parsegian: Ann. Rev. Biophys. Bioeng. 1973, 2, 221.
J. Marra and J. Israelachvili: Biochem., 24, 4608 (1985).
Double-layer repulsion has been modelled by the full-nonlinear Poisson-Boltzmann equations and Guoy-Chapman theory.1 For these small charge contents, linearized equations are completely acceptable. Also, Na+ binding to the (PS + PC) bilayers is well-established and is characterized by an equilibrium constant of 0.6 M−1.31
M. Eisenberg, T. Gresalfi, T. Riccio and S. McLaughlin: Biochem., 18, 3213 (1979).
J.F. Joanny, L. Leibler and P-G. de Gennes: J. Polym. Sci. Polym. Phys. Ed. 1979, 17, 1073.
G.J. Fleer, J.M.H.M. Scheutjens and B. Vincent: In Polymer Adsorption and Dispersion Stability, Goddard, E.D., Vincent, B., Eds. (Am. Chem. Soc, Washington, 1984) p. 245.
Th.F. Tadros: In Polymer Colloids, Buscall, R., Corner, T., Stageman, J.F., Eds. (Elsevier Applied Sci., London, 1985) p. 105.
B. Vincent: In Polymer Adsorption and Dispersion Stability, Goddard, E.D., Vincent, B., Eds. (Am. Chem. Soc, Washington, 1984) p. 1
D.H. Napper: Polymeric Stabilization of Colloidal Dispersions, Academic Press, London, 1983.
P-G. de Gennes: J. Phys. (Paris) 1976, 37, 1445.
P-G. de Gennes: Macromolecules 1982, 15, 492.
J.M.H.M. Scheutjens and G.J. Fleer: Macromolecules 1985, 18, 182.
E. Mackor, and J. van der Waals: J. Colloid Sci. 1952, 7, 535.
S. Ash and G. Findenegg: Trans. Faradav Soc. 1971, 67, 2122.
S.F. Edwards: Proc. Phys. Soc. (London) 1965, 85, 613.
A. Silberberg: J. Chem. Phys. 1967, 46, 1105; 1968, 48, 2835.
R.J. Roe: J. Chem. Phys. 1974, 60, 4192.
P-G. de Gennes: Scaling Concepts in Polymer Physics (Cornell University Press, Ithaca, 1979).
J.M.H.M. Scheutjens and G.F. Fleer: Adv. Colloid Interface Sci. 1982, 16, 361; 1983, 18, 309.
J.W. Cahn and J.E. Hilliard: J. Chem. Phys. 1958, 28, 258.
G. Widom: Physica 1979, 95A, 1.
Note: all chemical potentials and free energies are assumed to be in units of thermal energy, i.e. normalized by kT.
P.J. Flory: Principles of Polymer Chemistry (Cornell University Press, Ithaca, 1953).
Note: The data required for these predictions are νs = 29.9 x 10-24 cm3; νm = 164 x 10-24 cm3; am=νm 1/3 = 5.47 x 10-8cm; Np = Mn/162; and the virial coefficients for each polymer fraction taken from Table 2
The number-average molecular weights for the larger fractions could not be accurately measured by osmotic pressure methods; hence the values given in Table 2 for the first virial coefficient are those measured by the producers.
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Evans, E., Needham, D. (1988). Intrinsic Colloidal Attraction/Repulsion between Lipid Bilayers and Strong Attraction Induced by Non-adsorbing Polymers. In: Ohki, S., Doyle, D., Flanagan, T.D., Hui, S.W., Mayhew, E. (eds) Molecular Mechanisms of Membrane Fusion. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-1659-6_7
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DOI: https://doi.org/10.1007/978-1-4613-1659-6_7
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