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Spotted vesicles, striped micelles and Janus assemblies induced by ligand binding

Nature Materials volume 8, pages 843–849 (2009)Cite this article

Abstract

Selective binding of multivalent ligands within a mixture of polyvalent amphiphiles provides, in principle, a simple mechanism for driving domain formation in self-assemblies. Divalent cations are shown here to crossbridge polyanionic amphiphiles, which thereby demix from neutral amphiphiles and form spots or rafts within vesicles as well as stripes within cylindrical micelles. Calcium- and copper-crossbridged domains of synthetic block copolymers or natural lipid (phosphatidylinositol-4,5-bisphosphate) possess tunable sizes, shapes and/or spacings that can last for years. Lateral segregation in these ‘ligand-responsive Janus assemblies’ couples weakly to curvature and proves to be restricted within phase diagrams to narrow regimes of pH and cation concentration that are centred near the characteristic binding constants for polyacid interactions. Remixing at high pH is surprising, but a theory for strong lateral segregation shows that counterion entropy dominates electrostatic crossbridges, thus illustrating the insights gained into ligand-induced pattern formation within self-assemblies.

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Figure 1: Spotted vesicles imaged by z-sectioning confocal microscopy during aspiration in micropipettes.
Figure 2: Controlled coarsening yields Janus-like polymersomes.
Figure 3: Fluid–gel transition of a polyanionic polymersome brush with increasing pH or calcium concentration.
Figure 4: Striped cylinder micelles.
Figure 5: Phase diagram with a narrow regime of domain formation for AB1:OB18*=25:75 as observed experimentally and modelled theoretically.

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References

  1. Discher, D. E. & Eisenberg, A. Polymer vesicles. Science 297, 967–973 (2002).

    Article  CAS  Google Scholar 

  2. Pochan, D. J. et al. Toroidal triblock copolymer assemblies. Science 306, 94–97 (2004).

    Article  CAS  Google Scholar 

  3. Won, Y. Y., Davis, H. T. & Bates, F. S. Giant wormlike rubber micelles. Science 283, 960–963 (1999).

    Article  CAS  Google Scholar 

  4. Zhang, L. F., Yu, K. & Eisenberg, A. Ion-induced morphological changes in ‘crew-cut’ aggregates of amphiphilic block copolymers. Science 272, 1777–1779 (1996).

    Article  CAS  Google Scholar 

  5. Fraaije, J., van Sluis, C. A., Kros, A., Zvelindovsky, A. V. & Sevink, G. J. A. Design of chimaeric polymersomes. Faraday Discuss. 128, 355–361 (2005).

    Article  CAS  Google Scholar 

  6. Srinivas, G. & Pitera, J. W. Soft patchy nanoparticles from solution-phase self-assembly of binary diblock copolymers. Nano Lett. 8, 611–618 (2008).

    Article  CAS  Google Scholar 

  7. Walther, A. & Muller, A. H. E. Janus particles. Soft Matter 4, 663–668 (2008).

    Article  CAS  Google Scholar 

  8. Glotzer, S. C. & Solomon, M. J. Anisotropy of building blocks and their assembly into complex structures. Nature Mater. 6, 557–562 (2007).

    Article  Google Scholar 

  9. Alexeev, A., Uspal, W. E. & Balazs, A. C. Harnessing Janus nanoparticles to create controllable pores in membranes. ACS Nano 2, 1117–1122 (2008).

    Article  CAS  Google Scholar 

  10. Cui, H. G., Chen, Z. Y., Zhong, S., Wooley, K. L. & Pochan, D. J. Block copolymer assembly via kinetic control. Science 317, 647–650 (2007).

    Article  CAS  Google Scholar 

  11. Wang, H., Wang, X. S., Winnik, M. A. & Manners, I. Redox-mediated synthesis and encapsulation of inorganic nanoparticles in shell-cross-linked cylindrical polyferrocenylsilane block copolymer micelles. J. Am. Chem. Soc. 130, 12921–12930 (2008).

    Article  CAS  Google Scholar 

  12. Li, Z. B., Kesselman, E., Talmon, Y., Hillmyer, M. A. & Lodge, T. P. Multicompartment micelles from ABC miktoarm stars in water. Science 306, 98–101 (2004).

    Article  CAS  Google Scholar 

  13. Wang, X. S. et al. Cylindrical block copolymer micelles and co-micelles of controlled length and architecture. Science 317, 644–647 (2007).

    Article  CAS  Google Scholar 

  14. Baumgart, T., Hess, S. T. & Webb, W. W. Imaging coexisting fluid domains in biomembrane models coupling curvature and line tension. Nature 425, 821–824 (2003).

    Article  CAS  Google Scholar 

  15. Korlach, J., Schwille, P., Webb, W. W. & Feigenson, G. W. Characterization of lipid bilayer phases by confocal microscopy and fluorescence correlation spectroscopy. Proc. Natl Acad. Sci. USA 96, 8461–8466 (1999).

    Article  CAS  Google Scholar 

  16. Veatch, S. L. & Keller, S. L. Separation of liquid phases in giant vesicles of ternary mixtures of phospholipids and cholesterol. Biophys. J. 85, 3074–3083 (2003).

    Article  CAS  Google Scholar 

  17. Clapham, D. E. Calcium signalling. Cell 131, 1047–1058 (2007).

    Article  CAS  Google Scholar 

  18. Haverstick, D. M. & Glaser, M. Visualization of Ca2+-induced phospholipid domains. Proc. Natl Acad. Sci. USA 84, 4475–4479 (1987).

    Article  CAS  Google Scholar 

  19. Shoemaker, S. D. & Vanderlick, T. K. Calcium modulates the mechanical properties of anionic phospholipid membranes. J. Colloid Interface Sci. 266, 314–321 (2003).

    Article  CAS  Google Scholar 

  20. Geng, Y., Ahmed, F., Bhasin, N. & Discher, D. E. Visualizing worm micelle dynamics and phase transitions of a charged diblock copolymer in water. J. Phys. Chem. B 109, 3772–3779 (2005).

    Article  CAS  Google Scholar 

  21. Horkay, F., Tasaki, I. & Basser, P. J. Effect of monovalent–divalent cation exchange on the swelling of polyacrylate hydrogels in physiological salt solutions. Biomacromolecules 2, 195–199 (2001).

    Article  CAS  Google Scholar 

  22. Konradi, R. & Ruhe, J. Interaction of poly(methacrylic acid) brushes with metal ions: Swelling properties. Macromolecules 38, 4345–4354 (2005).

    Article  CAS  Google Scholar 

  23. Discher, B. M. et al. Cross-linked polymersome membranes: Vesicles with broadly adjustable properties. J. Phys. Chem. B 106, 2848–2854 (2002).

    Article  CAS  Google Scholar 

  24. Gell, C. B., Graessley, W. W. & Fetters, L. J. Viscoelasticity and self-diffusion in melts of entangled linear polymers. J. Polym. Sci. B 35, 1933–1942 (1997).

    Article  CAS  Google Scholar 

  25. Velichko, Y. S. & de la Cruz, M. O. Pattern formation on the surface of cationic–anionic cylindrical aggregates. Phys. Rev. E 72, 041920 (2005).

    Article  CAS  Google Scholar 

  26. Grason, G. M. & Santangelo, C. D. Undulated cylinders of charged diblock copolymers. Eur. Phys. J. E 20, 335–346 (2006).

    Article  CAS  Google Scholar 

  27. Borisov, O. V. & Zhulina, E. B. Reentrant morphological transitions in copolymer micelles with pH-sensitive corona. Langmuir 21, 3229–3231 (2005).

    Article  CAS  Google Scholar 

  28. McLaughlin, S. & Murray, D. Plasma membrane phosphoinositide organization by protein electrostatics. Nature 438, 605–611 (2005).

    Article  CAS  Google Scholar 

  29. Oosawa, F. Polyelectrolytes (M. Dekker, 1971).

    Google Scholar 

Download references

Acknowledgements

The NSF-MRSEC at the University of Pennsylvania provided primary support. Further support from the NIH (D.E.D., P.A.J.), DOE (A.J.L.) and NSF (T.B.) is very gratefully acknowledged. We thank J. D. Pajerowski for his help with correlation length and periodicity analysis.

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Authors and Affiliations

  1. Laboratory for Research on the Structure of Matter, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA

    David A. Christian, Aiwei Tian, Wouter G. Ellenbroek, Ilya Levental, Karthikan Rajagopal, Paul A. Janmey, Andrea J. Liu, Tobias Baumgart & Dennis E. Discher

  2. Chemical & Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA

    David A. Christian, Aiwei Tian, Karthikan Rajagopal & Dennis E. Discher

  3. Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA

    Aiwei Tian & Tobias Baumgart

  4. Physics & Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA

    Wouter G. Ellenbroek, Paul A. Janmey, Andrea J. Liu, Tobias Baumgart & Dennis E. Discher

  5. Bioengineering Graduate Groups, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA

    Ilya Levental, Paul A. Janmey & Dennis E. Discher

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  1. David A. Christian
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Contributions

D.A.C., A.T., I.L., P.A.J., T.B. and D.E.D. designed experiments and analysed data; D.A.C., A.T. and I.L. carried out experiments; W.G.E. and A.J.L. developed the SSL theory; K.R. contributed new reagents; D.A.C., W.G.E., A.J.L., T.B. and D.E.D. wrote the paper.

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Correspondence to Dennis E. Discher.

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Christian, D., Tian, A., Ellenbroek, W. et al. Spotted vesicles, striped micelles and Janus assemblies induced by ligand binding. Nature Mater 8, 843–849 (2009). https://doi.org/10.1038/nmat2512

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