Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Formation of droplet networks that function in aqueous environments

Nature Nanotechnology volume 6, pages 803–808 (2011)Cite this article

Subjects

Abstract

Aqueous droplets in oil that are coated with lipid monolayers and joined through interface bilayers1,2 are useful for biophysical measurements on membrane proteins2,3,4,5. Functional networks of droplets that can act as light sensors, batteries and electrical components can also be made by incorporating pumps, channels and pores into the bilayers2,6. These networks of droplets mimic simple tissues7, but so far have not been used in physiological environments because they have been constrained to a bulk oil phase. Here, we form structures called multisomes in which networks of aqueous droplets with defined compositions are encapsulated within small drops of oil in water. The encapsulated droplets adhere to one another and to the surface of the oil drop to form interface bilayers that allow them to communicate with each other and with the surrounding aqueous environment through membrane pores. The contents in the droplets can be released by changing the pH or temperature of the surrounding solution. The multicompartment framework of multisomes mimics a tissue7,8,9 and has potential applications in synthetic biology and medicine.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Schematics and photographs of multisomes.
Figure 2: Free energy landscape.
Figure 3: Measurement of ionic currents through αHL pores.
Figure 4: Communication by diffusion through αHL pores.
Figure 5: pH- and temperature-dependent release of encapsulated contents into the aqueous environment.

Similar content being viewed by others

References

  1. Funakoshi, K., Suzuki, H. & Takeuchi, S. Lipid bilayer formation by contacting monolayers in a microfluidic device for membrane protein analysis. Anal. Chem. 78, 8169–8174 (2006).

    Article  CAS  Google Scholar 

  2. Holden, M. A., Needham, D. & Bayley, H. Functional bionetworks from nanoliter water droplets. J. Am. Chem. Soc. 129, 8650–8655 (2007).

    Article  CAS  Google Scholar 

  3. Heron, A. J., Thompson, J. R., Mason, A. E. & Wallace, M. I. Direct detection of membrane channels from gels using water-in-oil droplet bilayers. J. Am. Chem. Soc. 129, 16042–16047 (2007).

    Article  CAS  Google Scholar 

  4. Syeda, R., Holden, M. A., Hwang, W. L. & Bayley, H. Screening blockers against a potassium channel with a droplet interface bilayer array. J. Am. Chem. Soc. 130, 15543–15548 (2008).

    Article  CAS  Google Scholar 

  5. Heron, A. J., Thompson, J. R., Cronin, B., Bayley, H. & Wallace, M. I. Simultaneous measurement of ionic current and fluorescence from single protein pores. J. Am. Chem. Soc. 131, 1652–1653 (2009).

    Article  CAS  Google Scholar 

  6. Maglia, G. et al. Droplet networks with incorporated protein diodes show collective properties. Nature Nanotech. 4, 437–440 (2009).

    Article  CAS  Google Scholar 

  7. Woolfson, D. N. & Bromley, E. H. C. Synthetic biology. The Biochemist 19–25 (February 2011).

  8. Channon, K., Bromley, E. H. C. & Woolfson, D. N. Synthetic biology through biomolecular design and engineering. Curr. Opin. Struct. Biol. 18, 491–498 (2008).

    Article  CAS  Google Scholar 

  9. Solé, R. V., Munteanu, A., Rodriguez-Caso, C. & Macía, J. Synthetic protocell biology: from reproduction to computation. Phil. Trans. R. Soc. B 362, 1727–1739 (2007).

    Article  Google Scholar 

  10. Walker, S. A., Kennedy, M. T. & Zasadzinski, J. A. Encapsulation of bilayer vesicles by self-assembly. Nature 387, 61–64 (1997).

    Article  CAS  Google Scholar 

  11. Kim, S., Turker, M. S., Chi, E. Y., Sela, S. & Martin, G. M. Preparation of multivesicular liposomes. Biochim. Biophys. Acta Biomembranes 728, 339–348 (1983).

    Article  CAS  Google Scholar 

  12. Yue, B. Y., Jackson, C. M., Taylor, J. A. G., Mingins, J. & Pethica, B. A. Phospholipid monolayers at non-polar oil/water interfaces. Part 1—Phase transitions in distearoyl-lecithin films at the n-heptane aqueous sodium chloride interface. J. Chem. Soc. Farad. Trans. I 72, 2685–2693 (1976).

    Article  CAS  Google Scholar 

  13. Morisaku, T., Yui, H. & Sawada, T. Development of a new experimental system for monitoring biomembrane reactions: combination of laser spectroscopic techniques and biomembrane models formed at an oil/water interface. Anal. Sci. 20, 1605–1608 (2004).

    Article  CAS  Google Scholar 

  14. Needham, D. & Haydon, D. A. Tensions and free energies of formation of ‘solventless’ lipid bilayers—measurement of high contact angles. Biophys. J. 41, 251–257 (1983).

    Article  CAS  Google Scholar 

  15. Stoddart, D., Heron, A. J., Mikhailova, E., Maglia, G. & Bayley, H. Single-nucleotide discrimination in immobilized DNA oligonucleotides with a biological nanopore. Proc. Natl Acad. Sci. USA 106, 7702–7707 (2009).

    Article  CAS  Google Scholar 

  16. Gu, L.-Q. & Bayley, H. Interaction of the noncovalent molecular adapter, β-cyclodextrin, with the staphylococcal α-hemolysin pore. Biophys. J. 79, 1967–1975 (2000).

    Article  CAS  Google Scholar 

  17. Drummond, D. C., Zignani, M. & Leroux, J.-C. Current status of pH-sensitive liposomes in drug delivery. Prog. Lipid Res. 39, 409–460 (2000).

    Article  CAS  Google Scholar 

  18. Hamilton, J. A. & Cistola, D. P. Transfer of oleic acid between albumin and phospholipid vesicles. Proc. Natl Acad. Sci. USA 83, 82–86 (1986).

    Article  CAS  Google Scholar 

  19. Small, D. M., Cabral, D. J., Cistola, D. P., Parks, J. S. & Hamilton, J. A. The ionization behavior of fatty acids and bile acids in micelles and membranes. Hepatology 4, 77S–79S (1984).

    Article  CAS  Google Scholar 

  20. Mills, J. K. & Needham, D. Lysolipid incorporation in dipalmitoylphosphatidylcholine bilayer membranes enhances the ion permeability and drug release rates at the membrane phase transition. Biochim. Biophys. Acta Biomembranes 1716, 77–96 (2005).

    Article  CAS  Google Scholar 

  21. Nakagawa, S., Maeda, S. & Tsukihara, T. Structural and functional studies of gap junction channels. Curr. Opin. Struct. Biol. 20, 423–430 (2010).

    Article  CAS  Google Scholar 

  22. Strambio-De-Castillia, C., Niepel, M. & Rout, M. P. The nuclear pore complex: bridging nuclear transport and gene regulation. Nature Rev. Mol. Cell Biol. 11, 490–501 (2010).

    Article  CAS  Google Scholar 

  23. Needham, D. & Dewhirst, M. W. The development and testing of a new temperature-sensitive drug delivery system for the treatment of solid tumors. Adv. Drug Deliv. Rev. 53, 285–305 (2001).

    Article  CAS  Google Scholar 

  24. Rautio, J. et al. Prodrugs: design and clinical applications. Nature Rev. Drug Discov. 7, 255–270 (2008).

    Article  CAS  Google Scholar 

  25. Devine, D. V., Wong, K., Serrano, K., Chonn, A. & Cullis, P. R. Liposome-complement interactions in rat serum: implications for liposome survival studies. Biochim. Biophys. Acta Biomembranes 1191, 43–51 (1994).

    Article  CAS  Google Scholar 

  26. Okushima, S., Nisisako, T., Torii, T. & Higuchi, T. Controlled production of monodisperse double emulsions by two-step droplet breakup in microfluidic devices. Langmuir 20, 9905–9908 (2004).

    Article  CAS  Google Scholar 

  27. Chu, L.-Y., Utada, A. S., Shah, R. K., Kim, J.-W. & Weitz, D. A. Controllable monodisperse multiple emulsions. Angew. Chem. Int. Ed. 46, 8970–8974 (2007).

    Article  CAS  Google Scholar 

  28. Seo, M., Paquet, C., Nie, Z., Xu, S. & Kumacheva, E. Microfluidic consecutive flow-focusing droplet generators. Soft Matter 3, 986–992 (2007).

    Article  CAS  Google Scholar 

  29. Shum, H. C., Zhao, Y., Kim, S.-H. & Weitz, D. A. Multicompartment polymersomes from double emulsions. Angew. Chem. Int. Ed. 50, 1648–1651 (2011).

    Article  CAS  Google Scholar 

  30. Debinski, W. & Tatter, S. B. Convection-enhanced delivery for the treatment of brain tumors. Exp. Rev. Neurother. 9, 1519–1527 (2009).

    Article  CAS  Google Scholar 

  31. Larsen, C. et al. Intra-articular depot formulation principles: role in the management of postoperative pain and arthritic disorders. J. Pharm. Sci. 97, 4622–4654 (2008).

    Article  CAS  Google Scholar 

  32. Cheley, S. et al. Spontaneous oligomerization of a staphylococcal α-hemolysin conformationally constrained by removal of residues that form the transmembrane β-barrel. Protein Eng. 10, 1433–1443 (1997).

    Article  CAS  Google Scholar 

  33. Maglia, G., Heron, A. J., Stoddart, D., Japrung, D. & Bayley, H. Analysis of single nucleic acid molecules with protein nanopores. Methods Enzymol. 475, 591–623 (2010).

    Article  CAS  Google Scholar 

  34. Maglia, G. et al. DNA strands from denatured duplexes are translocated through engineered protein nanopores at alkaline pH. Nano Lett. 9, 3831–3836 (2009).

    Article  CAS  Google Scholar 

  35. Abràmoff, M. D., Magalhães, P. J. & Ram, S. J. Image processing with ImageJ. Biophoton. Int. 11, 36–42 (2004).

    Google Scholar 

Download references

Acknowledgements

The authors thank E. Mikhailova for the αHL protein prepared by in vitro transcription/translation, and Q. Li for the αHL from S. aureus. The authors also thank M. Wallace for the loan of a microscope objective. This work was supported by grants from the National Institutes of Health and the European Commission's Seventh Framework Programme Revolutionary Approaches and Devices for Nucleic Acid Analysis Consortium. G.V. was supported by an Engineering and Physical Sciences Research Council Life Sciences Interface Doctoral Training Centre studentship.

Author information

Author notes

  1. Andrew J. Heron

    Present address: Present address: Oxford Nanopore Technologies Ltd, Oxford Science Park, Oxford OX4 4GA, UK,

Authors and Affiliations

  1. Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK

    Gabriel Villar & Hagan Bayley

Authors
  1. Gabriel Villar
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Andrew J. Heron
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Hagan Bayley
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

G.V., A.J.H. and H.B. planned the research. G.V. performed the experiments, data analysis and modelling. G.V. and H.B. wrote the paper.

Corresponding author

Correspondence to Hagan Bayley.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 2355 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Villar, G., Heron, A. & Bayley, H. Formation of droplet networks that function in aqueous environments. Nature Nanotech 6, 803–808 (2011). https://doi.org/10.1038/nnano.2011.183

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2011.183

This article is cited by

Search

Advanced search

Quick links

Nature Briefing: Translational Research

Sign up for the Nature Briefing: Translational Research newsletter — top stories in biotechnology, drug discovery and pharma.

Get what matters in translational research, free to your inbox weekly. Sign up for Nature Briefing: Translational Research