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 and enhanced biocidal activity of water-dispersable organic nanoparticles

Abstract

Water-insoluble organic compounds are often used in aqueous environments in various pharmaceutical and consumer products. To overcome insolubility, the particles are dispersed in a medium during product formation1, but large particles that are formed may affect product performance and safety. Many techniques have been used to produce nanodispersions—dispersions with nanometre-scale dimensions—that have properties similar to solutions2,3,4. However, making nanodispersions requires complex processing, and it is difficult to achieve stability over long periods1. Here we report a generic method for producing organic nanoparticles with a combination of modified emulsion-templating5 and freeze-drying. The dry powder composites formed using this method are highly porous, stable and form nanodispersions upon simple addition of water. Aqueous nanodispersions of Triclosan (a commercial antimicrobial agent) produced with this approach show greater activity than organic/aqueous solutions of Triclosan.

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

Access options

Buy this article

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

Figure 1: Characterization of solid nanocomposites and nanodispersions.
Figure 2: Comparison of conventional surfactant solubilization and nanodispersions of Oil-Red (OR).
Figure 3: Schematic/mechanistic representation of nanoparticle formation during freeze-drying.
Figure 4: Scanning electron microscopy images of freeze-dried atomized powders.
Figure 5: Evaluation of the minimum inhibitory concentration (MIC) of different forms of the antibacterial agent Triclosan.

Similar content being viewed by others

References

  1. Abdelwahed, W., Degobert, G., Stainmesse, S. & Fessi, H. Freeze-drying of nanoparticles: Formulation, process and storage considerations. Adv. Drug Deliv. Rev. 58, 1688–1713 (2006).

    Article  Google Scholar 

  2. Mizoe, T., Ozeki, T. & Okada, H. Preparation of drug nanoparticle-containing microparticles using a 4-fluid nozzle spray drier for oral, pulmonary and injection dosage forms. J. Contr. Rel. 122, 10–15 (2007).

    Article  Google Scholar 

  3. Texter, J. Precipitation and condensation of organic particles. J. Disp. Sci. Technol. 22, 499–527 (2001).

    Article  Google Scholar 

  4. Horn, D. & Rieger, J. Organic nanoparticles in the aqueous phase—theory, experiment and use. Angew. Chem. Int. Ed. Engl. 40, 4330–4361 (2001).

    Article  Google Scholar 

  5. Zhang, H. & Cooper, A. I. Synthesis and applications of emulsion-templated porous materials. Soft Matter 1, 107–113 (2005).

    Article  Google Scholar 

  6. Royal Society and Royal Academy of Engineering Nanoscience and Nanotechnologies. Nanoscience and Nanotechnologies: Opportunities and Uncertainties, Report (Royal Society and Royal Academy of Engineering Nanoscience and Nanotechnologies, 2004) <http://www.nanotec.org.uk/finalReport.htm>.

    Google Scholar 

  7. Rabinow, B. E. Nanosuspensions in drug delivery. Nature Rev. Drug Discov. 3, 785–796 (2004).

    Article  Google Scholar 

  8. Galindo-Rodríguez, S. A. et al. Comparative scale-up of three methods for producing ibuprofen-loaded nanoparticles. Eur. J. Pharm. Sci. 25, 357–367 (2005).

    Article  Google Scholar 

  9. Lee, J. C. et al. Preparation, stability and in vitro performance of vesicles made with diblock copolymers. Biotechnol. Bioeng. 73, 135–145 (2001).

    Article  Google Scholar 

  10. Sethi, V., Önyüksel, H. & Rubinstein, I. Liposomal vasoactive intestinal peptide. Method. Enzymol. 391, 377–395 (2005).

    Article  Google Scholar 

  11. Kita-Tokarczyk, K., Grumelard, J., Haefele, T. & Meier, W. Block copolymer vesicles — using concepts from polymer chemistry to mimic biomembranes. Polymer 46, 3540–3563 (2005).

    Article  Google Scholar 

  12. Cameron, N. R. High internal phase emulsion templating as a route to well-defined porous polymers. Polymer 46, 1439–1449 (2005).

    Article  Google Scholar 

  13. Dwivedi, A. M. Residual solvent analysis in pharmaceuticals. Pharm. Technol. Eur. 14, 26–28 (2002).

    Google Scholar 

  14. Gilanyi, T. & Wolfram, E. Interaction of ionic surfactants with polymers in aqueous solution. Coll. Surf. 3, 181–198 (1981).

    Article  Google Scholar 

  15. Tang, X. & Pikal, M. J. Design of freeze-drying processes for pharmaceuticals: practical advice. Pharm. Res. 21, 191–200 (2004).

    Article  Google Scholar 

  16. Franks, F. Freeze-drying of bioproducts: putting principles into practice. Eur. J. Pharm. Biopharm. 45, 221–229 (1998).

    Article  Google Scholar 

  17. Craig, D. Q. M., Royall, P. G., Kett, V. L. & Hopton, M. L. The relevance of the amorphous state to pharmaceutical dosage forms: glassy drugs and freeze-dried systems. Int. J. Pharm. 179, 179–207 (1999).

    Article  Google Scholar 

  18. Zhang, H. et al. Aligned two- and three-dimensional structures by directional freezing of polymers and nanoparticles. Nature Mater. 4, 787–793 (2005).

    Article  Google Scholar 

  19. Yu, Z., Rogers, T. L., Hu, J., Johnston, K. P. & Williams, R. O. Preparation and characterization of microparticles containing peptide produced by a novel process: spray freezing into liquid. Eur. J. Pharm. Biopharm. 54, 221–228 (2002).

    Article  Google Scholar 

  20. Rogers, T. L. et al. Micronized powders of a poorly water soluble drug produced by a spray-freezing into liquid-emulsion process. Eur. J. Pharm. Biopharm. 55, 161–172 (2003).

    Article  Google Scholar 

  21. Skrabalak, S. E. & Suslick, K. S. Porous MoS2 synthesized by ultrasonic spray pyrolysis. J. Am. Chem. Soc. 127, 9990–9991 (2005).

    Article  Google Scholar 

  22. Iskandar, F., Mikrajuddin & Okuyama, K. Controllability of pore size and porosity on self-organized porous silica particles. Nano Lett. 2, 389–392 (2002).

    Article  Google Scholar 

  23. Suh, W. H. & Suslick, K. S. Magnetic and porous nanospheres from ultrasonic spray pyrolysis. J. Am. Chem. Soc. 127, 12007–12010 (2005).

    Article  Google Scholar 

  24. DeSimone, J. M. Practical approaches to green solvents. Science 297, 799–803 (2002).

    Article  Google Scholar 

  25. Cooper, A. I. Porous materials and supercritical fluids. Adv. Mater. 15, 1049–1059 (2003).

    Article  Google Scholar 

  26. Zhang, H., Long, J. & Cooper, A. I. Aligned porous materials by directional freezing of solutions in liquid CO2 . J. Am. Chem. Soc. 127, 13482–13483 (2005).

    Article  Google Scholar 

  27. Butler, R., Hopkinson, I. & Cooper, A. I. Synthesis of porous emulsion-templated polymers using high internal phase CO2-in-water emulsions. J. Am. Chem. Soc. 125, 14473–14481 (2003).

    Article  Google Scholar 

  28. Tan, B. & Cooper, A. I. Functional oligo(vinyl acetate) CO2-philes for solubilization and emulsification. J. Am. Chem. Soc. 127, 8938–8939 (2005).

    Article  Google Scholar 

  29. Taylor, T. J. et al. Physicochemical factors affecting the rapid bactericidal efficacy of the phenolic antibacterial triclosan. Int. J. Cosmetic Sci. 26, 111–116 (2004).

    Article  Google Scholar 

Download references

Acknowledgements

The authors thank IOTA NanoSolutions Limited for an Industrial Senior Research Fellowship (S.R.), the Royal Society for a University Research Fellowship (A.C.) and an Industry Fellowship (S.R.) and Research Councils UK for an Academic Fellowship (H.Z.). We also acknowledge the Centre for Materials Discovery (University of Liverpool) for access to analytical equipment and specifically J. Weaver for help conducting surface tension measurements. The EPSRC (grant GR/N39999/01 and Portfolio Partnership in Complex Materials Discovery EP/C511794/1), IOTA NanoSolutions Limited and Unilever are thanked for financial support.

Author information

Authors and Affiliations

Authors

Contributions

All authors contributed to the experimental programme, either through design of the experiment or practice. D.T. led the microbiological testing. H.Z., A.C. and S.R. co-wrote the manuscript.

Corresponding authors

Correspondence to Andrew I. Cooper or Steven P. Rannard.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Zhang, H., Wang, D., Butler, R. et al. Formation and enhanced biocidal activity of water-dispersable organic nanoparticles. Nature Nanotech 3, 506–511 (2008). https://doi.org/10.1038/nnano.2008.188

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2008.188

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing