Self-Assembled Metal–Phenolic Networks on Emulsions as Low-Fouling and pH-Responsive Particles

Quinn A. Besford, Yi Ju, Ting Yi Wang, Gyeongwon Yun, Pavel V. Cherepanov, Christoph E. Hagemeyer, Francesca Cavalieri, Frank Caruso

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)


Interfacial self-assembly is a powerful organizational force for fabricating functional nanomaterials, including nanocarriers, for imaging and drug delivery. Herein, the interfacial self-assembly of pH-responsive metal–phenolic networks (MPNs) on the liquid–liquid interface of oil-in-water emulsions is reported. Oleic acid emulsions of 100–250 nm in diameter are generated by ultrasonication, to which poly(ethylene glycol) (PEG)-based polyphenolic ligands are assembled with simultaneous crosslinking by metal ions, thus forming an interfacial MPN. PEG provides a protective barrier on the emulsion phase and renders the emulsion low fouling. The MPN-coated emulsions have a similar size and dispersity, but an enhanced stability when compared with the uncoated emulsions, and exhibit a low cell association in vitro, a blood circulation half-life of ≈50 min in vivo, and are nontoxic to healthy mice. Furthermore, a model anticancer drug, doxorubicin, can be encapsulated within the emulsion phase at a high loading capacity (≈5 fg of doxorubicin per emulsion particle). The MPN coating imparts pH-responsiveness to the drug-loaded emulsions, leading to drug release at cell internalization pH and a potent cell cytotoxicity. The results highlight a straightforward strategy for the interfacial nanofabrication of pH-responsive emulsion–MPN systems with potential use in biomedical applications.

Original languageEnglish
Article number1802342
Number of pages9
Issue number39
Publication statusPublished - 27 Sep 2018


  • drug delivery
  • emulsion
  • metal–phenolic networks
  • nanomaterials
  • self-assembly

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