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Yusuf Hamied Department of Chemistry


Courtesy Nitschke group

A research article by members of the Nitschke group has been chosen the ChemSci Pick of the Week for the journal Chemical Science.

In Waterproof Architectures through Subcomponent Self-Assembly, published today in Chemical Science, the team describes how to make “submarine-like” cages, which have the potential to transport target molecules, for example to deliver drugs, remove pollutants, transport dyes for diagnostic imaging, and other useful applications.

Metal-organic cages are a new family of materials that can selectively trap guest molecules for transport, storage or chemical transformation under controlled conditions.  These “nanocontainers” could allow scientists to build sophisticated systems for sensing specific molecules or environmental pollutants present in the bloodstream in the context of clinical diagnosis, or for transporting dyes for diagnostic imaging, among other uses.

Chemists create the cages synthetically by causing rationally designed organic building blocks to self-assemble around positively-charged metal ions. But until now, the development of new applications for these cages in biological, medical, environmental and industrial domains has been limited by the difficulty of constructing molecular cages that are soluble and stable in water.

“The preparation of cages that are soluble and stable in water has been a major challenge,” says lead author Edmundo Guzman-Percastegui, a postdoctoral researcher in the Nitschke group.  But in the publication Edmundo and fellow researchers Jesús Mosquera, Tanya Ronson, Alex J. Plajer and Marion Kieffer, present a blueprint for the straightforward preparation of water-soluble metal-organic cages of varied shapes and sizes, overcoming the solubility and stability issues that have plagued previous attempts, and omitting the laborious synthesis of water-soluble organic ligands.  They describe how they were able to “tune” the aqueous stability and solubility of the cages by carefully selecting the metal ion, building block and negatively-charged counter-ions.

“Put simply, the water-soluble and waterproof cages we have prepared are like submarines, equipped with a robust hull and internal storage designed to be submerged in the water for long periods, to bring target molecules to their destinations.” says Edmundo.

The study represents a significant step forward in the design of abiological architectures able to trap, transport or transform chemicals in water or physiological media.

“Since our cages have both solubility and stability in water, they could eventually find broad applications for medicine, environmental remediation, and chemical purification,” says group leader Professor Jonathan Nitschke.

ChemSci Pick of the Weeks are a way for the editorial team at Chemical Science to select and share their favourite articles with the wider chemical community. All ChemSci Picks are also added to an on-going collection on their "Pick of the Week" pages.

Waterproof Architectures through Subcomponent Self-Assembly, Edmundo Percastegui, Jesus Mosquera, Tanya Ronson, Alex J. Plajer, Marion Kieffer and Jonathan Nitschke, Chem. Sci. (2019).