Chloride transporters have been intensely investigated because of their potential medicinal applications. In particular, pH-switchable transporters are highly appealing as potential anticancer agents, because they might be more active in cancer cells than in normal cells. Owing to its increased acidity, our simple 3,6-dinitro substituted carbazole receptor acts as a pH-switchable transporter, with physiologically relevant apparent pK_a of 6.4. Read more in our newest paper in special issue of Frontiers in Chemistry, devoted to anion transport:

Maslowska-Jarzyna, M. L. Korczak, M. J. Chmielewski, “Boosting Anion Transport Activity of Diamidocarbazoles by Electron Withdrawing Substituents” Front. Chem., 2021, 9:690035.

We invite students interested in collaboration on a ground-breaking research project on the border of organic and material chemistry. Attractive fellowships are available!

Electrically conductive metal-organic frameworks (MOFs) are a fascinating class of porous conductors with many potential applications, such as chemiresistive sensing, electrochemical energy storage, and electrocatalysis. Owing to the Bekker fellowship from the Polish National Agency for Academic Exchange (NAWA), Dr. Michał Chmielewski spent 7 months in the laboratory of one of the pioneers and leaders of the development of these materials, prof. Mircea Dincă from Massachusetts Institute of Technology. The first results of this collaboration have just appeared in Angewandte Chemie International Edition:

Drugs, metabolites, and other biologically relevant anionic species can be rapidly transported through biological membranes by a simple di(thioamide) receptor developed in our laboratory. In collaboration with the group of professor Alexander Kros from Leiden University, we have also shown that the transport kinetics of these anions can be easily quantified in both large and giant unilamellar vesicles (LUVs and GUVs).

Most anions are too hydrophilic to spontaneously migrate through lipid bilayers. At the same time, however, their transport is necessary for life. For example, cellular respiration – a complex biochemical process through which every living cell produces energy – involves the facilitated transport of chloride, bicarbonate as well as various carboxylates and phosphates across lipid bilayers. In cells, this is usually accomplished by specialised proteins, and hence their dysfunction can cause serious diseases. Accordingly, the development of artificial anion transporters (anionophores) is currently a “hot topic” in supramolecular chemistry.

Fig. 1. Anion transport through lipid bilayers of synthetic liposomes facilitated by synthetic transporters

Surprisingly however, most of the previous studies in this field were focused on chloride transporters, even though in Nature the transport of other anions also plays a significant role. This is most probably due to the lack of direct and convenient methods to follow the transport of other anions. Our new project aims to develop new, direct methods of measuring anion transport for a broad range of biologically important anions and to use these methods to develop selective artificial anion transporters. One particularly ambitious goal of this project is to develop enantioselective anion transporters, an achievement which has no precedents in literature thus far.

Small molecules able to selectively transport biologically relevant anions, such as basic forms of amino acids, nucleotides, metabolites or drugs, may have interesting biological activity and may find applications in medicine, sensor technology and separation of mixtures, including the mixtures of enantiomers.

Currently, we are looking for prospective MSc and PhD students as well as postdoctoral researchers willing to join the project. We offer state-of-the-art research facilities and attractive fellowships! For more details, contact me via e-mail: mchmielewski@chem.uw.edu.pl or follow the News section on the main page.

PhD and MSc positions are available within ‘OPUS’ grant from the Polish National Science Centre. The aim of the project is to create a revolutionary new class of ‘intelligent’ MOFs, able to adapt to their environment in response to external physical or chemical stimuli (see the scheme below).

Dr Michał Chmielewski was granted a Bekker scholarship from the National Agency for Academic Exchange, thanks to which he will spend 7 months in one of the world’s best universities – the Massachusetts Institute of Technology. During this time, he will work in the Mircea Dinca group on new types of conductive MOFs.