Researchers at the Department of Molecular Nanofabrication have published their preliminary results on “coupling chemistry at protein level”. This work was carried out in the context of a European Research Council (ERC) project. The leader of the research team, Dr. Pascal Jonkheijm, explains that “Our approach to coupling chemistry at protein level worked so well that we immediately went one step further. Now we can use supramolecules to electrically switch the behavior of individual cells. This occurs under the same physiological conditions as those found in the body.” The trick is to bind ligands (antibodies) to diseased cells. The success or failure of this approach is not simply a question of pure chemistry. It also depends on the, occasionally indefinable, “watery” conditions around the cell.
An external electric field determines whether the cells bind to the ligands or unbind from them. The experiments carried out by the University of Twente researchers involved an order of magnitude of 0.4 V. On a specially prepared surface, a “wound” inflicted on a cell-covered substrate healed significantly faster than it would under normal conditions in a healthy body.
Electrochemically activated cell release is achieved using a redox-active supramolecular complex. Host molecule CB (green) links surface-bound viologen (purple) with solution-exposed RGD peptides (red). Electrochemical reduction dissociates the complex, releases the peptides, and thus releases the cells from the substrates. This supramolecular strategy is also applicable to microelectrodes. Credit: Wiley
The star of the show in this approach is that the links appear to be reversible. Reversing the electrical signal causes cells to bind or to unbind. In some cases it is possible to partially bind the cells.
“This research opens the way to studies of fundamental aspects of cell biology” says, Dr. Pascal Jonkheijm, the leader of the research team.
There is a hope to considering this method to possible applications:
1. to attach the molecules to platforms carrying various ligands, which we can then present dynamically in terms of time and place.
2. also to see whether this method might be useful for detecting specific cells, using “cell fingerprints”.
Note: In the case of regeneration, for example, natural factors often play a decisive part. For instance, in the worst case, any infections that develop during treatment can lead to rejection. In such situations, the ability to control events at the cellular level is an important tool.”
The article was published in Angewandte Chemie.