BioPen “paints” ion biosensors onto cells

Being able to monitor signaling events on a cellular level is important for understanding many biological processes. In the paper Immobilization of Recombinant Fluorescent Biosensors Permits Imaging of Extracellular Ion Signals, just published in ACS Sensors, Dr. Roland Malli and coworkers at the Medical University of Graz describe the creation of recombinant fluorescent ion biosensors that bind to cell surfaces and using BioPen to “paint” ion biosensors onto targeted cells.

In their paper, Malli and coworkers present a strategy for creating biosensor applications that uses BioPen to create micropattern in the cell solution in order to enable simultaneous sensing of pH and potassium ions, using two different protein constructs, something which can have interesting applications for cancer research and neuroscience.

To avoid the issue of having intracellular accumulation of biosensors, the researchers instead created a sensor system where the cells express biotin tags that locate to the cell surface and that enables biosensors added to the solution to bind to cell surface.

The researchers use BioPen to create spatially separated microspots containing either of the two biosensors. This allows simultaneous imaging of pH of and potassium ions in a single experiment. The combined sensor approach, using BioPen-based microperfusion to create discrete biosensor regions, can be further expanded to enable a variety of different ratiometric and intentiometric biosensors. Malli and coworkers also points to using the techniques to position biosonensors in selected cell regions such as tumor slices, for instance.

We are very happy that Dr. Rolad Malli and his lab has chosen to use BioPen in their research and we look forward to following their work in the future.