My watch list


Radical Attack on Live Cells

Stimulation of tiny areas on cellular surfaces with free radicals using a microfluidic probe

© Wiley-VCH

08-Apr-2021: Is there a way to chemically manipulate small, confined areas on cellular surfaces? Scientists have developed a microfluidic probe to send a flow of free radicals on live cells and track the outcome using fluorescence imaging. As outlined in the journal Angewandte Chemie, this approach makes it possible for the first time to generate a reaction zone of free radicals with controlled size and concentration for subcellular research.

Free radicals are important stimulants for cells. When live cells are exposed to radicals, they develop intense reactions that can lead to cell injury or even death. Many anticancer drugs are based on the action of free radicals sending cancer cells to death.

However, scientists find it difficult to perform research on the reactions of live cells to radicals in a truly controlled way. Free radicals are unstable and react with their environment before reaching their targets. A team of scientists led by Jin-Ming Lin from Tsinghua University, Beijing, has now developed a microfluidic approach to continuously generate a flow of free radicals for subcellular manipulation.

To make the radicals, the researchers chose a microfluidic two-component system. In this setup, one microchannel harbored a solution of enzymes able to cleave hydrogen peroxide. Another channel contained a solution of hydrogen peroxide and an organic dye. Both channels were immersed with their ends in a nutrient solution where a live cell was placed just below the channel ends. A third channel with an upward flow ensured that the fluids leaving the microchannel ends would meet in the middle position, forming a confined reaction zone.

According to the authors, this setup ensured that the reaction zone had the size of only a few micrometers. In this zone, the enzyme horseradish peroxidase would react with the hydrogen peroxide to form reactive enzyme intermediates, which then reacted with the organic dye to give an organic radical. Immediately after their generation, the dye radicals would then attack the cell placed directly below the reaction zone.

After tens of seconds of component flow and radical attack, the researchers observed that a tiny spot emitting bright red fluorescence had emerged on the cellular membrane. Tracking this spot over time, the researchers found it slowly wandered around on the cellular surface.

The authors say that the tiny fluorescent spot and its movement highlight the ability of the microfluidic method to manipulate small subareas on the cell surface. “By contrast with lipophilic tracers, which stain the whole cell, it is convincing that the free radicals generated only attack the target subcellular region of the single cell,” they argue.

One particular application fascinates the authors: they envision using the microfluidic probe as a “pen” for cells. “This will enable us to directly write text or draw graphics on single cells for personalized cell marking or artwork,” they explain.

Original publication:
Qiang Zhang et al.; "In Situ Stable Generation of Reactive Intermediates by Open Microfluidic Probe for Subcellular Free Radical Attack and Membrane Labeling"; Angewandte Chemie International Edition; 2021

Facts, background information, dossiers

  • fluorescence imaging
  • cell analysis

More about Tsinghua University

  • News

    Golden Ball in a Golden Cage

    Researchers have synthesized a tiny structure from 32 gold atoms. This nanocluster has a core of 12 gold atoms surrounded by a shell of 20 additional gold atoms. As the scientists report in the journal Angewandte Chemie, the unusual stability of this cluster results from electronic interact ... more

    Microtube with Built-In Pump

    Driven by natural or artificial sunlight, a novel “microtube pump” transports water droplets over long distances. As reported by Chinese researchers in the Journal Angewandte Chemie, the pump consists of a tube whose properties can be changed asymmetrically through irradiation. This results ... more

More about Angewandte Chemie

  • News

    Degradable sugar-based polymers may store and release useful molecular freight

    Degradable, bio-based polymers offer options for chemical recycling, and they can be a tool to store and release useful molecules. Scientists have developed a class of sugar-based polymers that are degradable through acid hydrolysis. The researchers also integrated “cargo” molecules in the ... more

    Inverted Fluorescence

    Fluorescence usually entails the conversion of light at shorter wavelengths to light at longer wavelengths. Scientists have now discovered a chromophore system that goes the other way around. When excited by visible light, the fluorescent dyes emit light in the ultraviolet region. According ... more

    Useful “Fake” Peptides

    Some useful drugs consist of peptides acting on their protein targets. To make them more efficient and stable, scientists have found a way to replace crucial segments of the peptides with ureido units. These oligoureas, which are composed of urea-based units, fold into a structure similar t ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by:


Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE