A device designed to monitor how cells move could help scientists understand cell migration, important in processes from embryonic development to wound healing and cancer metastasis. Developed by Chinese scientists, the team claims the microfluidic system could form the basis of high-throughput drug screens. 

Holes in the cell monolayer (bottom left) are filled (stages shown clockwise) as cells migrate to heal the artificial wounds

Jing Cheng and colleagues at Tsinghua University, Beijing, made the lab-on-a-chip style device which creates artificial wounds and monitors the surrounding cells as they move to heal the wound.   

Whilst wound assays are the most common way to measure cell migration rates, they are often based on optical measurements which are not quantitative and can suffer from low repeatability. The new method avoids these problems and 'the device is almost fully automated,' says Cheng. 

In the device, a self-assembled monolayer, made from an organic thiol, forms on a gold electrode and is surrounded by a monolayer of cells. An electrical pulse is applied to the electrode, which desorbs the thiol to create a void - an artificial wound - in the cell layer. As cells migrate into the void, their migration rate is measured by following how the cell growth affects the current in the electrode.   

The Chinese team tested the device by measuring the migration rates for four different cell types. In further experiments with the anti-migratory agent colchicine, the researchers demonstrated that the device can detect changes in cell migration rates caused by small molecule drugs. This suggests that it could be used in drug discovery, says Cheng.    

'The cell migration assay on chip has important advantages compared to conventional methods such as being quantitative and real time,' says Helene Andersson Svahn, an expert in nano-biotechnology at the Royal Institute of Technology, Stockholm, Sweden. 'It will be interesting to see the impact of this new technology in drug screening and cancer therapy, for example.'    

Russell Johnson