Cancer cells are unlike normal cells in many ways. For example, they have different mechanical properties and adhere to other cells and the extracellular matrix in a different way. The variation in cell surface "brushes" revealed by Sokolov's team is almost impossible to quantify with other microscopic methods, such as optical or electron microscopy. The brushes consist mostly of microridges and tiny "hairs", microvilii, which are needed for cells to interact with their environment.

The Clarkson team obtained its results by analysing force measurements taken from the cell surface using an atomic force microscope (AFM). By analysing the deformation curves, the researchers found a two-layer behaviour in the cells. They then developed a model to decouple these two layers so that they could study them separately.

"Normal cells and cancer cells should interact very differently with micro- and nanoparticles because of the differences in their surface geometries," Sokolov told "This phenomenon could be used for cancer detection and potential treatment through drug delivery." For example, fluorescent silica particles might be employed to detect cancer cells, he explains.

The team now plans to develop a better model so that more-precise surface features can be detected. The researchers also hope that biologists will make more use of AFM techniques to discern features like brushes on cells. "A lot of biologists think that the AFM is very limited for use in their subject field but our work shows that it has much, hitherto hidden, potential," added Sokolov.

The work was published in Nature Nanotechnology.