Scientists Measure Differences Between Normal and Cancer Cell Surfaces

May 05, 2009 by Laura Mgrdichian weblog
Scanning electron microscope images of a cancerous (left) and normal cell, showing the differences in cell "brush." Image courtesy Igor Sokolov.

(PhysOrg.com) -- Scientists know that cancerous cells and normal cells have different physical features, but the details of these differences, and why they occur, are not well understood. In a recent edition of Nature Nanotechnology, researchers report measurements of certain physical differences between the surfaces of normal and cancerous cells, suggesting a new way to characterize cancer cells and a possible route for detection.

The group, composed of researchers from the Nanoengineering and Biotechnology Laboratories Center at Clarkson University, was studying human cervical . Led by Igor Sokolov, they focused on the cells' surface features, including microridges and hair-like microvilii, which, perhaps acting like sensors, are one key way that the cells interact with their environment. Together, these features form a cell's "brush."

They found that normal cervical cells tend to have a brush layer consisting of a single average length - 2.4 micrometers (millionths of a meter) - while the have mostly two typical lengths - 2.6 and 0.45 micrometers. Additionally, their analysis showed that the long cancer-cell brush is about half as dense as that of the normal-cell brush while the short cancer-cell brush is more than twice as dense.

The group made these findings using an (AFM), a high-resolution device that can resolve details down to a fraction of a nanometer. The AFM works by scanning a surface with a tiny cantilever, a beam supported on one end so that it can move up and down. In an AFM, the beam is tipped with a nanometer-scale curved needle often made of silicon or silicon nitride. When brought near a sample, forces between the needle tip and the surface cause the cantilever to deflect. When the entire surface is scanned, the result is a set of force data that represents a surface map of the sample. By analyzing the forces, researchers can recover the nature and type of surface interactions.

In previous studies, scientists treated the surface of a cell as flat. In their work, the Clarkson researchers used various supporting techniques, including electron microscopy and confocal scanning laser microscopy, to show that the cell surface is sufficiently "brushy" to be visible in the AFM data. The researchers processed the forces using a "brush on soft surface" model, the type of model used to study polymer brushes (polymer chains tethered to a surface). Prior to this work, scientists had not looked at cell brush in this way.

The AFM method has an edge over other microscopy techniques, such as electron microscopy, because it can work with viable cells, avoiding misrepresentations of the cell structure and saving time on sample preparation.

More information: Nature Nanotechnology advance online publication 12 April 2009, DOI:10.1038/nnano.2009.77

© 2009 PhysOrg.com

Explore further: Team finds electricity can be generated by dragging saltwater over graphene

add to favorites email to friend print save as pdf

Related Stories

New ORNL process brings nanoparticles into focus

Jun 23, 2008

Scientists can study the biological impacts of engineered nanomaterials on cells within the body with greater resolution than ever because of a procedure developed by researchers at the Department of Energy's Oak Ridge National ...

New highly sensitive AFM revolutionizes nano imaging

Feb 09, 2006

While a microphone is useful for many things, you probably wouldn't guess that it could help make movies of molecules or measure physical and chemical properties of a material at the nanoscale with just one ...

Recommended for you

First direct observations of excitons in motion achieved

Apr 16, 2014

A quasiparticle called an exciton—responsible for the transfer of energy within devices such as solar cells, LEDs, and semiconductor circuits—has been understood theoretically for decades. But exciton ...

User comments : 0

More news stories

Thinnest feasible nano-membrane produced

A new nano-membrane made out of the 'super material' graphene is extremely light and breathable. Not only can this open the door to a new generation of functional waterproof clothing, but also to ultra-rapid filtration. The ...

Wiring up carbon-based electronics

Carbon-based nanostructures such as nanotubes, graphene sheets, and nanoribbons are unique building blocks showing versatile nanomechanical and nanoelectronic properties. These materials which are ordered ...

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...