Washington, Dec 26 (IANS) Using an atomic force microscope that details images of nano-structures, researchers have discovered changes in the collagen component of bone that indicate its health - a step which could lead to new methods of diagnosing osteoporosis.

Collagen, the most common protein in the mammalian body, is present in bones, teeth, tendons, skin and arteries, making up to 35 percent of the body's protein. Bone is a composite material made up of a flexible collagen matrix impregnated with and surrounded by a stiffer, stronger mineral component.

Though much is known about the importance of bone health to overall health, there's a critical lack of knowledge about the sub-microscopic structure of bone and how collagen and mineral - and the interactions between them - contribute to properties of healthy and diseased bone.

'Our initial question was, could we discover more about the nanoscale structure of the collagen in bone, using the technique of atomic force microscopy,' said Mark Banaszak Holl, University of Michigan (U-M) professor in chemistry and macromolecular science and engineering, who led the study.

This microscope - a futuristic imaging tool - measures and manipulates matter at the atomic level, works something like a phonograph with a motion detector attached to its needle.

As the tip systematically moves across a bumpy tissue surface, the motion detector records its every movement. The result is a 3-D image of the surface's contours.

Using such an instrument, the researchers were able to see and measure key features of collagen fibrils in mouse bone.

Each collagen fibril is made up of many individual collagen molecules packed together in a staggered array that resembles a railroad track.

'As opposed to a single value, our data indicate that normal bone contains a distribution of collagen fibril spacings,' a U-M release quoted Holl as saying.

'This ability to measure fibril spacing and to distinguish between normal and diseased bone... also has important implications to the future diagnosis of disease in bone and perhaps other collagenous tissues,' Holl added.

These findings were published online in Bone.