Jul 7, 2011
Nanoindentation of myelinated axon evaluates nerve regeneration
Many human diseases are caused by the demyelination or polyneuropathy of myelin sheath – a multilayered structure that surrounds an axon and plays a critical role in the transmission of nerve impulses. By measuring the mechanical properties of myelin sheath at various stages of development using depth-sensing nanoindentation, scientists in Taiwan hope to find out more about its crucial physiological processes.
Biochemical factors and pathological phenomena concerning myelin have been studied before. However, the mechanism leading to myelination and demyelination is still unclear. In particular, the mechanical properties of the myelin structure can be difficult to measure.
Thanks to the progress of nanomechanical instrumentation, dynamic contact apparatus combined with continuous stiffness measurement provides depth-sensing nanoindentation, which is capable of studying the multilayered and complex myelin structure.
Three major types of the developed myelinated structures were prepared by co-culturing PC12 with Schwann cells in vitro. As shown in the figure, stiffness profiles on the multilayered nanostructures were characterized in situ. This information, acquired instantaneously via an infinitesimal and continuous loading-unloading process, reveals the multilayered properties as profiled by contact stiffness and shows the myelin structures at various stages of development.
By investigating the inner structure of developed myelin, the researchers hope to associate the data with the quality of nerve regeneration and to discriminate its development process. Furthermore, the technique is promising for pathological studies to demonstrate the structural changes caused by nerve-related diseases.
The team published its work in the journal Nanotechnology.
About the author
This study was conducted by a team of researchers from National Cheng Kung University, which includes scientists from the Departments of Materials Science and Engineering (MSE), Neurology, and Mechanical Engineering. The first author, Wei-Chin Huang is a PhD candidate at MSE. The corresponding author, Prof. Jiunn-Der Liao, is chairman of MSE. Profs. Chou-Ching K Lin (MD) and Ming-Shaung Ju provided technical support. The team is currently interested in the nanomechanical characterization of bio-tissues and cells, and relating the information to the biophysical properties of the samples.