Researchers from the Centre for Cooperative Research in Biomaterials (CIC biomaGUNE) have developed the STREM (Stress Relaxation Microscopy) experimental methodology for complete mechanical characterisation of different biomaterials. The new method, whose description and preliminary application were published in the Journal of Biomechanics, may become a powerful detection and diagnostics tool for many diseases such as breast cancer.

The work was carried out by a joint research group involving Susana Moreno-Flores and José Luis Toca-Herrera, from CIC biomaGUNE, María del Mar Vivanco, from CIC bioGUNE, and Rafael Benítez from the University of Extremadura.

STREM fundamentals lie on the relaxation of the mechanical stress applied to biomaterials under constant deformation. This approach, together with classic atomic force and optical microscopy, provides a multiparametric image describing the biomaterial. Therefore, the methodology generates 3D topographic maps together with images of the deformation caused by shear stress, the total and dissipated deformation energy and the relaxation times in viscoelastic processes.

In particular, STREM was applied to living breast cancer cells (MCF-7), representing complex cells. Some physical magnitudes such as cell deformation due to local shear stress and relaxation times on the cytoskeleton and cell membrane at micrometric scale were determined.